Okay, but blowing on a sail to go faster is actually a thing. Mythbusters even stated that they did their experiment in the worst method (i.e., not using modern designs and methods), and still found that a fan on a sail could make it move. It's not free energy, but let's not ignore how cool sails are.
This sounded very wrong to me, so I googled and apparently they had a setup where the reflected air from the sail caused a net flow in the opposite direction allowing them to move forwards. But that is less effective than just blowing the air straight backwards without a sail.
I don't own one of these, but that sounds actually useful if for example I'm about to climb a big hill and want to pedal at a less strenuous pace (but for more time) than would be needed to overcome the slope.
Too heavy? You just run the motor in reverse which turns it into a generator and adds friction to do generative braking. There really isn't any added weight.
Bikes normally have freehubs, a ratchet on the cassette (sprockets) of the rear wheel, when you stop pedalling the bike freewheels, without that the pedals would keep turning.
This makes driving a motor from the wheel impossible without heavily modifying the normal bike mechanics. That's why regenerative braking on e bikes is rare.
Only very cheap e-bikes have hub motors. They're not a good idea precisely because they don't interact with the gearing system. So you lose that functionality.
It's not worth losing access to gearing just to get regenerative braking because the amount of power being used isn't worth trying to recoup.
Why would it need a direct drive? A mid drive can do the same thing they just don't usually since you'd need to gear for it. direct drives are the most efficient at regenerative braking but they aren't the only type.
Could be done, perhaps, with significant added complexity (and hence maintenance). In practice it is not, to my knowledge there are no mid-mount regenerative system on the market. It is worth noting that mid-mounts are significantly more efficient than hub mount, enough so that even compared to hub mounts with regeneration, mid-mounts have more range for a given battery / wattage. The vast majority of hub mounts also do not implement regeneration.
Generators = put in rotational movement to get power
You already have the heaviest parts on the ebike - motor and battery, just need some capacitors and charging circuit board which are light and not too big.
Cheap electric bikes I've ridden with regen breaking slow you down quite a bit.
It's not difficult to get regenerative braking on a bike it's just difficult to get regenerative braking on a bike that's any good. Hub mounted motors are the least efficient type of motor because it's just directly driving the wheel at whatever speed it can output, with no access to gear ratios. E-bikes that forgo generative breaking in favour of a more efficient motor designs achieve better speeds for any given amount of power usage.
So yeah you can absolutely do it. But it's not a good idea for reasons that have nothing to do with the weight.
Yes, but is it possible to pedal and use regen breaking to recharge the battery when stationary? It does work like that in my car (plug-in hybrid) but I don't know if e-bikes are the same way.
The traditional method of pedaling uphill less strenuously is to drop to a lower gear. You might go slower, but I'd bet even on existing e-bikes with pedal assist, this is something that's already pretty reasonable now days.
Sure, but there are limits. One needs a certain amount of forward speed to maintain balance easily, and there's a maximum speed that can be reasonably pedaled. If the hill is steep enough then in my experience reducing the gearing enough to make pedaling not too strenuous runs into the other two limits.
If an e-bike can have a low battery topped off before the hill starts, then pedal-assist (at least) would take care of the need to lower the gear while going up it.
One needs a certain amount of forward speed to maintain balance easily
Not true. One just needs to practice static balance. It's a great skill to have so everyone should learn how to do it.
Also you can use the lowest gear going almost a walking pace and climb up really steep hills. That's how we do it on MTBs. It also requires practice and good balance.
Ah, that would be a nice skill. I might even be better equipped for it now than when I was young because I've gotten into roller skating and improved my balance that way.
As someone who sucks at physics, I'm convinced that Trollface has proposed so many solutions around the internet to provide free energy, but the capitalists are conspiring to sabotage him, just as they did to N.Tesla.
I remember the one where he uses two magnets, and the one where he wraps his head with a bag and puts a plant inside it, so he can swim with infinite O2 supply.
OR hear me out, AI was trained on these kind of posts. Emoji were overused in similar fashion before the AI bubble. Remember when crypto and NFT was all the rage? Crypto bros were all posting like this. And it worked on gullible people, so now AI does it too.
It's funny how everyone thinks they're AI detectives now.
It's a good idea, even if it can be ruled out. That person should offer more ideas. All of those Newtonian physics people never seem to offer up ideas.
They can understand some basic concepts before you get into the math. Especially potential energy turning into heat, which children experience firsthand frequently. IMHO kids these days seem to understand energy more easily than we did; I think it's because of video games.
Likely not only drafted with AI, but only pursued because he entered the idea into ChatGPT and asked "is this a good idea?," and uncritically took ChatGPT's enthusiastic support as vindication.
Tbf it wouldn't be a perpetual motion machine because batteries -- even rechargeable ones -- have a limited capacity that reduces over time because they are a chemical reaction, the components of which degrade over time.
This guy apparently doesn’t understand the first and second laws of thermodynamics. However, in his defense, this is sorta how regenerative braking works, but with less complexity.
This is a normal trajectory for college freshmen. Get introduced to a bunch of basic ideas. Spitball and try to see how you can apply them. Start running into all kinds of caveats and engineering hurdles. Go back to class. Bother the RA. Maybe actually learn more about what you're trying to accomplish. Become a better engineer.
Not believing you can create a perpetual motion machine should practically be an entry requirement. If you think you can you need to go back and do high school science again.
Nah, engineering students often forget and design perpetual motion machines. Usually, they remember why that is stupid and impossible before they post it publicly where I can haunt them forever.
It should be a graduation requirement. It really should be...
I once had an exam question that began with the phrase "ignoring thermodynamic principles...". That question really threw me, it basically asked what would happen under XYZ situation if physics didn't exist. How the hell am I supposed to know that?
My LinkedIn feed is like 90+% AI at this point. I don't know why anyone bothers looking at the "content" on that website anymore. I only see it just incidentally on my way to the job listings and I am always shocked at how terrible it is
I was about to say, could this post possibly have any more emojis? Although, from my knowledge of existing MLM hunbots I unfortunately already know the answer lol
Yeesh... the entire thing is so much secondhand embarrassment it makes me want to delete my entire profile just for the sake of it regardless of never using the actual site
Either he's lying about being a mechanical engineer or the barrier to entry to become a mechanical engineer is embarrassingly low.
It this guy seriously proposing a perpetual motion machine for the purposes of EV charging? Also not that it really matters but who the hell has range anxiety on an electric bicycle. You get 30 miles out of those things easily, what sort of bike rides is he doing where you have to recharge that more than once a month?
He should try recharging a solar panel with a light powered by the solar panel. Just achieving infinite power.
Thanks, I don't doubt it. Biggest issue is that I have significant anxiety about doing any riding after a really close call some years ago. A car was going something like 50 mph on a 35 limit street, and was inches from hitting me from behind. Technically it did hit, but only enough to barely whiff past my body, and put a small dent in my rear rack.
I work 18 kilometres away from where I live, that takes me 45 minutes on my acoustic bike. That's just a little longer than 10 miles. The round trip is ~an hour and a half
He's probably lying. While the bar is pretty low for entry level M.E.s, it's not quite that low yet.
As an old Toolmaker, I have made my share of intern wannabe MEs cry after crushing their idiot ideas. I swear, the older engineers would send those clowns to me just so I would beat them about the head and neck with a stick.
(I have a Daughter that has a PhD in ME. I warned her to turn down the free lobotomy offer upon finishing her degree. She listened and is now a happy and very, very smart Dr. of Engineering working with EV and HVAC systems)
That's just regenerative braking on a bike. Without batteries.
In theory that idea isn't actually bad although I suspect in practise the mechanism would be extremely complicated and would be liable to jamming it in opportune moments. That said doing this electronically is already a thing, although not really in e-bikes.
Dynamo lights work off a similar principle. It extracts energy from pedaling or the wheels spinning to power lights on the bike. You can feel the drag and it's probably about 5w of power. Really not a whole lot. About the same energy you'd save from wearing smooth socks or cleaning the chain for some perspective.
The extra weight required to implement a solution like yours would probably rob the rider of any gains. But in a very theoretical sense it could work if the material weighed an insignificant amount.
Either that, or he's not very smart, had a thought, poppet it into ChatGPT, and ChatGPT as it tends to do, affirmed his dumb idea, and he ended up asking it to make a Linkedin post for him on the idea.
I've seen similar stuff from students who think they've cracked how something works, only to be incredibly wrong, because they only know half of what they need to, but don't know enough to understand how little they know. It's part of the journey of getting sorta-good at something though.
It's almost as if one object perpetually moves something that creates a form of motion perpetually to continuously move that first item. Like a continuous motion machine or perpetual movement apparatus. Something like that. I feel like my naming is close, though.
This guy is only telling us part of the truth. You actually need three batteries. The third battery is hooked up to a solar and wind generator. Only then can you achieve true energy independence.
So you're on your ebike, going 15mph. Using 140w or so. You're spending 15-20w on the drivetrain, and the remainder is entirely aerodynamic drag. You're putting 120-125w into making wind move. You're also losing 5-10 watts to the drive electronics and dashboard. So your total power use is 150w.
If you're going to recharge a battery. In the same time it takes to ride, you need to get at least 150w of power into another battery. Sadly, batteries don't actually "just cleanly charge" there are some losses, but since we're going to take an hour to charge it, lets call it 5%. So to fill up that battery we need 157watts of input power.
Your bike, moving at a steady speed, is absorbing 150w of power. If we want another 155w of power, where is that going to come from? If we take it from.. say.. the front wheel, we are now absorbing another 155w of power. So to maintain the same speed, we now need to push the bike along with 305w of power. And.. now we need a bike that makes 305w of power, to go the same speed we were going with 150w. .... And we're only generating 155w.
There is no free lunch. If you're doing work, you need to get that power from somewhere.
Like, the whole point of these things, at lesst as I see them, is that you get that free lunch on the way down a hill, then when going up a hill, well yeah, you still aren't gonna like, be 1:1 be able to power right back up it, but it will be easier going up that hill than if you did not have your free energy lunch on the way down.
This then results in you not needing to expend as many literal calories going up a hill, so now, you don't need as much food to recharge after a ride, thus you do actually on net come away with at least a portion of a 'free lunch', in that you don't need as much food.
But yes, I will give you that... the overall weight added to the bike from the batteries would have to be in a manageable range, so that the uphill assistance is not just entirely used on uh, pulling its own weight.
The problem with "go down a hill" is that the LinkedIn idiot wants to use the power of one motor to generate power in the other. Regenerative braking only needs one motor and it acts as a generator when braking.
I mean... you can do regenerative breaking in a hyrbid car, where the main LiON battery is also charged from the ICE engine.
I had a hybrid Prius C that worked this way.
Roll it down a hill, far enough, in the right mode?
Recharges the main hybrid battery.
And then, you can also put it into a low power, EV only drive mode. Can't do inclines or go fast, but you can get up to about 20mph on flat terrain.
Like, I've done that at least once, as a kind of makeshift jumpstart sort of thing.
Presumably, it may be possible to scale such a system down to a bicycle, or maybe moped or motorcycle.
And the LinkedIn guy specifies that there are two different batteries, which are capable of transfering power between each other.
So their system is regen braking -> bat 2 -> transfer -> bat 1 -> drive motor.
Personally, I don't even see why you need two distinct batteries, just have a powerstation type thing with a some software that regulates power uptake and output intelligently.
What he's said can be interpreted that way, if you add some words he didn't say into this post...
... but he didn't actually say that.
A 'continuous self charging loop' is not the same thing as... that, but which also generates infinite energy or is somehow overunity, over 100% efficient.
That just means there is a continuous loop by which energy can flow from the regen braking to the motor.
It doesn't mean that energy is always flowing through that loop... it just means that some amount of energy could be.
It doesn't mean that power coming into the motor or batteries always exceeds the maximum power consumed by the motor.
(that would infact be very bad and cause the batteries to explode/burst into flame at some point if we're talking about LiON)
Continuous loop is... an actual electrical engineering term, and its actual meaning is basically as I have just described.
Now sure, if this actual LinkedIn post is rather recent, well its rather cute that he seems to think he is the first person to come up with this idea...
But, it is also cute that the vast majority of commenters in this thread are suggestible (by way of being mentally framed with a narrative by the comm this is posted in and the post title) and have either poor reading comprehension, or just didn't bother to actually read what this 'lunatic' wrote... and are acting like they're better engineers than this guy, that he's bonkers... when in actuality, they're all showing their own asses unintentionally, proving that they don't know basic electrical engineering terms.
For this guy to have actually been trying to describe a perpetual energy devicre, he would have had to say something like 'a continuous- ly self charging loop that is over 100% efficient'.
He even specifically said his goal was to reduce the need for external charging.
Not eliminate, which would imply he thought it was overunity, but no, just reduce, which... would indeed be the result if his system worked and granted an extra 10% or 20% to overall EV bicycle range.
Yeah, in engineering, as well as language, precision and small details can make for large differences in the end result.
You do get about 5-10% more range with regen on an ebike, the downside is it needs to be a hub motor which sucks at climbing hills, and one with no internal clutch which means pedaling with the motor off wastes a ton of energy.
Apparently regenerative breaking efficiency in bikes is rather limited (small motors / generators, high friction). It still increases the range a fair bit (enough to be a better investment than bigger batteries), but efficiency is still not as high in bikes as in bigger vehicles which can drive more kinetic energy into bigger generators with better individual wheel control
Some paper says ~25% extra range in bikes at the high end vs ~50% energy savings in Japanese trains. Different units for those numbers, but you can infer that trains has much more efficient regenerative breaking because that number indicate a doubled range for the same amount of energy used.
Does he have a fundme or patreon page? I think it's worth supporting his research if it can be applied to cars and trains one day.
If somebody is an airplane engineer, is it possible to do something like that with planes? It would be great if planes could become environmentally friendly with such technologies.
There was actually a prototype environmentally friendly airplane designed and tested back in 2000 during a genocide in Yorkshire that I feel like isn't talked about enough. The plane, using bicycle technology, was successful in transporting all of the local populace to safe territory with the help of a veteran Royal Air Force member and an American entertainer posing as a flight specialist. Really an incredible story and there's still footage of the flight. but I don't know the status of the airplane today.
Is this serious or a joke? Regenerative braking and other energy recovery methods have been standard on electrified vehicles for decades. Electric planes do exist, but the problem is that the mass to thrust ratio for electric motors is worse than jet engines. Most successful ones are pretty small and light.
I think you don't fully grasp the genious, magnitude and potential of Aryan Bhambure's invention. A continuous self-charging loop would essentially eliminate the time wasted on charging batteries. There would be no limit on the range of a car.
That's even more interesting for planes, given that a transfer is possible. As others have mentioned, the technology is heavy, which could make it unsuitable for planes. But if those limitations can be overcome, direct flights between all places of earth become possible. I think that's an advancement to humanity that's worth our support.
Unironically, I would enjoy a bike that I could pedal at a constant speed, charging the battery all the while. Give me a display that indicates my pedaling speed so that I can tailor my exercise and you’ve created a moving stationary bike. I hate having to stop at lights and whatnot, so a rotation-based stabilizer would be nice at speeds below 10 km/h as I pedal the equivalent of 30.
Really, it’s just unfortunate that the engineering doesn't work out for momentum->chemical energy unless you’re biking at a professional level and willing to cruise slowly or charging the battery at home. Bleh
If your actually mobile bike can also be used as a makeshift generator, to feed into a home backup battery?
Yeah maybe not huge levels of appeal there, but it is a neat utility feature.
Maybe I've played too many zombie survival games with base building... or, maybe I am aware of the shockingly shitty state of the US power grid.
Also:
If you have a bike, and battery/powerstation like that?
That leads to a potentially amazingly ironic situation where you effectively jump start a dead ICE car ultimately from a fucking bicycle, if you can hook your battery/transformer/power station thing to charge a portable car battery jump starter.
My e-bike dosen't have it and it's sounds pretty complex to add efficiently on a bike. It's just take like 5 hours to charge in a normal output. And every corporate building have outputs for e-bike so I can charge while working.
Electric cars already do this and I'm sure there are some smaller electronic mobility devices that also do regenerative braking. It's not exactly a new concept.
What added weight? If there already is an electric motor on the bike you can just use that as a generator during braking or coasting down a hill. That’s what EVs already do.
Unrelated, but the pedaling cadence people have on ebikes bothers me. I'm always seeing folks in a high gear slowly pedaling. I'm like dude you're sacrificing watts! Pedal faster on a lower gear, you'll use the same energy but go faster.
You get into the habit of just ignoring the gears because it doesn't seem to make any real difference. Sure been in a lower gear is more efficient but it doesn't feel any different so you don't think about it.
I thought it was the other way around, where doing the higher force version results in higher efficiency, so you use more energy to achieve the same effect (when you use the lower gear and pedal more). It's easier to generate force but takes more energy to apply that force over the same diatance (because the converted distance you're applying it to on your end is longer).
The optimal method for range is basically PWM (pedal then pause and repeat) at the highest output that you can sustain (up to a limit, where both increased losses from the speed during bursts and from your muscles becomes too high)
Spinning in low gear uses the human body's capabilities more efficiently. Whether more or less distance is spun is less important because it is so much easier to pedal low gear/high cadence. It's the difference between jogging and sprinting. High cadence/low gear keeps it a mainly cardiorespiratory endeavor while low cadence/high gear is just your quads vs your ability to suffer. You can look at the legs of distance (tour de France) vs sprint (track) cyclists to see the difference in body composition from each approach. I'm not arguing with your reasoning. I've only ever measured watts not watt/hours.
Hmm, when I go out for a ride my muscles always feel better if I'm keeping my cadence high vs grinding in a high gear. Like muscles don't act the same way a motor does. And if I'm on an ebikes I want to get the most of what my muscles are doing.
But maybe grinding in a higher gear is better for endurance, IDK?
There was this browser game (on the BBC website IIRC) with a Wallace and Gromit theme, in which you build stuff.
It had a level in which you make a vehicle-ish contraption and see how far it goes ^[or more like whatever contraption you can make to get the dummy to go as far as possible. Could even be a cannon, launching the dummy.]. I managed to setup a motor and generator in such a way that it effectively increased the vehicle's range by quite a bit.
I don't remember well enough now, but I think the generator didn't give as much resistance as the energy it was creating.
I had this idea 30 years ago lol. Bicycling in headwinds in windy and flat Denmark gives you a lot of time to think of dumb shit like that, like what if I put small wind turbines on my bike which generated electricity to give me a boost?
We've had windmills as part of the landscape here for a long time after all, so it wasn't exactly rocket science to think that one up.
Actually, that jostled my memory a bit, I just remembered that I saw a veritasium video about this a month ago or so, while it wasn't about generating electricity and using that for a motor, but just straight up wind to mechanical energy.
Nobody will even consider listening to a pitch to schedule a phone call to listen to an elevator pitch for consideration for a short phone interview to be considered for a meeting to speak with the board, unless it includes AI for some useless reason.
My hybrid Prius C had this, and yes, you actually can build up some useful amount of charge from just rolling down a decently large or long hill, and you can also run the car on pure EV mode, though you're probably not gonna top 20 mph on a flat road.
Obviously this does not create an over unity situation or perpetual motion machine, but, if this guy can figure out a way to put a regenerative braking type device onto an E-Bike, or maybe motorcycle/moped, in a way that isn't stupid expensive...
That could increase overall range, and I think it would be neat.
Though I... don't really know why you wouldn't just use one battery for the whole system, just have a modulation/regulation system for it.
It's not free energy, but there's at least one bike called the Pi-Pop that works this way in order to spread the energy demand from hills across more distance for the rider. It's an electric bike you can't plug in, it only charges from moving
There is one particular mine, I forget where, and they extract ore at the top of the hill and carry it down in electric trucks that gather more energy on the downhill run than they need to get back to the top when empty, so they never need to be charged.
Oh, yeah, I had that issue for a while. I think my computer clock was differing somehow from the server clock, and I was always a few minutes in the future.
Yes, many electric bicycles power themselves while going down hills or costing. As for the other idea that you could recharge them just by pedaling ... That exists already. Almost nobody wants it because it's easier to plug your bicycle in. The point of the electric bicycle is to do less work, not to do more. Otherwise you would get a regular bicycle because it weighs less.
Regen braking exists, and everyone does want it, because it gives free power when you hit the brakes. The reason nobody adds it is because up until recently, you could only have coasting or regen braking, and not having to pedal literally all the time is just far more important for bikes. There's a recent tech, freegen? Called something like that, it lets you have both regen braking and coasting,
Do most e-bikes not charge from the pedals? Combine that with regenerative coasting/braking, and this isn't really that dumb. Like yeah, obviously thermodynamics, but an E-bike with pedal charging isn't a closed system.
Regenerative braking is not worth it on bikes... it's worth it on cars because you are slowing down over one and a half tons of weight and going much faster so there is serious amount of energy to be recovered
You’d basically need electronic braking for this to work. Which should be theoretically possible since we already have electronic gear shifts. Would be tricky to get the feel right in the transition between motor to friction.
If you extract enough energy from pedaling to charge a battery while also travelling, you'll definitely end up using more power than less. Which absolutely defeats the purpose.
All these "smart" ideas would already be implemented if they were actually clever and deployable. The reason no one does it is because physics doesn't work that way.
Aw man, Lemmy finally got a LinkedInLunatics instance? How long has this been here? That was like the last thread I've been hanging onto with reddit. Finally, this place feels like a genuine alternative 🎉
It would wash out. Any energy collected would be at the cost of resistance. So add fans to add wind resistance. You could collect energy from coasting and braking, but that's just tech we've been using for years in cars, and it comes at the cost of movement. It actively slows you down because the energy has to come from somewhere. And since energy conversion is hardly one-to-one (loss to heat, etc), storing it into a battery and then pulling it out again means you won't gain as much as you lose.
Energy cannot be created or destroyed. If you are generating energy, you're taking it from somewhere, and on a bike, it's from your forward movement.
Okay, I get that, but wouldn't the collection be a separate system? The energy is being created by the battery, then a separate system collects the energy.
Yes, you could collect energy while coasting down a hill, but it would slow you down. Which is fine if you want to slow down; this is the basis for regenerative braking. You might be thinking that a pinwheel spins like crazy in the wind, and that's just free energy. But a pinwheel doesn't store anything. To store energy, you need to add resistance, and the more you add, the more energy you collect and the harder it is to spin the wheel.
So at the end of the day, you've got a fan at the front of the bike that is either spinning quickly with little resistance and storing little energy or one that is spinning slowly and collecting more. And the slower it spins, the more pushback there is against your forward movement.
Despite there being two batteries, this is still a single system which uses energy to propel the bike forward and collects energy by preventing the bike from moving forward. They offset. The only way to have the energy to propel the bike is by introducing energy from another source (not related to the movement of the bike) such as a battery charged ahead of time or calorie loss of the rider (active pedaling).
Now you're introducing potential energy (a hill), which will be used up (or rather be fully converted to kinetic energy) once you reach the bottom, and you're going to need the same or more energy to go up that same hill again (depending if you take resistance into account).
We already have tech for capturing kinetic energy for later in the same battery used for driving called "Regenerative braking" (cuz' the motor is used as a generator in place of brakes, and you'll need to drive said generator by capturing/braking some of your kinetic energy/forward motion).
EDIT: In other words: You could just start on a really high hill and you'd be able to use the weight of the bike and yourself as a "battery", never needing any actual battery/motors/wiring/etc.
Imagine it like this, you have two glasses of water, labeled “speed” and “chemical.” You can only transfer water between glasses. And messily. It’s a sum of water, a specific weight of water between the two glasses that you own. In placing the water elsewhere, you haven’t done much besides lose a portion in the transfer. You can absolutely do what you’ve said! It will, unfortunately, just be a transfer from the speed to the chemical glass. You’d just lose a bit in the transfer.
Okay, I admittedly know nothing about this, so bear with my ignorance. Aren't you just moving gears? It would generally be like an auto engine where you have all of these explosions that push gears. You're just moving the gear in one direction as a click, click, click.
Turn off the engine of your car, does it keep rolling at the same speed forever?
Where are you going to get that power on a bike? Your legs. Do you really want to peddle away to charge a battery at SIGNIFICANTLY reduced efficiency, then with even more loss of efficiency discharge the battery into an electric motor? Or do you just want your energy going directly to the wheels?
The person in the post is trying to come up with an infinite source of energy which is not possible.
On an e-bike you would be losing significant portion of energy from propelling the bike, friction, air drag and heat loss. You might be able to put a small amount of energy back in from pedaling, going down hills or even braking, but certainly not enough to make it perpetual.
Perpetual motion machine are physically impossible based on our current understanding of physics. Many, many people have attempted to create them, but they all fail from the reaaons above.
A wind turbine collects the energy of the wind through movement. A gear can give more "force," so I'm assuming more movement of something. If you have 2 different systems, one that collects the movement, or more "force," and one that is making the bike move, why wouldn't that be close to collecting as much as you put in. You'd have to charge occasionally, but not all of the time.
With the bike, the battery (and pedaling) is the source of your net energy output. Losses from friction to the ground and air drag will be the most significant net consumers of the energy. It doesn't matter how the rest of that energy is moved around within the system(s) of the bike.
Ultimately, what determines the distance you travel is the capacity of the battery and what external environmental factors affect the bike and by how much. Biking at 3m/s will have less air drag than 10m/s. Friction will be affected by the surfaces you go over, with something like mud taking more energy compared to something smooth like smooth concrete.
Conservation of energy, basically it's not that it wouldn't work "at all" or appear to anyway but that it wouldn't work as desired. You can't recapture the power used to propel the bike because it's being used to propel the bike. Adding a collector increases the power needed to turn the wheels and basically makes the drive battery's job harder, so it runs less efficiently and runs out faster, battery 2 does charge and can be run from, but in the end you end up with less range due to the stacking inefficiency and energy leakage. The closest functional system to what they are talking about would be a breaking system like electric cars use.
If you are drawing energy out of a system them that amount of energy is removed from the system. A freespinning gear won't generate electricity. It has to be pushed, which requires more energy from the power source, and is always a net loss because of friction.
That is before the added weight of the additional batteries.
So trying to get energy back from a moving cycle will result in a less efficient bike.
You can power lights or a phone charger with a dynamo connected to the wheel and minimally noticeable drag/resistance. You can recharge a drivetrain with regenerative braking which requires high end motors to use the motor like a dynamo
Yes, you can collect some of the kinetic energy and put it back into a battery with regen braking, but most of the energy put into such a system will be lost to heat/friction, drag, drivetrain inefficiencies, battery inefficiencies, recovery inefficiencies, etc.
In the lunatic post, he's not talking about regen braking. He's talking about using the same system that moves the vehicle to simulatneously charge a battery. Which means you're taking some of the energy which would normally move the vehicle and shunting it into a recharging "circuit" - which introduces even more losses.
The end result would be a machine that is less efficient.
That makes sense, except the collection of the energy can be less than the energy expended, like an automobile or wind turbine. Then it could be a perpetual machine.
It would be like this:
Energy in => convert to a gear that makes it way more energy => store energy, repeat.
nah, see, a gear is basically just a fancy pully. it can make it easier to pedal up a hill, but only by making you have to pedal many more times to do so. each turn of the crank arms takes less force, but you have to do it many more times. it isn't actually reducing the energy requirement, and it isn't multiplying your energy input.
what you're describing here would be some kind of magic.
It could be an OK idea that just wasn't explained right. Maybe he just wants regen braking but with one wheel for charging and the other wheel + separate battery for power at any given time. Energy would come from pedalling and hills. None of that was explained though
Is there anyway to like, siphon off the energy though? Like say, you pedaling produces 600kJ/hr. You have 400kJ/hr going into the bike to produce motion, but then 200kJ/hr goes into a battery. You'd move slower but generate stored potential energy.
I'm not really sure why you would want this, other than the concept of a self-charging electric bike, but on paper it sounds possible?
Yeah, it's called a dynamo, used for decades for powering headlamps on bikes before small batteries and LED lights. Still, the energy generated is pretty small.
You would need to output far more than twice the energy that you would get out of it and the effort to pedal would be significantly increased as you would have additional weight to the bike on top of whatever it was drawing.
Taking 1/3 if your pedal power would be like trying to bike through deep mud just to have a small boost later.
A normal bike drivetrain is around 95% efficient, which is more efficient than the Regen circuitry you could get in such a form factor. Therefore it makes more sense to use pedal power for direct propulsion since that will directly reduce battery more efficiently than using it for charging.
This is different than a series hybrid because car drivetrains are very inefficient compared to a bicycle.
I had one, and it was shit for regen braking, but also terrifying. It was a dual 1kw motor (front and back wheels both powered) bike with a car battery sized LiFePO4 battery bolted over the back wheel. Incredibly top heavy, overpowered such that the front wheel would spin on the road at takeoff, and the regenerative braking was a fixed amount of deceleration. Meaning it would put, say, 100 Newton's of torque consistently when triggered. Want to stop from 50km/hr to zero in 10m? Too bad, this bike does it in 25m.
Want to apply just a little bit of braking? Too bad, these brakes are Boolean and they are either on or off.
I believe it was a homebrew import, I bought it off a guy who inherited it after his housemate died (not from the bike)
For context, the max legal motor size here is 250 watts (or 1/8th the power of this bike)
That’s not really how regenerative hybrids work. Turning linear motion into stored energy produces drag, aka braking, so when you hit the brakes, why not store some of that energy that would otherwise just be lost as heat in the brake pads. They’re not just finding extra energy to store for later while you travel downhill unless you have cruise control on (which is to say, unless the car is braking).
In a hybrid corolla, rolling down a hill without pressing the accelerator or breaks will regenerate the battery. Meaning the default is to always try to regenerate at least some energy and produce at least some drag. Letting go of the accelerator at some speed on a hybrid will slow the car to a halt sooner than a non hybrid would.
Well, I knew I’d leave too many loose ends explaining something before bed.
Not quite.
When you coast in a car with an internal combustion engine, you go further when you’re in neutral. Why? Engine braking. When you take your foot fully off the pedal, you restrict airflow to the engine and create a partial vacuum that the cylinders have to work against.
I’m not saying to coast in neutral for higher fuel efficiency. It’s quite the opposite with modern engines that cut off fuel injection when it’s not needed while in gear—and it can lead to increased wear and tear on the engine as well as your brakes fading on long descents. But now you have me covering my ass on every little point, ha. You could look up hypermiling and learn about more efficient driving techniques that way!
Now obviously hybrids have traditional internal combustion engines on board that behave the way we’ve just described. The engineers have also added a level of regenerative braking that is variably applied, even when the engine is not on, so that you scrub speed at a consistent pace. Without this, descending with the engine on or off would feel drastically different, and the car wouldn’t behave as expected at all times. It’s similar to how engineers for fully electric cars have added the “crawl” mode that makes a car idle forward when the brakes are off, even though there is no actual “idle” occurring. It makes the car handle the way you expect it to, and that makes you safer.
It is nice to recapture some energy that is used during the braking process. But only if you need to brake. Otherwise, you’re stealing energy you could be using right now and turning into less energy for later. The process of converting energy into various forms is inefficient, so you will always end up with less than you started, and the more conversions you do the more you lose. Potential gravitational energy to kinetic motion energy is more efficient than potential gravitational>potential chemical>kinetic motion, plus that last step is oversimplified because having the chemical energy turn a driveshaft is actually another kinetic energy conversion compared to gravity turning the wheels directly.
Thus e-bikes could benefit from regenerative braking if the system is efficient enough to overcome the loss of efficiency it introduces via weight and drag, but not from the constant low level capture of energy that would be better used now. Because you don’t get to fuel up an e-bike when the tank’s nearly empty—any toll you pay in inefficiency comes outta your legs and your lungs.
I am not an expert and I am sure I glossed over some nuances.
I'm not sure I get your point. What do you disagree with?
My point was hybrid regen is always on (unless accelerating), if it wasn't, the car would basically coast in neutral. I'm pretty sure hybrid car designers did the math and examined use cases to discover its more beneficial to recover some energy and not coast as much vs coast as much as possible and ONLY regen when breaking. Lightly breaking applies more regen force. Or are you saying they do this for the feeling only and regen is a byproduct.. if it even matters?
I'm not certain, but I'd say applying a little drag to regen on an ebike going downhill will be more beneficial than allowing the riders to go as fast as possible downhill. They could still turn it off, just like I can put a hybrid car in neutral and skip the drag, but why would I do that?
My point is exactly what I wrote! I know it’s a lot, I overcompensated.
Or are you saying they do this for the feeling only and regen is a byproduct
Yes. I said it’s designed this way to feel like a normal car. But it’s a very elegant solution! Far better to do it that way and re-capture some of the energy than let it leave the system, like heat from brake pads.
I'd say applying a little drag to regen on an ebike going downhill will be more beneficial than allowing the riders to go as fast as possible downhill
That “drag” is braking!
They could still turn it off
Like letting go of the brake lever! Far simpler than adding a new always-on brake that you have to manage separately.
but why would I do that?
Because sometimes you want to go full speed down a hill because it’s the most efficient way of moving forward! If you slow down, you have to pedal more later. If you slow down and save some of the energy, you still have to pedal more later, because you can’t save all of the energy from the hill, you can only save part of the energy.
There’s a maximum speed you feel comfortable going on steeper descents, and you manually brake to manage it. That’s the only time regen makes sense on a bike.
Also, because we’re not talking about drag that only exists on the hill. This system exists at all times in a hybrid, and if you implement it on a bike, you’ll be coasting less on flat ground too any time you stop pedaling! Why would we want that? Would you brake in a hybrid when you’re on flat ground to “save it for later”? No! Braking, and engine braking, slow you down.
Not really, even in this hypothetically perfect scenario. Either the hill isn’t steep enough to generate any real excess energy from rolling down it (too much drag and you’ll stop rolling) or it’s steep enough that what you collect is offset by how much energy the ride home requires. The more potential energy you save for later, the slower you’re traveling now. And you can never cross the threshold to where it’s helpful. You’re trying to steal energy from a closed loop. It’s the “bowling ball dropped from face level” problem all over again. It can never get enough potential energy from its trip away to come all the way back.
Storing pedaled energy is pointless too.
Let’s say one regular old pedal rotation propels you 10 feet.
Let’s instead store 20% of that energy for later. You now only travel 8 feet.
While we’re converting that energy, we lose a quarter of it due to inefficiencies in the process. So now we’ve traveled 8 feet and stored 1.5 potential feet.
Pedal 1000 times. We go 8000 feet and store 1500 potential feet. Stop pedaling, turn on battery support, we go 1500 feet, we get 9500 total. 500 less than an unmodified bike. That’s excluding additional system inefficiencies like the added weight of the modifications and the mechanical efficiency of the pedal assist. It’s more efficient to just pedal.
Too much extra weight and resistance compared to the bike and driver for too less benefit. It works fine on a 2 ton box though, despite having two extra wheels.
Hmm, nice exercise in how wasteful cars really are.
An alternator draws energy from the engine spinning but the draw uses more energy than the alternator puts out. It is a conversation system from mechanical to electric power.
The device being described in the image is an alternator: a device that captures energy from the movement of the machine.
I think everyone on this thread understands that alternators do not overcome entropy and that there is no infinite energy, but that’s besides the point.
Did not pay much attention in high school
Look out for v2.0 which also features a sail on the front which you blow to go faster.
Okay, but blowing on a sail to go faster is actually a thing. Mythbusters even stated that they did their experiment in the worst method (i.e., not using modern designs and methods), and still found that a fan on a sail could make it move. It's not free energy, but let's not ignore how cool sails are.
This sounded very wrong to me, so I googled and apparently they had a setup where the reflected air from the sail caused a net flow in the opposite direction allowing them to move forwards. But that is less effective than just blowing the air straight backwards without a sail.
Look for the sail car video from Veritasium. With a chain drive you can out run the wind using the principles of sail propulsion.
When the battery runs out, you pull over and "pedal" to recharge the battery, then you're good to go again!
now that is genius!
I don't own one of these, but that sounds actually useful if for example I'm about to climb a big hill and want to pedal at a less strenuous pace (but for more time) than would be needed to overcome the slope.
Assisted modes already exist, and regenerative braking already exist
But this joke is more funny :)
But do e-bikes have regenerative braking? I haven't seen that. I've been thinking that it would just be too heavy and clunky to be worth it.
Too heavy? You just run the motor in reverse which turns it into a generator and adds friction to do generative braking. There really isn't any added weight.
Bikes normally have freehubs, a ratchet on the cassette (sprockets) of the rear wheel, when you stop pedalling the bike freewheels, without that the pedals would keep turning.
This makes driving a motor from the wheel impossible without heavily modifying the normal bike mechanics. That's why regenerative braking on e bikes is rare.
Not if you have a hub motor. Those don't interact with the gear system at all.
Yup, which is also why they're really hard to pedal if the battery dies.
Only very cheap e-bikes have hub motors. They're not a good idea precisely because they don't interact with the gearing system. So you lose that functionality.
It's not worth losing access to gearing just to get regenerative braking because the amount of power being used isn't worth trying to recoup.
It needs a direct drive which is more weight than the other systems
Why would it need a direct drive? A mid drive can do the same thing they just don't usually since you'd need to gear for it. direct drives are the most efficient at regenerative braking but they aren't the only type.
Freewheel hub would prevent it.
You would need to put the freewheel between the motor and the pedals, and have an always-spinning chain/shaft
Could be done, perhaps, with significant added complexity (and hence maintenance). In practice it is not, to my knowledge there are no mid-mount regenerative system on the market. It is worth noting that mid-mounts are significantly more efficient than hub mount, enough so that even compared to hub mounts with regeneration, mid-mounts have more range for a given battery / wattage. The vast majority of hub mounts also do not implement regeneration.
You can find YouTube videos of people experimenting with flywheel-based regenerative braking. They're completely impractical but pretty funny to see.
Motors are generators when run inversely:
Motors = put in power to get rotational movement
Generators = put in rotational movement to get power
You already have the heaviest parts on the ebike - motor and battery, just need some capacitors and charging circuit board which are light and not too big.
Cheap electric bikes I've ridden with regen breaking slow you down quite a bit.
It's not difficult to get regenerative braking on a bike it's just difficult to get regenerative braking on a bike that's any good. Hub mounted motors are the least efficient type of motor because it's just directly driving the wheel at whatever speed it can output, with no access to gear ratios. E-bikes that forgo generative breaking in favour of a more efficient motor designs achieve better speeds for any given amount of power usage.
So yeah you can absolutely do it. But it's not a good idea for reasons that have nothing to do with the weight.
It's like 3-15% energy reclaimed, not efficient
Yes, but is it possible to pedal and use regen breaking to recharge the battery when stationary? It does work like that in my car (plug-in hybrid) but I don't know if e-bikes are the same way.
The traditional method of pedaling uphill less strenuously is to drop to a lower gear. You might go slower, but I'd bet even on existing e-bikes with pedal assist, this is something that's already pretty reasonable now days.
That's what gearing is for (you just go up the hill slower), but I can see the benefit to not being on the road.
Sure, but there are limits. One needs a certain amount of forward speed to maintain balance easily, and there's a maximum speed that can be reasonably pedaled. If the hill is steep enough then in my experience reducing the gearing enough to make pedaling not too strenuous runs into the other two limits. If an e-bike can have a low battery topped off before the hill starts, then pedal-assist (at least) would take care of the need to lower the gear while going up it.
If you need a minimum speed to maintain balance, how are you going to pedal while stationary?
Better to have active regeneration, where you pedal a bit harder on flats to top up the battery for hills.
Kickstand, holding a fence, etc. That active Regen thing sounds great, if I buy one of these I'll make sure it can do it.
Not true. One just needs to practice static balance. It's a great skill to have so everyone should learn how to do it.
Also you can use the lowest gear going almost a walking pace and climb up really steep hills. That's how we do it on MTBs. It also requires practice and good balance.
Ah, that would be a nice skill. I might even be better equipped for it now than when I was young because I've gotten into roller skating and improved my balance that way.
Gears
Incredible comment.
Nice to get a moment to pull out a classic
As someone who sucks at physics, I'm convinced that Trollface has proposed so many solutions around the internet to provide free energy, but the capitalists are conspiring to sabotage him, just as they did to N.Tesla.
The other one being to shine a light on a solar panel. For bonus points you include a mirror and a vampire.
I remember the one where he uses two magnets, and the one where he wraps his head with a bag and puts a plant inside it, so he can swim with infinite O2 supply.
honestly this probably works to some degree, just that you'll move at walking speed relative to the ground if you go up to the edge of space
This is satire… right? I hope it is
I'd go with second law of thermodynamics, but whatever.
The amount of emojis scream AI generated.
OR hear me out, AI was trained on these kind of posts. Emoji were overused in similar fashion before the AI bubble. Remember when crypto and NFT was all the rage? Crypto bros were all posting like this. And it worked on gullible people, so now AI does it too.
It's funny how everyone thinks they're AI detectives now.
LinkedIn has been shit posting goldmine lately.
I have never seen the Arabic language translation of this meme but I immediately understood it from having seen the English version.
I had this exact idea... when I was 7. That was before I was introduced to newtonian physics.
It's a good idea, even if it can be ruled out. That person should offer more ideas. All of those Newtonian physics people never seem to offer up ideas.
You were introduced to classical mechanics at age 8?
They could've heard of Newtonian physics at any point between when they had the idea and now
Sort of.
They can understand some basic concepts before you get into the math. Especially potential energy turning into heat, which children experience firsthand frequently. IMHO kids these days seem to understand energy more easily than we did; I think it's because of video games.
Looks like it could even be AI style with all the emojis.
Either way, thanks I hate it.
Yea I’m 99% sure it was drafted by AI
There have been idiots before AI. People should still receive
blamecredit for their idiot ideas, instead of blaming AI for every stupid post.Likely not only drafted with AI, but only pursued because he entered the idea into ChatGPT and asked "is this a good idea?," and uncritically took ChatGPT's enthusiastic support as vindication.
Perpetual motion machine aside, where tf is bro going that the range of an ebike isn't enough, but the speed is
The Future
Actually kind of like the idea of a pedal powered time machine. I feel like there's got to be some anime that does that.
DC's Flash has a threadmill, that's close enough
Tbf it wouldn't be a perpetual motion machine because batteries -- even rechargeable ones -- have a limited capacity that reduces over time because they are a chemical reaction, the components of which degrade over time.
are you stupid? just make the motion of the bike undegrade the chemistry. you clearly are not a mechanical engineering student
👉 motion revitalizes the reservoir of motion
#Innovation #EV #MechanicalEngineering
Lmfao you had me for a moment
As well as inevitable failure at the weakest friction point.
Tldr, thermodynamics
This guy apparently doesn’t understand the first and second laws of thermodynamics. However, in his defense, this is sorta how regenerative braking works, but with less complexity.
Most people don't. There is just no free lunch to ever be had.
That explains why we exist right now (for free)
A very, very unfunny joke.
Regenerative braking was my first thought.
It's impressive that he figured out how to create a post though, considering room temp iq (during the winter in a commie block apartment, in celsius)
Mechanical engineering student huh? Good to know he didn't attend class on day 1 of dynamics
This is a normal trajectory for college freshmen. Get introduced to a bunch of basic ideas. Spitball and try to see how you can apply them. Start running into all kinds of caveats and engineering hurdles. Go back to class. Bother the RA. Maybe actually learn more about what you're trying to accomplish. Become a better engineer.
Knowing you can't invent a perpetual motion machine is like high school level science, so being a first year college student isn't an excuse.
Hearing that you can't and understanding exactly why are two very different states of understanding.
One is simple recitation of a fact.
Yeah but you missed rule 1: Don't post your gobshite ideas on LinkedIn.
Not believing you can create a perpetual motion machine should practically be an entry requirement. If you think you can you need to go back and do high school science again.
Nah, engineering students often forget and design perpetual motion machines. Usually, they remember why that is stupid and impossible before they post it publicly where I can haunt them forever.
It should be a graduation requirement. It really should be...
Bro forgot to pay attention to thermodynamics.
I once had an exam question that began with the phrase "ignoring thermodynamic principles...". That question really threw me, it basically asked what would happen under XYZ situation if physics didn't exist. How the hell am I supposed to know that?
Wow, excessive emojis and em-dashes... Not ai at all
My LinkedIn feed is like 90+% AI at this point. I don't know why anyone bothers looking at the "content" on that website anymore. I only see it just incidentally on my way to the job listings and I am always shocked at how terrible it is
with uBlock Origin you can just filter the feed
I was about to say, could this post possibly have any more emojis? Although, from my knowledge of existing MLM hunbots I unfortunately already know the answer lol
Yeesh... the entire thing is so much secondhand embarrassment it makes me want to delete my entire profile just for the sake of it regardless of never using the actual site
Either he's lying about being a mechanical engineer or the barrier to entry to become a mechanical engineer is embarrassingly low.
It this guy seriously proposing a perpetual motion machine for the purposes of EV charging? Also not that it really matters but who the hell has range anxiety on an electric bicycle. You get 30 miles out of those things easily, what sort of bike rides is he doing where you have to recharge that more than once a month?
He should try recharging a solar panel with a light powered by the solar panel. Just achieving infinite power.
I've gone as far as 55 miles in one bike ride, and hope to do a full century ride someday. 30 miles is not at all out of the ordinary for bicyclists.
If I can do it after not riding my bike for a year, then so can you.
Thanks, I don't doubt it. Biggest issue is that I have significant anxiety about doing any riding after a really close call some years ago. A car was going something like 50 mph on a 35 limit street, and was inches from hitting me from behind. Technically it did hit, but only enough to barely whiff past my body, and put a small dent in my rear rack.
30 miles is laughably low. A single ride would drain it for me. To go to store it would take 10 miles, not counting anything else.
I recommend going to a closer store.
Why? For less convenient, choice, and worse prices?
A 10 mile round trip would probably take about 3 hours, it probably isn't as far as you think it is.
3 hours? How slow do you bike? I average 25 to 30mph on a non powered mountain bike. I could walk that in 3 hours.
30mph is incredible
Literally. Especially on a mountainbike averaging 50kmh is insane.
Probably own a speed pedelec. They average that top speed.
But then you could just buy an electric moped instead.
Says unpowered mountainbike in the post though. Can only imagine they meant 30kmh
I work 18 kilometres away from where I live, that takes me 45 minutes on my acoustic bike. That's just a little longer than 10 miles. The round trip is ~an hour and a half
Are you walking or cycling?
He's a student so he probably just doesn't know any better
I mean A middle school student should understand why this won't work, so not much of an excuse
Yeah you need to take basic physics in high school before even getting in to engineering school.
My distance to work is 12 km one way, so your battery would be empty afer two days...
16km for me and I'm not even leaving the city, this battery would last a day, not that I need it.
He's probably lying. While the bar is pretty low for entry level M.E.s, it's not quite that low yet.
As an old Toolmaker, I have made my share of intern wannabe MEs cry after crushing their idiot ideas. I swear, the older engineers would send those clowns to me just so I would beat them about the head and neck with a stick.
(I have a Daughter that has a PhD in ME. I warned her to turn down the free lobotomy offer upon finishing her degree. She listened and is now a happy and very, very smart Dr. of Engineering working with EV and HVAC systems)
Don't be so hard on him. He is still a student and got to learn.
Why not cut out the middle man and directly charge battery 2 with battery 1? Switch and repeat.
wow, you did not have to call out my subnautica in-cyclops power cell recharging stations for spare cyclops batteries like that
Newton? Never heard of him.
That's effectively what hybrid cars do.
Essentially regenerative braking. Should work, though the question is how coat effective.
Wrong question.
Right question: When the fully torqued spring inevitably fails, who is liable for the deaths of the rider and nearby pedestrians?
Wrong question. That one is answered with a EULA.
Right question: how often can we make that torque spring break, forcing the buyer to buy another one, without them realizing it's failure by design?
Wrong question.
Right question: How do we embed an LLM to decide when to break the spring so that we can score a 100B investment from OpenAI.
Wrong question.
Right question: What if we used a giant flywheel? That can't be dangerous, right?
Bahaha!! You got me! That's actually a really good one hahahahah!
F1 has been using this principle for years
That's just regenerative braking on a bike. Without batteries.
In theory that idea isn't actually bad although I suspect in practise the mechanism would be extremely complicated and would be liable to jamming it in opportune moments. That said doing this electronically is already a thing, although not really in e-bikes.
pretty sure hybrid cars have regenerative braking - the car uses the motion to recharge the battery when braking, going downhill, or coasting
Dynamo lights work off a similar principle. It extracts energy from pedaling or the wheels spinning to power lights on the bike. You can feel the drag and it's probably about 5w of power. Really not a whole lot. About the same energy you'd save from wearing smooth socks or cleaning the chain for some perspective.
The extra weight required to implement a solution like yours would probably rob the rider of any gains. But in a very theoretical sense it could work if the material weighed an insignificant amount.
Why flip a switch when you can just let the bike sense if it is going up or down hill?
Would make hilly terrain a much smoother ride.
Then again, if you do all that electrical, you already just have an electric bike. Which is even more versatile on flat ground.
With this many emojis and em dashes, he's probably engagement farming using llm content, regardless of the thermodynamics gaps in logic
This has to be a parody account right?
Either that, or he's not very smart, had a thought, poppet it into ChatGPT, and ChatGPT as it tends to do, affirmed his dumb idea, and he ended up asking it to make a Linkedin post for him on the idea.
I've seen similar stuff from students who think they've cracked how something works, only to be incredibly wrong, because they only know half of what they need to, but don't know enough to understand how little they know. It's part of the journey of getting sorta-good at something though.
A parody account... on LinkedIn?
I'm becoming increasingly more and more confused as to what this site's purpose is intended for... I think they lied to me in college lol
It's almost as if one object perpetually moves something that creates a form of motion perpetually to continuously move that first item. Like a continuous motion machine or perpetual movement apparatus. Something like that. I feel like my naming is close, though.
Seems like satire to me. Pretty funny too.
The Law of LinkedIn:
If you think it's satire, it's probably actually just a really stupid individual.
Techbros rediscovering old principles, a tale as old as....well, since the tech industry.
This guy is only telling us part of the truth. You actually need three batteries. The third battery is hooked up to a solar and wind generator. Only then can you achieve true energy independence.
don't forget to add quantum tunneling between the batteries for extra efficiency
got to also involve nft, blockchain and ai somehow
Make sure to invert the polarity of the dilithium matrix. That always seems to help.
So you're on your ebike, going 15mph. Using 140w or so. You're spending 15-20w on the drivetrain, and the remainder is entirely aerodynamic drag. You're putting 120-125w into making wind move. You're also losing 5-10 watts to the drive electronics and dashboard. So your total power use is 150w.
If you're going to recharge a battery. In the same time it takes to ride, you need to get at least 150w of power into another battery. Sadly, batteries don't actually "just cleanly charge" there are some losses, but since we're going to take an hour to charge it, lets call it 5%. So to fill up that battery we need 157watts of input power.
Your bike, moving at a steady speed, is absorbing 150w of power. If we want another 155w of power, where is that going to come from? If we take it from.. say.. the front wheel, we are now absorbing another 155w of power. So to maintain the same speed, we now need to push the bike along with 305w of power. And.. now we need a bike that makes 305w of power, to go the same speed we were going with 150w. .... And we're only generating 155w.
There is no free lunch. If you're doing work, you need to get that power from somewhere.
Counterpoint:
Hills exist, go down them.
Like, the whole point of these things, at lesst as I see them, is that you get that free lunch on the way down a hill, then when going up a hill, well yeah, you still aren't gonna like, be 1:1 be able to power right back up it, but it will be easier going up that hill than if you did not have your free energy lunch on the way down.
This then results in you not needing to expend as many literal calories going up a hill, so now, you don't need as much food to recharge after a ride, thus you do actually on net come away with at least a portion of a 'free lunch', in that you don't need as much food.
But yes, I will give you that... the overall weight added to the bike from the batteries would have to be in a manageable range, so that the uphill assistance is not just entirely used on uh, pulling its own weight.
The problem with "go down a hill" is that the LinkedIn idiot wants to use the power of one motor to generate power in the other. Regenerative braking only needs one motor and it acts as a generator when braking.
I mean... you can do regenerative breaking in a hyrbid car, where the main LiON battery is also charged from the ICE engine.
I had a hybrid Prius C that worked this way.
Roll it down a hill, far enough, in the right mode?
Recharges the main hybrid battery.
And then, you can also put it into a low power, EV only drive mode. Can't do inclines or go fast, but you can get up to about 20mph on flat terrain.
Like, I've done that at least once, as a kind of makeshift jumpstart sort of thing.
Presumably, it may be possible to scale such a system down to a bicycle, or maybe moped or motorcycle.
And the LinkedIn guy specifies that there are two different batteries, which are capable of transfering power between each other.
So their system is regen braking -> bat 2 -> transfer -> bat 1 -> drive motor.
Personally, I don't even see why you need two distinct batteries, just have a powerstation type thing with a some software that regulates power uptake and output intelligently.
Regenerative braking is not the problem. Thats been solved. The LinkedIn user is trying to invent perpetual motion
They're not actually describing that, explicitly.
What he's said can be interpreted that way, if you add some words he didn't say into this post...
... but he didn't actually say that.
A 'continuous self charging loop' is not the same thing as... that, but which also generates infinite energy or is somehow overunity, over 100% efficient.
That just means there is a continuous loop by which energy can flow from the regen braking to the motor.
It doesn't mean that energy is always flowing through that loop... it just means that some amount of energy could be.
It doesn't mean that power coming into the motor or batteries always exceeds the maximum power consumed by the motor.
(that would infact be very bad and cause the batteries to explode/burst into flame at some point if we're talking about LiON)
Continuous loop is... an actual electrical engineering term, and its actual meaning is basically as I have just described.
Now sure, if this actual LinkedIn post is rather recent, well its rather cute that he seems to think he is the first person to come up with this idea...
But, it is also cute that the vast majority of commenters in this thread are suggestible (by way of being mentally framed with a narrative by the comm this is posted in and the post title) and have either poor reading comprehension, or just didn't bother to actually read what this 'lunatic' wrote... and are acting like they're better engineers than this guy, that he's bonkers... when in actuality, they're all showing their own asses unintentionally, proving that they don't know basic electrical engineering terms.
For this guy to have actually been trying to describe a perpetual energy devicre, he would have had to say something like 'a continuous- ly self charging loop that is over 100% efficient'.
He even specifically said his goal was to reduce the need for external charging.
Not eliminate, which would imply he thought it was overunity, but no, just reduce, which... would indeed be the result if his system worked and granted an extra 10% or 20% to overall EV bicycle range.
Yeah, in engineering, as well as language, precision and small details can make for large differences in the end result.
You do get about 5-10% more range with regen on an ebike, the downside is it needs to be a hub motor which sucks at climbing hills, and one with no internal clutch which means pedaling with the motor off wastes a ton of energy.
So like regenerative breaking for e-bikes? Except that such a thing already exists.
Apparently regenerative breaking efficiency in bikes is rather limited (small motors / generators, high friction). It still increases the range a fair bit (enough to be a better investment than bigger batteries), but efficiency is still not as high in bikes as in bigger vehicles which can drive more kinetic energy into bigger generators with better individual wheel control
Some paper says ~25% extra range in bikes at the high end vs ~50% energy savings in Japanese trains. Different units for those numbers, but you can infer that trains has much more efficient regenerative breaking because that number indicate a doubled range for the same amount of energy used.
I have a very high end e-bike (because I'm bad with money) and it doesn't have regenerative braking so I don't think it is a thing.
I know regenerative braking is a thing but it just doesn't seem to be on ebikes all that much if at all.
A mechanical engineering student that doesn't know the law of energy conservation?
Does he have a fundme or patreon page? I think it's worth supporting his research if it can be applied to cars and trains one day.
If somebody is an airplane engineer, is it possible to do something like that with planes? It would be great if planes could become environmentally friendly with such technologies.
There was actually a prototype environmentally friendly airplane designed and tested back in 2000 during a genocide in Yorkshire that I feel like isn't talked about enough. The plane, using bicycle technology, was successful in transporting all of the local populace to safe territory with the help of a veteran Royal Air Force member and an American entertainer posing as a flight specialist. Really an incredible story and there's still footage of the flight. but I don't know the status of the airplane today.
Thank you for the levity.
Hello, I am the owner of a large investment fund and I am willing to offer 1 billion dollars to develop this young man’s technology
They are already trying to EV airplanes.
Is this serious or a joke? Regenerative braking and other energy recovery methods have been standard on electrified vehicles for decades. Electric planes do exist, but the problem is that the mass to thrust ratio for electric motors is worse than jet engines. Most successful ones are pretty small and light.
I think you don't fully grasp the genious, magnitude and potential of Aryan Bhambure's invention. A continuous self-charging loop would essentially eliminate the time wasted on charging batteries. There would be no limit on the range of a car.
That's even more interesting for planes, given that a transfer is possible. As others have mentioned, the technology is heavy, which could make it unsuitable for planes. But if those limitations can be overcome, direct flights between all places of earth become possible. I think that's an advancement to humanity that's worth our support.
Unironically, I would enjoy a bike that I could pedal at a constant speed, charging the battery all the while. Give me a display that indicates my pedaling speed so that I can tailor my exercise and you’ve created a moving stationary bike. I hate having to stop at lights and whatnot, so a rotation-based stabilizer would be nice at speeds below 10 km/h as I pedal the equivalent of 30.
Really, it’s just unfortunate that the engineering doesn't work out for momentum->chemical energy unless you’re biking at a professional level and willing to cruise slowly or charging the battery at home. Bleh
Yeah, same, I like this idea.
If your actually mobile bike can also be used as a makeshift generator, to feed into a home backup battery?
Yeah maybe not huge levels of appeal there, but it is a neat utility feature.
Maybe I've played too many zombie survival games with base building... or, maybe I am aware of the shockingly shitty state of the US power grid.
Also:
If you have a bike, and battery/powerstation like that?
That leads to a potentially amazingly ironic situation where you effectively jump start a dead ICE car ultimately from a fucking bicycle, if you can hook your battery/transformer/power station thing to charge a portable car battery jump starter.
Honestly this would make a great video idea for Tom Stanton.
I love it, and it reminds me of James May talking about using launch control at a zebra crossing
I am not well versed in modern electric bikes. Do they offer regenerative braking yet?
Yes but they do not offer regenerative... Accelerating
My e-bike dosen't have it and it's sounds pretty complex to add efficiently on a bike. It's just take like 5 hours to charge in a normal output. And every corporate building have outputs for e-bike so I can charge while working.
It's very doable if you put the motor inside the back wheel. Because then it's very easy to run the motor as a generator.
At this point just cut the middle man and have battery 1 directly charge battery 2, then reverse it when it's done. Same results with way less hassle
You could harvest energy from going down hills and braking, but that’s probably not work the weight.
For each second of using regenerative braking, you can accelerate for 0.7 seconds.
But how much do you actually brake when riding a bicycle? That's completely neglectable (at least for me).
Electric cars already do this and I'm sure there are some smaller electronic mobility devices that also do regenerative braking. It's not exactly a new concept.
What added weight? If there already is an electric motor on the bike you can just use that as a generator during braking or coasting down a hill. That’s what EVs already do.
Unrelated, but the pedaling cadence people have on ebikes bothers me. I'm always seeing folks in a high gear slowly pedaling. I'm like dude you're sacrificing watts! Pedal faster on a lower gear, you'll use the same energy but go faster.
You get into the habit of just ignoring the gears because it doesn't seem to make any real difference. Sure been in a lower gear is more efficient but it doesn't feel any different so you don't think about it.
I thought it was the other way around, where doing the higher force version results in higher efficiency, so you use more energy to achieve the same effect (when you use the lower gear and pedal more). It's easier to generate force but takes more energy to apply that force over the same diatance (because the converted distance you're applying it to on your end is longer).
The optimal method for range is basically PWM (pedal then pause and repeat) at the highest output that you can sustain (up to a limit, where both increased losses from the speed during bursts and from your muscles becomes too high)
Spinning in low gear uses the human body's capabilities more efficiently. Whether more or less distance is spun is less important because it is so much easier to pedal low gear/high cadence. It's the difference between jogging and sprinting. High cadence/low gear keeps it a mainly cardiorespiratory endeavor while low cadence/high gear is just your quads vs your ability to suffer. You can look at the legs of distance (tour de France) vs sprint (track) cyclists to see the difference in body composition from each approach. I'm not arguing with your reasoning. I've only ever measured watts not watt/hours.
Hmm, when I go out for a ride my muscles always feel better if I'm keeping my cadence high vs grinding in a high gear. Like muscles don't act the same way a motor does. And if I'm on an ebikes I want to get the most of what my muscles are doing.
But maybe grinding in a higher gear is better for endurance, IDK?
There was this browser game (on the BBC website IIRC) with a Wallace and Gromit theme, in which you build stuff.
It had a level in which you make a vehicle-ish contraption and see how far it goes ^[or more like whatever contraption you can make to get the dummy to go as far as possible. Could even be a cannon, launching the dummy.]. I managed to setup a motor and generator in such a way that it effectively increased the vehicle's range by quite a bit.
I don't remember well enough now, but I think the generator didn't give as much resistance as the energy it was creating.
🤦♂️
I had this idea 30 years ago lol. Bicycling in headwinds in windy and flat Denmark gives you a lot of time to think of dumb shit like that, like what if I put small wind turbines on my bike which generated electricity to give me a boost?
We've had windmills as part of the landscape here for a long time after all, so it wasn't exactly rocket science to think that one up.
Wind being an outside source of energy can actually make this work. As long as the wind is blowing, not just your own motion making it feel windy.
Actually, that jostled my memory a bit, I just remembered that I saw a veritasium video about this a month ago or so, while it wasn't about generating electricity and using that for a motor, but just straight up wind to mechanical energy.
Or you know, a sail.
http://www.britishlandsailing.org.uk/
He must quickly Patent it and get venture capital funding for this brilliant idea!
Nobody will even consider listening to a pitch to schedule a phone call to listen to an elevator pitch for consideration for a short phone interview to be considered for a meeting to speak with the board, unless it includes AI for some useless reason.
So add AI.
I mean... regenerative braking is a thing.
My hybrid Prius C had this, and yes, you actually can build up some useful amount of charge from just rolling down a decently large or long hill, and you can also run the car on pure EV mode, though you're probably not gonna top 20 mph on a flat road.
Obviously this does not create an over unity situation or perpetual motion machine, but, if this guy can figure out a way to put a regenerative braking type device onto an E-Bike, or maybe motorcycle/moped, in a way that isn't stupid expensive...
That could increase overall range, and I think it would be neat.
Though I... don't really know why you wouldn't just use one battery for the whole system, just have a modulation/regulation system for it.
It's not free energy, but there's at least one bike called the Pi-Pop that works this way in order to spread the energy demand from hills across more distance for the rider. It's an electric bike you can't plug in, it only charges from moving
There is one particular mine, I forget where, and they extract ore at the top of the hill and carry it down in electric trucks that gather more energy on the downhill run than they need to get back to the top when empty, so they never need to be charged.
That's awesome, reminds me of a common historic setup where cable cars were used kinda like that (heavier on the way down)
I found an article talking about it- apparently it's just one experimental truck in Switzerland that actually generates 10kWh per trip.
Not for nothing, but I just posted from the future!
Oh god, lemmy has figured what Google Stadia couldn't!
No, no, I am never going to forget how insane of them it was to claim they could deliver 'negative latency'.
God fucking damnit, I am apparently still mad that happened.
Oh, yeah, I had that issue for a while. I think my computer clock was differing somehow from the server clock, and I was always a few minutes in the future.
Fun fact, similar tech is already widely used, in gas cars too, that's how the battery is charged :)
I cannot facepalm any harder. Dude that's some 8yr old question shit
Yes, many electric bicycles power themselves while going down hills or costing. As for the other idea that you could recharge them just by pedaling ... That exists already. Almost nobody wants it because it's easier to plug your bicycle in. The point of the electric bicycle is to do less work, not to do more. Otherwise you would get a regular bicycle because it weighs less.
Regen braking exists, and everyone does want it, because it gives free power when you hit the brakes. The reason nobody adds it is because up until recently, you could only have coasting or regen braking, and not having to pedal literally all the time is just far more important for bikes. There's a recent tech, freegen? Called something like that, it lets you have both regen braking and coasting,
If he removes battery 2 and charge directly battery 1 (as it's pointless either way and adds weight) maybe he can figure out what's wrong.
Or it's ai slop.
Someone has been spending too much time on ChatGPT.
I have a better one: charge from temperature gradients as it moves through new areas.
Has to be a joke
Do most e-bikes not charge from the pedals? Combine that with regenerative coasting/braking, and this isn't really that dumb. Like yeah, obviously thermodynamics, but an E-bike with pedal charging isn't a closed system.
Regenerative braking is not worth it on bikes... it's worth it on cars because you are slowing down over one and a half tons of weight and going much faster so there is serious amount of energy to be recovered
You’d basically need electronic braking for this to work. Which should be theoretically possible since we already have electronic gear shifts. Would be tricky to get the feel right in the transition between motor to friction.
The pedals seemed like the bigger contributor, I just added the other for a few percent.
If I'm riding an electric bike, it's to make pedaling easier. Why would I want an electric bike that's harder to pedal?
If you extract enough energy from pedaling to charge a battery while also travelling, you'll definitely end up using more power than less. Which absolutely defeats the purpose.
All these "smart" ideas would already be implemented if they were actually clever and deployable. The reason no one does it is because physics doesn't work that way.
I've built two eBikes and can confirm that they do not.
WOOOOOOOOOOOOOOOOOOOOOOOO!
Aw man, Lemmy finally got a LinkedInLunatics instance? How long has this been here? That was like the last thread I've been hanging onto with reddit. Finally, this place feels like a genuine alternative 🎉
Welcome to the fediverse's LinkedInLunatics, my friend!
The community (which isn't an instance!) has been there for a couple of years already: https://sh.itjust.works/post/27701
If you haven't come across it before there is the Lemmy Explorer tool (with options for Piefed and Mbin as well): https://lemmyverse.net/communities
I don't claim to be an engineering student, why is this a bad idea? Wouldn't he just put a "collector" of energy (like a wind turbine) on the wheels?
It would wash out. Any energy collected would be at the cost of resistance. So add fans to add wind resistance. You could collect energy from coasting and braking, but that's just tech we've been using for years in cars, and it comes at the cost of movement. It actively slows you down because the energy has to come from somewhere. And since energy conversion is hardly one-to-one (loss to heat, etc), storing it into a battery and then pulling it out again means you won't gain as much as you lose.
Energy cannot be created or destroyed. If you are generating energy, you're taking it from somewhere, and on a bike, it's from your forward movement.
Okay, I get that, but wouldn't the collection be a separate system? The energy is being created by the battery, then a separate system collects the energy.
Because its all the same energy, and the contraption just slows down.
But if you're on a hill, you'll go much faster, thus storing more energy.
Yes, you could collect energy while coasting down a hill, but it would slow you down. Which is fine if you want to slow down; this is the basis for regenerative braking. You might be thinking that a pinwheel spins like crazy in the wind, and that's just free energy. But a pinwheel doesn't store anything. To store energy, you need to add resistance, and the more you add, the more energy you collect and the harder it is to spin the wheel.
So at the end of the day, you've got a fan at the front of the bike that is either spinning quickly with little resistance and storing little energy or one that is spinning slowly and collecting more. And the slower it spins, the more pushback there is against your forward movement.
Despite there being two batteries, this is still a single system which uses energy to propel the bike forward and collects energy by preventing the bike from moving forward. They offset. The only way to have the energy to propel the bike is by introducing energy from another source (not related to the movement of the bike) such as a battery charged ahead of time or calorie loss of the rider (active pedaling).
Thank you for this detailed explanation. I appreciate it. That's exactly what I was thinking about, a pinwheel.
Now you're introducing potential energy (a hill), which will be used up (or rather be fully converted to kinetic energy) once you reach the bottom, and you're going to need the same or more energy to go up that same hill again (depending if you take resistance into account).
We already have tech for capturing kinetic energy for later in the same battery used for driving called "Regenerative braking" (cuz' the motor is used as a generator in place of brakes, and you'll need to drive said generator by capturing/braking some of your kinetic energy/forward motion).
EDIT: In other words: You could just start on a really high hill and you'd be able to use the weight of the bike and yourself as a "battery", never needing any actual battery/motors/wiring/etc.
Imagine it like this, you have two glasses of water, labeled “speed” and “chemical.” You can only transfer water between glasses. And messily. It’s a sum of water, a specific weight of water between the two glasses that you own. In placing the water elsewhere, you haven’t done much besides lose a portion in the transfer. You can absolutely do what you’ve said! It will, unfortunately, just be a transfer from the speed to the chemical glass. You’d just lose a bit in the transfer.
What happens to an object in motion when you collect its kinetic energy?
Okay, I admittedly know nothing about this, so bear with my ignorance. Aren't you just moving gears? It would generally be like an auto engine where you have all of these explosions that push gears. You're just moving the gear in one direction as a click, click, click.
Turn off the engine of your car, does it keep rolling at the same speed forever?
Where are you going to get that power on a bike? Your legs. Do you really want to peddle away to charge a battery at SIGNIFICANTLY reduced efficiency, then with even more loss of efficiency discharge the battery into an electric motor? Or do you just want your energy going directly to the wheels?
The person in the post is trying to come up with an infinite source of energy which is not possible.
All of these points are well taken, but I didn't understand it as infinite, but more like to get you where you're going.
On an e-bike you would be losing significant portion of energy from propelling the bike, friction, air drag and heat loss. You might be able to put a small amount of energy back in from pedaling, going down hills or even braking, but certainly not enough to make it perpetual.
Perpetual motion machine are physically impossible based on our current understanding of physics. Many, many people have attempted to create them, but they all fail from the reaaons above.
So last question, I promise.
A wind turbine collects the energy of the wind through movement. A gear can give more "force," so I'm assuming more movement of something. If you have 2 different systems, one that collects the movement, or more "force," and one that is making the bike move, why wouldn't that be close to collecting as much as you put in. You'd have to charge occasionally, but not all of the time.
With the bike, the battery (and pedaling) is the source of your net energy output. Losses from friction to the ground and air drag will be the most significant net consumers of the energy. It doesn't matter how the rest of that energy is moved around within the system(s) of the bike.
Ultimately, what determines the distance you travel is the capacity of the battery and what external environmental factors affect the bike and by how much. Biking at 3m/s will have less air drag than 10m/s. Friction will be affected by the surfaces you go over, with something like mud taking more energy compared to something smooth like smooth concrete.
No, they are not separate systems and you will always have significant losses of energy to friction.
Gears change how energy is transferred, but more gears means more energy loss. Always.
Conservation of energy, basically it's not that it wouldn't work "at all" or appear to anyway but that it wouldn't work as desired. You can't recapture the power used to propel the bike because it's being used to propel the bike. Adding a collector increases the power needed to turn the wheels and basically makes the drive battery's job harder, so it runs less efficiently and runs out faster, battery 2 does charge and can be run from, but in the end you end up with less range due to the stacking inefficiency and energy leakage. The closest functional system to what they are talking about would be a breaking system like electric cars use.
Thank you for taking the time and patience, this explains it for me in a way that makes sense.
If you are drawing energy out of a system them that amount of energy is removed from the system. A freespinning gear won't generate electricity. It has to be pushed, which requires more energy from the power source, and is always a net loss because of friction.
That is before the added weight of the additional batteries.
So trying to get energy back from a moving cycle will result in a less efficient bike.
Alternators exist on a car, why not on a bike?
Alternators don't exist on electric cars. The closest is regenerative breaking, which powers the car by slowing the car down.
So we just need to put something on the bike to power the alternator…I know, an engine! Why has nobody thought of this before?!
Oh shit you solved it!
I was being sarcasmic.
🥵
You can power lights or a phone charger with a dynamo connected to the wheel and minimally noticeable drag/resistance. You can recharge a drivetrain with regenerative braking which requires high end motors to use the motor like a dynamo
Yes, you can collect some of the kinetic energy and put it back into a battery with regen braking, but most of the energy put into such a system will be lost to heat/friction, drag, drivetrain inefficiencies, battery inefficiencies, recovery inefficiencies, etc.
In the lunatic post, he's not talking about regen braking. He's talking about using the same system that moves the vehicle to simulatneously charge a battery. Which means you're taking some of the energy which would normally move the vehicle and shunting it into a recharging "circuit" - which introduces even more losses.
The end result would be a machine that is less efficient.
Just assume a perfect world, and we won't loose any energy!
....... Though we won't gain any either. -,-'
Regen braking is on every single electric car. But it's incredibly inefficient and costs a lot of money to add it.
On a 60k car? Yeah it's worth it. On an $500 ebike? No, not at all.
It's a bad idea because he's essentially talking about a perpetual motion machine.
That makes sense, except the collection of the energy can be less than the energy expended, like an automobile or wind turbine. Then it could be a perpetual machine.
It would be like this:
Energy in => convert to a gear that makes it way more energy => store energy, repeat.
I must be missing something.
Gearing doesn't make more energy output than the energy put in.
The collection will always be less than the energy it takes to generate it. There no magical gear or trick to change that.
nah, see, a gear is basically just a fancy pully. it can make it easier to pedal up a hill, but only by making you have to pedal many more times to do so. each turn of the crank arms takes less force, but you have to do it many more times. it isn't actually reducing the energy requirement, and it isn't multiplying your energy input.
what you're describing here would be some kind of magic.
It could be an OK idea that just wasn't explained right. Maybe he just wants regen braking but with one wheel for charging and the other wheel + separate battery for power at any given time. Energy would come from pedalling and hills. None of that was explained though
Maybe you can join his team!
But I can forgive a non engineering student… its impossible.
Physics's older brother gonna be looking for this guy.
so, obvious reasons why this cannot work.
Is there anyway to like, siphon off the energy though? Like say, you pedaling produces 600kJ/hr. You have 400kJ/hr going into the bike to produce motion, but then 200kJ/hr goes into a battery. You'd move slower but generate stored potential energy.
I'm not really sure why you would want this, other than the concept of a self-charging electric bike, but on paper it sounds possible?
Yeah, it's called a dynamo, used for decades for powering headlamps on bikes before small batteries and LED lights. Still, the energy generated is pretty small.
You would need to output far more than twice the energy that you would get out of it and the effort to pedal would be significantly increased as you would have additional weight to the bike on top of whatever it was drawing.
Taking 1/3 if your pedal power would be like trying to bike through deep mud just to have a small boost later.
A normal bike drivetrain is around 95% efficient, which is more efficient than the Regen circuitry you could get in such a form factor. Therefore it makes more sense to use pedal power for direct propulsion since that will directly reduce battery more efficiently than using it for charging.
This is different than a series hybrid because car drivetrains are very inefficient compared to a bicycle.
It would only make the bike slower and have less range.
I see a lot of people clowning on this guy but is it possible that something like this could come in handy for commutes with elevation changes?
Coast to work and charge the battery, use pedal assist on the way home uphill.
Seems too niche to sell a bike for this, though.
That's how regenerative hybrids work, IDK if a bike has enough mass though.
It does. Ebikes with regen brakes exist
I had one, and it was shit for regen braking, but also terrifying. It was a dual 1kw motor (front and back wheels both powered) bike with a car battery sized LiFePO4 battery bolted over the back wheel. Incredibly top heavy, overpowered such that the front wheel would spin on the road at takeoff, and the regenerative braking was a fixed amount of deceleration. Meaning it would put, say, 100 Newton's of torque consistently when triggered. Want to stop from 50km/hr to zero in 10m? Too bad, this bike does it in 25m.
Want to apply just a little bit of braking? Too bad, these brakes are Boolean and they are either on or off.
I believe it was a homebrew import, I bought it off a guy who inherited it after his housemate died (not from the bike)
For context, the max legal motor size here is 250 watts (or 1/8th the power of this bike)
That’s not really how regenerative hybrids work. Turning linear motion into stored energy produces drag, aka braking, so when you hit the brakes, why not store some of that energy that would otherwise just be lost as heat in the brake pads. They’re not just finding extra energy to store for later while you travel downhill unless you have cruise control on (which is to say, unless the car is braking).
In a hybrid corolla, rolling down a hill without pressing the accelerator or breaks will regenerate the battery. Meaning the default is to always try to regenerate at least some energy and produce at least some drag. Letting go of the accelerator at some speed on a hybrid will slow the car to a halt sooner than a non hybrid would.
Well, I knew I’d leave too many loose ends explaining something before bed.
Not quite.
When you coast in a car with an internal combustion engine, you go further when you’re in neutral. Why? Engine braking. When you take your foot fully off the pedal, you restrict airflow to the engine and create a partial vacuum that the cylinders have to work against.
I’m not saying to coast in neutral for higher fuel efficiency. It’s quite the opposite with modern engines that cut off fuel injection when it’s not needed while in gear—and it can lead to increased wear and tear on the engine as well as your brakes fading on long descents. But now you have me covering my ass on every little point, ha. You could look up hypermiling and learn about more efficient driving techniques that way!
Now obviously hybrids have traditional internal combustion engines on board that behave the way we’ve just described. The engineers have also added a level of regenerative braking that is variably applied, even when the engine is not on, so that you scrub speed at a consistent pace. Without this, descending with the engine on or off would feel drastically different, and the car wouldn’t behave as expected at all times. It’s similar to how engineers for fully electric cars have added the “crawl” mode that makes a car idle forward when the brakes are off, even though there is no actual “idle” occurring. It makes the car handle the way you expect it to, and that makes you safer.
It is nice to recapture some energy that is used during the braking process. But only if you need to brake. Otherwise, you’re stealing energy you could be using right now and turning into less energy for later. The process of converting energy into various forms is inefficient, so you will always end up with less than you started, and the more conversions you do the more you lose. Potential gravitational energy to kinetic motion energy is more efficient than potential gravitational>potential chemical>kinetic motion, plus that last step is oversimplified because having the chemical energy turn a driveshaft is actually another kinetic energy conversion compared to gravity turning the wheels directly.
Thus e-bikes could benefit from regenerative braking if the system is efficient enough to overcome the loss of efficiency it introduces via weight and drag, but not from the constant low level capture of energy that would be better used now. Because you don’t get to fuel up an e-bike when the tank’s nearly empty—any toll you pay in inefficiency comes outta your legs and your lungs.
I am not an expert and I am sure I glossed over some nuances.
I'm not sure I get your point. What do you disagree with?
My point was hybrid regen is always on (unless accelerating), if it wasn't, the car would basically coast in neutral. I'm pretty sure hybrid car designers did the math and examined use cases to discover its more beneficial to recover some energy and not coast as much vs coast as much as possible and ONLY regen when breaking. Lightly breaking applies more regen force. Or are you saying they do this for the feeling only and regen is a byproduct.. if it even matters?
I'm not certain, but I'd say applying a little drag to regen on an ebike going downhill will be more beneficial than allowing the riders to go as fast as possible downhill. They could still turn it off, just like I can put a hybrid car in neutral and skip the drag, but why would I do that?
My point is exactly what I wrote! I know it’s a lot, I overcompensated.
Yes. I said it’s designed this way to feel like a normal car. But it’s a very elegant solution! Far better to do it that way and re-capture some of the energy than let it leave the system, like heat from brake pads.
That “drag” is braking!
Like letting go of the brake lever! Far simpler than adding a new always-on brake that you have to manage separately.
Because sometimes you want to go full speed down a hill because it’s the most efficient way of moving forward! If you slow down, you have to pedal more later. If you slow down and save some of the energy, you still have to pedal more later, because you can’t save all of the energy from the hill, you can only save part of the energy.
There’s a maximum speed you feel comfortable going on steeper descents, and you manually brake to manage it. That’s the only time regen makes sense on a bike.
Also, because we’re not talking about drag that only exists on the hill. This system exists at all times in a hybrid, and if you implement it on a bike, you’ll be coasting less on flat ground too any time you stop pedaling! Why would we want that? Would you brake in a hybrid when you’re on flat ground to “save it for later”? No! Braking, and engine braking, slow you down.
Not really, even in this hypothetically perfect scenario. Either the hill isn’t steep enough to generate any real excess energy from rolling down it (too much drag and you’ll stop rolling) or it’s steep enough that what you collect is offset by how much energy the ride home requires. The more potential energy you save for later, the slower you’re traveling now. And you can never cross the threshold to where it’s helpful. You’re trying to steal energy from a closed loop. It’s the “bowling ball dropped from face level” problem all over again. It can never get enough potential energy from its trip away to come all the way back.
Storing pedaled energy is pointless too.
Let’s say one regular old pedal rotation propels you 10 feet.
Let’s instead store 20% of that energy for later. You now only travel 8 feet.
While we’re converting that energy, we lose a quarter of it due to inefficiencies in the process. So now we’ve traveled 8 feet and stored 1.5 potential feet.
Pedal 1000 times. We go 8000 feet and store 1500 potential feet. Stop pedaling, turn on battery support, we go 1500 feet, we get 9500 total. 500 less than an unmodified bike. That’s excluding additional system inefficiencies like the added weight of the modifications and the mechanical efficiency of the pedal assist. It’s more efficient to just pedal.
Too much extra weight and resistance compared to the bike and driver for too less benefit. It works fine on a 2 ton box though, despite having two extra wheels.
Hmm, nice exercise in how wasteful cars really are.
or get a better battery since ur saving a lot of weight by not doing any of this. My research idea is not doing his.
It's almost like, it regenerates its energy
So an alternator?
No.
An alternator draws energy from the engine spinning but the draw uses more energy than the alternator puts out. It is a conversation system from mechanical to electric power.
The device being described in the image is an alternator: a device that captures energy from the movement of the machine.
I think everyone on this thread understands that alternators do not overcome entropy and that there is no infinite energy, but that’s besides the point.