Esk8 alternator/ Onboard generator

Hey guys I was wondering what some of you think about the possibility of creating an alternator or generator to charge our batteries while riding. In doing some research I found this:

Let me know if you guys think this concept can somehow work. I feel like if we could even give our ride 30% more distance, it would be a worthwhile addition. What do you guys think?

Well the vesc offers regenerative braking so if you break the motors are used as a generator and give some power back to the battery

I dont realy know how that product works but if it is just a turning generator it wouldnt give something extra because by the laws of physics you cant have a perpetuum mobile.

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Yeah but regen gives back seemingly very little. I’m not thinking of reproducing the same amount of energy spent, just sending the battery some energy while it’s exhausting some. Wouldn’t this effectively give more distance? Although not infinite.

Also, if you had two battery connections onboard, wouldn’t you be able to simply switch between a set of batteries “in use” and another set being charged.

Btw, I am by no means an electrical engineer, and that may be very obvious, please go easy on me if I seem dumb. I’m attempting to learn via poor mans education. Lol.

You are never going to truly get back the same amount of energy. You will loose a good amount through heat with something like this.

I think with the range newer batteries can give us, there’s really not a huge point (unless science of course) to start putting these on our boards. Tech needs to catch up with that type of stuff before its truly efficient.


Yes! Science, relative to experiment, to create better tech is exactly my goal.

Necessity is the mother of invention my friend.

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I love that saying!

Yea, that thing is gonna need to get way more powerful to be able to truly make a difference. 4.8v DC and 500ma? (I think thats what I read)

It may be enough to power some lights or something like that.

Yeah, but it also says you can have them make it capable of 13.xx volts, I was just thinking and researching and thought that generator might spark an idea for a concept that might benefit esk8.

Alternatively I was thinking about a hollow front axel with a ring and pinion gear, the pinion shaft could come out behind the front truck and turn a belt driven super small alternator.

I have no idea if this would even be efficient but I’m trying to put it out there to see if one of the electrical geniuses can create a forever battery for us.

Converting chemical energy to electrical, as is done in a battery, is very efficient. Converting from mechanical energy to electrical or vise vesa with a motor, as this thing does, isn’t as efficient but more important this passively gotten energy you’d get using this would be a loss of course and not free and this device creates some drag. You’d be more efficient just running electrical stuff straight from the battery. In a case where you’d want to slow down, then the conversion this thing does would be a benefit but the regen brakes are likely more efficient If looking for a source of free energy whilst riding. …the heat of the motor could be converted to electrical energy or the flexing of the deck and there’s electronic gizmos that do that conversion and would be with no net loss. The heat from the motor is lost energy anyway so you’d be making a more efficient system

I forget the name of the device that creates electricity due to the different temp but they’re built already and just have to mount it on the motor somehow or the mount and wait till the motor gets hot then sit back and reap the rewards.


That is a very interesting idea! I want to talk more about this but have to head to work. Thank you for the advice and the food for thought! @Hummie

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Unfortunately thermo transfer is wildly inefficient due to the natural insulation of air. What do you do for a living @hummie? This is twice now you have provided specific knowledge in a field not many know. Thermo electric generation or the seebeck effect is what you are referencing.

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O shit at three times I’m in trouble. I’m a sub teacher

Wonder how much energy could be gotten back from a well placed one of these. But with as little air between the plates as possible.

Or a pezio (forget how u say or spell it) …one of those bending quartz things, would do. At least you could catch that energy while riding n not have to wait till after already hot.

Yeah, the skateboard already does:

Chemical energy → mechanical energy Mechanical energy → chemical energy

About as efficiently as you can. If you want to do something different to improve and add range you need to switch the source and/or the storage mechanism as hummie mentioned. For instance a flywheel that you spin up on braking and store mechanical energy as mechanical energy. There’s some cars that do this. Something that injects water into hot motors and powers a turbine with the resulting steam similar to turbo charger. Ultimately the biggest place to recover lost energy is heat, but heat is one of the lowest quality energy sources so you won’t see much gains trying to recapture it and the mechanisms will be pretty complex.

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This thing is just cool

But want an ethanol one

I’m looking forward to taxi’ing on neighbors golf carts when my unity arrives. It’ll be great to be going 25 mph around the park while charging my battery. @Deodand, do you/the unity have preference over discharge and charge BMS vs discharge only? Someone mentioned that a discharge only bms can’t handle brake regen but I don’t buy it. Can you set me straight?

If you have the money and space in your build charge/discharge is ultimately safer (if it’s a quality bms). Problem is the bmses aren’t always designed with ekate in mind, so certain scenarios can cause the board to cut power on you which is a potential safety issue.

The unity was designed with charge only bypassed bms in mind. I prefer the simplicity of such a setup, but you just have to be careful to check your cell balance from time to time and make sure your charger is doing it’s job. This is true in either case but a discharge bms should cut power on you if the pack is out of balance badly where’s charge only won’t.

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Thank you for the clear and prompt response. Can’t wait to get my unity Thursday :grin:

Boo!! Mine is due Friday. No fair! I bought mine first, isn’t that how it’s suppose to work? I’m gonna complain for a couple of more sentences. That’ll really show how upset I am and how unfair life is. Booooooo

The linked generator is for rc models that run on gas-- it’s just a way to get some electricity out of the fuel. trying it on a already electric vehicle is… well, let’s call it special.