Regen: Why is it not possible to generate electricity when the EV is in motion?

hemj · 20th September 2022, 12:34

I'm not sure if anyone has already said this as directly as I'm saying it. The extra energy required to overcome the resistance created by the regen will be more than the energy generated by the regen.

It's like giving someone 5 chocolates for getting 4 chocolates back of the same brand. Net loss always. Unless some great innovations happen and you get back 5 chocolates. But then you will be adding extra weight and complexity for getting the same amount back, which makes no sense.

And there is never a situation where you are going to get more than you put in, the laws of thermodynamics don't allow it.

fordday · 20th September 2022, 13:21

Quote:

Originally Posted by T-Bone

let's take a 20kwh battery pack and just divide it into two (split) 10kw + 10kw. So use one 10kw pack while the other charges and switch the pack as needed. FYI, I have seen low rmp high voltage/current generators. Fix one (just an alternator) and use it to charge the battery pack. I'm sure we can achieve that with advancement in tech.

Not possible ever.

Lets say in your experiment, the two batteries are B1 and B2.
If B1 is driving the car and the B2 is getting charged, where will the power come from? It will come from B1 only, which drives the wheels, which in turn will drive the alternator.

At the end of the day B1 charges B2.

R_throttle · 29th September 2022, 11:46

Moral of the story, regen braking already does what you asked for, but then it slows down the vehicle. With dynamos on cycles, there was an engine (human) continuously pedalling.

Similarly can't we actually use a gearing mechanism or a linkage between the solid axle and a gear attached to the other end to run a dynamo? I also appreciate the one who created the thread as this was one of my major doubts for the past couple of years.

Since the rear wheels of a FWD car is moving freely,ie, with no extra force acting on it, can we convert the rotary motion of those rear wheels (provided they are connected via a solid axle) to electrical energy? I know I am under educated when it comes to electricity & electrical systems but even though these kind of thoughts has been revolving around my head. Sorry if this was a noob thinking.

20th September 2022, 12:34	#46
hemj Newbie Join Date: Oct 2021 Location: New Delhi Posts: 18 Thanked: 35 Times	Re: Regen: Why is it not possible to generate electricity when the EV is in motion? I'm not sure if anyone has already said this as directly as I'm saying it. The extra energy required to overcome the resistance created by the regen will be more than the energy generated by the regen. It's like giving someone 5 chocolates for getting 4 chocolates back of the same brand. Net loss always. Unless some great innovations happen and you get back 5 chocolates. But then you will be adding extra weight and complexity for getting the same amount back, which makes no sense. And there is never a situation where you are going to get more than you put in, the laws of thermodynamics don't allow it.
	() Thanks

29th September 2022, 11:46	#48
R_throttle Newbie Join Date: Jun 2021 Location: Pathanamthita Posts: 16 Thanked: 20 Times	Re: Regen: Why is it not possible to generate electricity when the EV is in motion? Moral of the story, regen braking already does what you asked for, but then it slows down the vehicle. With dynamos on cycles, there was an engine (human) continuously pedalling. Similarly can't we actually use a gearing mechanism or a linkage between the solid axle and a gear attached to the other end to run a dynamo? I also appreciate the one who created the thread as this was one of my major doubts for the past couple of years. Since the rear wheels of a FWD car is moving freely,ie, with no extra force acting on it, can we convert the rotary motion of those rear wheels (provided they are connected via a solid axle) to electrical energy? I know I am under educated when it comes to electricity & electrical systems but even though these kind of thoughts has been revolving around my head. Sorry if this was a noob thinking.
	() Thanks