# Coupling Solar Panel to LiFePO4 batteries



## sailfish11 (Sep 15, 2007)

bobgratonii, welcome to the forum!

If you haven't already, look at the alternator and perpetual motion sticky. It should answer your questions.


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## bobgratonii (Jan 10, 2009)

Thanks for the welcome,

but it is not for perpetual moving, i think about a regen while braking mode. But thanks for the link it contains helpfull informations.


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## reddwarf2956 (Dec 1, 2008)

bobgratonii said:


> This first thread is about a question i have looking for and didn't find any answer.  ''*The*'' Question if after the description of my project.
> 
> For now, my plans and shema i hope to sucess doing a
> 2003 Mazda protege 5 EV consisting of :
> ...


The ideas for the car sounds great. As for the alternator and solar ideas, realize that the switch from small voltage to high voltage means high amps will go to low amps. This in turn will mean the time needed to recharge will go longer. We are talking weeks to charge the pack with solar, or single digit regen on a DC motor car which means more weight added.

I like the idea of using the solar charger to power a small fan during the summer to cool the car when it is in the (where I'm at, Texas) summer sun. I doubt 20 W heater will work in Canada.

Don't get me wrong, they both can be done. But, is the benifit worth it?

JN


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## slurryguy (Dec 16, 2008)

I have no experience with alternator for regen brakes, and I have my doubts about whether the added complexity and weight will pay for themselves with increased range from battery recharging. 

However... the idea you propose has been very recently attempted and partially documented on YouTube in a Chevy S10 Pickup Truck EV Conversion. 

http://www.youtube.com/watch?v=zhGEiusexJ4

http://www.youtube.com/watch?v=pZ77La0MS4g

http://www.youtube.com/watch?v=IWCO5P24zHE


The builder also describes his efforts in more detail on his website:
http://www.northrim.net/wyanders/ev/

Scroll down his index on the left side. Page 20 describes his Regenerative braking system.


I'm not endorsing his technique as practical. In fact, I have my doubts about where it is worth the expense and effort. I'm also not willing to dismiss it out of hand completely either. I'm willing to be open minded and see what his results are.

The point of my post is that the idea has been attempted, and I would certainly be interested in seeing objective data about what this system does for this builder's range.

It would also be great to see what his range would be if his truck were lighter by removing the entire alternator regen system and compare his range with the lighter vehicle vs the range he got with the heavier regen equiped truck. (I suspect he's unwilling to remove all of his work just for my personal entertainment and education, though.)

I have no idea if this information will be helpful to you, but there it is.


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## bobgratonii (Jan 10, 2009)

Considering the fact of the weight i have to assume that it seams discutable. Maybe, with the time i will have, i could do a ''ready to take out'' system. If i can do that, i will and put the numbers. In fact i would love an AC system for regen, but for the price and complexity i doubt to make it throught. In fact i haven't seen a good AC motor for this purpose and no controler at all.


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