NiMH 'Hybrid' batteries (Eneloop, etc)
Okay, so I've been recently re-acquainted with NiMH AA batteries, after pretty much giving up on them a while ago. This new breed of NiMH 'hybrid' or 'low discharge' batteries from Sanyo (marketed as Eneloop), Rayovac, and others have a quality that previous NiMH batteries did not; they hold a charge! I think the literature says the will hold like 85% of their charge after 1 year.
So, my next question is whetheror not these could be a viable EV battery.
1.2V per cell, 2000mAH, discharge rate up to 4000mA, weighs 27g.
40 cells => 48V, 2AH, weight of 1080g (x10=20AH, 21600g or 47.62lbs)
Does this add up correctly? While this is like SLA, maybe there are version that are lighter?
http://www.eneloop.info/uploads/media/Datasheet_-_HR-3UTG_01.pdf (huh, called 'Twicell' on the spec sheet)
I think it should be 10*1080=10800g =10.8kg =23.76Lbs Sounds a bit better! :)
Doh! Thanks for checking my arithmetic!
Unless you want an EV to leave it parked the standard NiMH are much better due to higher energy density.
You get 2800mAh for about the same weight and size.
Ok... so how would one go about charging such a system? I certainly hope you would not have to unload all those AA batteries and stick them into 4 battery chargers :) ... Seriously - would one just treat the whole mess as a single 48v 20ah battery and buy a charger for that?