Quote:
Originally Posted by MarkM66
Cool project.
Maybe you already stated this, but what kind of batteries are you going to use? How many or what size will they be?
Any idea on milage range between charges?
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Thanks Mark.
Since I am so freakin longwinded
, I
underlined the answers to your questions, so you can skim through if you don't feel like reading yet another one of my novels.
Actually I didn't mention that - I meant to but forgot. I plan to use
A123 (26650) cells. They're
lithium-based, but I can't remember the exact compositition right now. They're the highest energy density of any currently available battery. They are what come in the larger DeWalt cordless tool battery packs. The downside is they're not commerically available. The company won't sell them to the general public. I have three options: Get an inside connection, get sponsorship, or buy 225 new DeWalt packs from a distributor and start dissecting (and recycling a lot of plastic).
They're little
round cylindrical cells, about 1" diameter, and a tad over 2.5" long. I need
1800 of them!
18 strings of 100 series-wired cells, then paralleled. They're 3.3 volts each, so the 100 cells in series gives 330 volts for each string; then wiring those strings in parallel gives the 2070 amps. The other thing about these cells is they're the only ones that can be pushed as hard as they can, to deliver 2000 amps from such a small pack. I've done the math on all the others, and nothing comes close.
To hold them all together, I will be doing CAD/CNC cases that the cells drop into. The cases will fit under the seats, between the floor and belly pan, and between the frame rails and driveshaft tunnel, and kind of roll up behind the seats a little. I think it's going to work out to
three cases on each side. That would make
each case about 50-60lbs - easy to handle. The
whole pack will weigh
no more than 400lbs with cases, battery management system, etc. That's the key to the 1200lb final weight goal.
I should get
50-60 miles off a charge, driving conservatively, and maybe
half that pushing hard. The funny thing is I would have been happy with ten, because I just wanted to be able to race. The additional range comes from A123 cells being so incredible. I think I'll have enough to do some short road courses. I'm seriously considering a little generator trailer (with a matching T bed) that would give me pretty much unlimited range. It would also be nice for recharging at the track.