30second 120kW battery pack
 

I am designing my EV battery pack to A8 project and target is to make 120 kW for max about 30 seconds acceleration (standing mile).

I havent yet decided about the motors but I could still need some help on the EV design specs. So battery should have minimum weight I have made some calculations:

Voltage 350-370V
P=120000W
I= 342A with that 350V

30s-->0,0083hours

C=342Ax0,0083=2,84Ah

With 20% margin that would need 3,5 Ah pack.

What would you recommend using?.

I would like to use something like these:
GTL Rechargeable 3.7V "5800mAh" 26650 Lithium Battery w/ Protection Circuit Module - Brown (2 PCS) - Free Shipping - DealExtreme

Tesla is still using 18650 type batteries?

Hi Vekke, that sounds very similar to a drag racing pack, but those cells you identified are low amperage devices. Here's one reviewer's quote.
"Delivers current up to 8-9 A without problems, then turns off the PCB."
You're only asking for 342 A, which seems small, but you'd still need to parallel almost 50 of these cells for that kind of current. Competitive EV drag racers aren't hitting the track with less than 2000 amps on tap these days.
Check out the National Electric Drag Racing Association forums. Most of those guys are either going LiPo or some proprietary cells by Derek Barger at
Battery Packs
Here's aother racing battery supplier, John Metric. He also races the standing mile.
ampahaulic.com

So limiting factor is max A batteries can push out.

Battery test-review 18650 summary

If I have batteries that can push lets say 30A. I would need:

11 pcs in paraller to get 340
+ 100pcs of those pack in series to get 370V
Total of 1100 batteries?

Is the math correct?

Actually a chevy volt pack can do 380-400v & I've been to 600 amps on mine for 30 secs on monster hill. Not bad for $2500. You are going to be in a different neighborhood however.

For something short burst of only 30sec look into Ultracapacitors such as the New Maxwell 3400F 2.85V Boostcaps. These are light weight and extremely powerful. Batteries will not give you the power that these can provide!

GH :thumbup: