# Re: [EVDL] How crazy am I?

```Ben,
Are you putting the cells in series or in parallel?
45 cells in parallel will indeed allow you to draw 45 times as much
current - but at the same voltage as a single cell (3.2V) 3600A still
gives 11kW.```
```
If yo uare putting the cells in series, then each cell can only do as
much currrent as a single cell and since all cells are stacked, that
current runs through *all* the cells, so the same 80A through them all,
but at 45 times the voltage of a single cell, so the same 11kW.
It is real simple - each cell contributes a certain amount of power:
3.2V x 80A = 256W.
So, 45 cells can do 45 times as much power: 45 x 256W = 11.5kW
Depending how you wire those cells, they can increase the total voltage
by stacking cells in series, or they can increase the current by wiring
them in parallel, you can even create a mix of series/parallel, for
example
3 strings of 15 series cells for 15 times higher voltage (48V) and 3
times higher current by adding up the currents through the 3 parallel
strings for a total of 3x80A = 240A. 48V x 240A = 11.5kW because the
power can never
be more than the sum of what each cell can deliver...

Hope this clarifies,

Cor van de Water
Chief Scientist
Proxim Wireless Corporation http://www.proxim.com
Email: cwa...@proxim.com Private: http://www.cvandewater.info
Skype: cor_van_de_water Tel: +1 408 383 7626

-----Original Message-----
From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Ben Goren via
EV
Sent: Thursday, July 24, 2014 2:38 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] How crazy am I?

On Jul 22, 2014, at 8:21 AM, EVDL Administrator via EV
<ev@lists.evdl.org> wrote:

> For example, the CALB 40ah cells I mentioned are rated for a maximum
> discharge of 2C (80 amps).  At 144v, 80a is 11.5kW.  Allowing for
losses,

I think I may be a bit confused.

If a single 40 Ah cell can provide 80 A (for a little while), shouldn't
45 of those 40 Ah cells be able to provide 80 A * 45 = 3600 A? That 80 A
would be at 3.2 V for 256 W. All 45 cells would be at 144 V, for 518.4
kW or ~ 500 hp. That's three times the power of the 260 Windsor engine
in the car today, and substantially more than you're going to get in a
stock muscle car of any era -- and waaaaay more than even a pair of
AC-50s or WarP 9s is rated for.

So...does discharge scale with the number of batteries, or is it limited
by the discharge of a single cell? If the former, I should be more than
fine with a 45-cell pack of CALB 40 Ah batteries or equivalent. If the
latter...I'm likely screwed....

Thanks,

b&
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