DIY Electric Car Forums banner

1 - 1 of 1 Posts

70 Posts
Discussion Starter #1
Re: [EVDL] discharge testing, and TS cells


two steel coat hangers a bucket of water and a stop watch.
A pair of meters...

I am going to do a 3 c draw down of Thunder Sky 90s today or ..really soon.
I will use about $15K worth of power equipment.
Yea I just can't do it simpler....more toys more fun!

It's a water cooled twin 400 amp IGBT power stage...Yes Otmar... It could
be motor controller proto type...
but it's the power stage in my 75Kw monster charger.

Then we are going to get a Agilent DATA aqusition system to drive this
thing, wire it just like I do a Plug Prius.. But with 400 amp contactors..
times 5

And do Grid charges and then flip a switch a do controlled current limited
discharges. Rise Repeat about 1000 time per pack.
Wait about what 3 months??

Oh yea we hit 1000 Cycles on the Thunder Sky 40 amphour pack. Last cycle was
29.6 amp hours. With all the limits still in.
I am doind 10 cycles today with the limits set to the published numbers.
4.25 volts peak and 2.500 volts floor, and 1 amp taper limits.
This should yield %100 of what ever is left in the 4 cells. This is a
reality check of what's still available in the cell set. I set if off last
night , it's still dark here, and I can't sleep....

I wonder what I am getting???

Keep in mind I know the capactiy of each cell is NOT the same. They all
don't drop off at the same time, or charge off at the same instant. They
take about 90 seconds to equalize with a 2 amp Reg. so they are not really
out, just they are not perfect. With Regs you can't drain them perfectly,
but you can fill them perfectly.

I am looking forward to doing a 4 set of 90s. Some folks out there are
having problems getting these to make big amps.. I need to know why. The 90s
are about the smalles cell size that I would recomend for a Real street EV.
The smaller ones just don't like 100s of amps of abuse.

100s more E-mails.. Gotta go

Rich Rudman

For subscription options, see
1 - 1 of 1 Posts