[LithiumaniacsEVRacing]

I have tested my Haiyin 400amp cells only to 100amps with my equipment, the factory claims they tested 400+amps per cell.

I have bought a basic automotive load tester (design for 12v batteries) that will pull 300amps, so I built a 1P 3S pack for testing. Will this work?

[LithiumaniacsEVRacing]

If it works I will video tape the draw and the voltage drop, should be interesting?

i know last year I started one of my diesel truck with a Turnigy nano tech pack, spun like hell!

[Ziggythewiz]

What voltage are your cells? Usually a 12V battery would be replaced by 4 lithiums (at least of the LiFeP04 variety).

[dougingraham]

3*3.7 (nominal voltage of those cells) = 11.1V Fully charged point would be 12.6V.

Seems like it should work. Will give you an idea of the sag at 300A anyway.

They should sag significantly less than a car battery. I will be interested to see what happens.

[Tesseract]

Originally Posted by LithiumaniacsEVRacing

I have tested my Haiyin 400amp cells only to 100amps with my equipment, the factory claims they tested 400+amps per cell.

I have bought a basic automotive load tester (design for 12v batteries) that will pull 300amps, so I built a 1P 3S pack for testing. Will this work?

Probably. To measure the internal resistance of the cells - which is what you really want to know - you need to compare the voltage at two different currents, not at 0A and, say, 100A. This is so you don't get an inflated resistance figure from the surface charge.

So, try measuring the voltage at, say, 100A then again at 200A. The difference in voltage divided by the difference in current (100A in this example) will give you the total resistance of the pack.

You can go one step further and use a digital multimeter to read the voltage across each cell while testing at the two currents which will help you sort out any outliers - ie, those cells with much higher or lower resistance.

[LithiumaniacsEVRacing]

Originally Posted by Tesseract

Probably. To measure the internal resistance of the cells - which is what you really want to know - you need to compare the voltage at two different currents, not at 0A and, say, 100A. This is so you don't get an inflated resistance figure from the surface charge.

So, try measuring the voltage at, say, 100A then again at 200A. The difference in voltage divided by the difference in current (100A in this example) will give you the total resistance of the pack.

You can go one step further and use a digital multimeter to read the voltage across each cell while testing at the two currents which will help you sort out any outliers - ie, those cells with much higher or lower resistance.

This test is very late, my packs are built, but will give me a max draw point on these cells. Jeff, I will do what you recommended. I will complete tests at 100amps watch how long cells hold till lowest, then 200amps, then 400amps. The cells were tested in China up to 100C (they say) so 400amps should hold.
I will be very satisfied with 300 to 400amps per cell, will work for Shiva's at 10P. I will press the issue and test till they go BOOM! In an enclosed lexan box, just want to see the cells max point before the Lipo fireball!

[LithiumaniacsEVRacing]

My 12v 400amp MONSTER!


Video Soon!

[Ziggythewiz]

Oh good, that's the charger. I saw the leads and thought you were going to pull 400 Sam's Club amps.

[LithiumaniacsEVRacing]

Tested a 4S pack of my Haiyin cells at 300amps for 15 seconds.
Starting voltage 15.69v, after the 15 second 300amp draw final pack voltage 15.24. Seems like a 2.85% drop.

Update,the actual time was 17 seconds of amps draw, I used a timer while watching video.

http://youtu.be/AuzxsPP-j7E

[LithiumaniacsEVRacing]

Tested a 3S pack to record voltages.

http://youtu.be/Y9vPVLwB50U

Start 12.18V
200amps 9.91V
250amps 9.63V
300amps 9.42V

This test was timed on the video, the total time drawing amps was 1 minute 26 seconds.