18650 testing

[wannesd]

What do you guys use for testing 18650 batteries?

I received 140 batts, and tested them in my framebag, I have room for 60 more.
Final setup will be 20s10p.

I would like to test them all for internal resistance and capacity.

What do you recommend for doing this?

I found this charger which can test for capacity and IR, and hook up to a pc, but haven't seen any mention of it on ES yet.
http://www.skyrc.com/index.php?route=product/product&product_id=219

Any better solutions out there?

 

[amberwolf]

If you read around the other threads for this, youll see a number of options.

 

[redilast]

I've used hobby chargers for loads, and CBA III before. But I ended up going with an electronic load because its more accurate and flexible. My electronic load can do loads up to 30A/150W. The load connects to my computer via USB. Then I use an extech internal resistance meter to measure resistance at 1Khz AC. There are hobby chargers like you mentioned that do resistance testing, but it won't be very accurate. Do to a truly accurate resistance test you need 2 load wires and 2 sense wires connected to the battery. There are some cheapo like $30 meters on ebay I think that work okay, but I've never used one. I think dr bass has one, or used to have one anyways.

 

[flippy]

this works fine: http://www.ebay.com/itm/181743302391

also get the 4 wire battery holder with it and you are done. it can also do 2.6A discharge tests.

 

[Pajda]

If you are looking for cheap but sufficiently accurate tester you should look on ZKEtech product http://zketech.com/ (you can find them on ebay) Good starting point for 18650 cell size is their EBC-A05 and A-10 models. The A-10 model is more powerfull up to 10A discharge and 5A charge and also much quieter, but it has lower resolution for voltage and current than the A-05(but still it is very accurate - I checked both models with precise 6 1/2 multimeter and both they were very well calibrated directly from factory).

 

[DVDRW]

I have bunch of these.
They work just great. Max 15V and 3 Amps, settable cutoff voltage. If you want more amps just put them parallel or use separate same value load resistor and after add up.
Nissan Leaf cell testing:

 

[Punx0r]

The manufacturing consistency of any new 18650 cells that aren't junk is very high. So high there is no point attempting to test the cells - chances are they are more consistent than your measuring equipment. Individual discharging/charging will simply unbalance them.

It's a good idea to test the finished pack, but this is as much a test of the BMS and charger as the battery itself.

 

[wannesd]

The manufacturing consistency of any new 18650 cells that aren't junk is very high. So high there is no point attempting to test the cells - chances are they are more consistent than your measuring equipment. Individual discharging/charging will simply unbalance them.

It's a good idea to test the finished pack, but this is as much a test of the BMS and charger as the battery itself.

Still, allex had a couple of duds in his pack, if I remember correctly.

 

[flippy]

so did i. 2 out of 400 might not sound many but they can wreak havoc on your usuable capacity.