R25 30Q VTC5A all from Nicon if a cell is dropping it’s storage charge quicker than others then as fare as I’m concerned there’s some internal issue I put it to one side and thay just sit there until thay go bad . Not worth saving a few £ and have it bring a group down or reduce the pack overall capacity/IR. cells are only as strong as there weakest link in a pack.
I got 6 R25 that are at 0.005V died in a box on my shelf all picked out when building packs. Use them to calibrate my welder every so often Mostly I fined when I buy cells thay are with in 0.03V of eatch other and just match them up in groups normally end up with them no more then 0.004V
As much as I’d like to test IR I just fined it’s widely different on each devise I tested it on and don’t trust them
If you go to cheap you get a supply with a lot of noise. Personally I’m going more and more with Meanwell HLG as chargeres as thay seem to consistently have better quality than most supposed quality charger manufactures do. Down side is thay don’t have a indicator led or relay to turn off when the charger has no power. Every charger I had never cut of the supply to the battery it just held it at the max voltage
The IR-testing feature in chargers is essentially useless…as you have experienced. I’ve been using two of the earlier version of the ESR Meter sold at ProgressiveRC for over ten years now. They’re accurate and consistent for measuring DC IR: LiPo ESR Meter Mark II - ProgressiveRC
For measuring AC IR you can’t beat the YR-1030 or YR-1035 available from AliExpress. They’re within 10% of the readings from my BK Precision BA6010 Battery Analyzer.
Does anyone have some P42A cells from batch 2J905 it 2JC25? I was going to make a 12s2p but @kook was questioning my Tetris game so now I’ve gotta make a 12s3p and I’m one cell short. I have 31 cells from the 905 and 4 cells C25 batch
12S LTT BMS is under the Unity, it’ll just barely fit but I’m like 95% sure this is possible
@longhairedboy@Skyart If I need to save every last milimeter of length on a battery should I do a folded pack or just a standard semi flex pack? It’s a 6 by 6 12s3p with cells running axially
if the board’s nose is north you can use folded nickel east to west but not north to south, you risk stressing the welds with flex. You could use copper braid if space consumed by series wiring is a concern.