Higher resistance is usually caused by capacity fade. I know of no way to reduce it you just have to replace the cells. You could take them out and cycle them four or five times. I did this with some cells that had been sitting on a shelf for years and I got 100% of the capacity back. This may not work for cells that were regularly cycled in a vehicle.Bought CALB ca's about 5 yrs ago and had some 4 out of 45 cells come up with high resistance out of spec and replaced by CALB on warranty. I have now 4 more with resistance higher than 1.2 milliohms (spec is .7 or lower) with one of those 4 at 2.2 milliohms. These are all figures reported by Orion BMS.
Anybody have any insight into why this happens and what a recommended course of action to take? buy 4 new cells? look for used cells? It seems that especially the highest resistance cell is cutting into usable range. I still have resting charge of above 3.2 on my best cell when BMS is cutting back 1238 controller output.
I guess this is a good question because I think I have asked it 3 times with very little response.
Thanks in advance