Batteries

I had purchased some older but NEW batteries to increase the size of my initial pack. I now have 60 cells to put into my pack for 192 volt nominal system. It had been stated that the new old stock of the CALB SE cells actually had a small degradation of capacity just by sitting on the shelf at half charge. Out of 33 cells I found one that was at 270mv and would be considered by any other type of battery totally DEAD. Well not so with the LiFePO4 cells. I decided to do a slow charge to bring it back up to a level I could charge it with my PowerLab 8 charger. I did at 25 amps up to 3.6 volts and using a cc/cv algorithm which is standard for LiFePO4 cells. I then set it up to my discharge station and discharged the cell at 90 amps until it reached 2.6 volts. At which point it provided me with a total of 107 amp hours out of the cell. That is actually consistent with NEW cells right from the factory. I will test a couple more that were sitting normally at about 1/2 full to see what they give and to see if that makes any difference.

Pete :)