I bought six working packs from alarmhookup. I wish they were still available. I found them dependable. THey're stored in an old grill outside for the summer.robocam wrote: ↑Jul 11, 2018 4:23 pmWhen I measure the voltage at the XT-60 connector, it reads zero volts but when I measure on the circuit board, it reads 34.9V. Does this mean that the BMS has cut off the power? I'm going to try charging one of them with my ebike 36V charger to see what happens.
But to your problem, the BMS is powered off one or more cell groups and has likely run then down below the 2.5V cutoff. Unplug the white connector with the 10 balance wires and carefully measure the cell groups. If you see one or two under 2.5V, that's why the battery is shut off. They shouldn't charge if this is true.
Can they be recovered? It will depend on how low they went and your appetite for risk, Read up on what happens when you run lithium too low, Scary stuff. If they are not too low, and you want to recover them, you would have to charge the low groups separately and you have to bring them to the same level as the others. These boards have no balance circuits so this is the only time you can get them equal. You must monitor the voltage for bakance. Another option, if the cells were deemed unsafe, is to break up a battery and replace the dead cells with charged ones. Either way, be safe.