larsb
1 MW
Opened the damaged battery pack. It is made of 20s5p Samsung 25R with four years of nearly daily use.
All spot welds are still ok and all battery groups but one are at 4.08V, group 8 is at 3.63V, that must be the explanation to the rapid decline of the pack in the last weeks.
Could be that batteries just got too much out of balance to be corrected by the bms or that the bms is faulty, doesn't really matter as it's worn to the bone with constant charges to 4.2V, discharges down to 3.3V and a lot of current requested
All spot welds are still ok and all battery groups but one are at 4.08V, group 8 is at 3.63V, that must be the explanation to the rapid decline of the pack in the last weeks.
Could be that batteries just got too much out of balance to be corrected by the bms or that the bms is faulty, doesn't really matter as it's worn to the bone with constant charges to 4.2V, discharges down to 3.3V and a lot of current requested