It is recommended from time to time to recheck all the cells, for example, if you notice that your voltage drops unusually low much sooner than before.
Charging the battery to 100% and then discharging it fully you will see which cells have the lowest voltage.
The best for testing cell health is to run the battery pack under load and then on the BMS checking how each cell behaves, if some cells have much lower voltage than others then that could be an indication about the cells in a worse condition.
Be sure always to check the battery serial connection like busbars and screws.
Battery Voltage Test: Use a multimeter to measure the voltage of each battery cell individually. A healthy cell should have a similar voltage reading to the other cells in the battery bank. If you find a cell with a significantly lower voltage reading, it may indicate a bad cell.
Cell Temperature Check: Check the temperature of each battery cell. A cell that is noticeably warmer than the others, especially during charging or discharging, could indicate a problem.
- Battery Load Test: Perform a load test on the battery bank. This test evaluates the capacity of each cell to deliver power under a load. If one cell consistently performs poorly compared to the others, it may be a sign of a bad cell.