I have a FD max power battery that has stopped charging it will not let the charger charge the battery it’s still 50% full and not that old .I have tested it against a new battery the same and it appears to be missing a earth from the Center pin having a 4pin connector .charger has been checked and works fine what would cause a loss of earth?BCM? Is it possible to reset or maybe discharge battery fully to see if it still will not charge?or maybe replace the BCm anyone know what type is used and are they available to buy ?thanks in advance .
The BMS is for charge only and may be doing its job rather than being faulty.
The reason for disconnecting the ground could be a group of cells is below the low voltage cut off limit, above the voltage limit, or too hot. Most likely is a group too low in voltage.
Previous FD batteries used a Daly BMS.
I would open up and check each individual cell group voltages. However I would be reluctant to reuse the battery as they are potted and the nose cone design doesn’t seem to be too reliable as a single method of water protection.