Hi there. Thanks for reading. I have a system configured with 3 x Pylontech US5000 units supporting 3 x Victron Quattro 8000 inverter/chargers. We are seeing a drop from charge current 80A per module to 20A completely randomly. This happens during bulk charge (around 30-60% SOC) so I don’t believe it is cell balancing. The temperature of the cells is well within range, and we don’t get any error messages from the BMS for overvoltage or similar. Has anyone experienced this before or could shed some light on the issue? I’ve attached a trace showing this drop and the voltage of the modules. Thanks in advance!
Also just to add that after this happens, there is no way to recover the 80A charge limit other than fully cycling the system by turning them off and on again.
Have you checked the min/max cell voltages?
51.5V means an average cell voltage of 3.43V (Pylontechs are 15s) and if im not mistaken they do start to balance above 3.45V, so it could very well be a cell shooting off with its voltage