Post #9456

When you initially connect an inverter to a battery system, or you connect a battery to an inverter system, you need to pre-charge the capacitors in the inverters. I recommend using a 50ohm 10w resistor on a 48v system. Install alligator clamps on the resistor with a short length of wire. In my system I always have a 125amp breaker on my batteries. What I do is turn off all breakers on my batteries. I then jump around one breaker with a resistor and watch for the inverter to light up. Might take 10-30 seconds. Once you see signs of life in the inverter, you can turn on the battery circuit breaker and then all the other battery circuit breakers as well. If you don't do this you will most certainly damage your breakers or even the BMS. I can tell you that trying to cold start a victron inverter by simply turning on the battery breaker will cause so much inrush current that the BMS will shut down with a "short circuit protection" error. "Precharge resistor"