Originally Posted by mcf12
Wire the charger directly to the battery, not through the contactor. It's actually better if the charger isn't connected to the controller when charging. If you want an extra safety let the BMS cut off power to the charger with a relay on the AC input.
I used one of these solid state relays on the charger port to let the BMS shutoff charge current. The charger sees the current drop to zero and shuts down.