Does it work with the SmartBMS?

Yes, the 123\PowerSwitch is a perfect companion and it will be functional in no time.

There are multiple configurations possible:

Use one 123\PowerSwitch for the whole installation

In this configuration, the 123\PowerSwitch will be used as “last line of defense”. When a cell has an error, for example when a cell voltage is too high or too low, the PowerSwitch will be turned off and thus all connected chargers and loads will be disconnected from the battery. When the error is gone, the PowerSwitch turns on again.

This configuration is mostly used with combined chargers/inverters which is a setup where the charger and inverter are in the same device like the Victron Quattro/Multiplus.

Connect the 123\PowerSwitch black control wire (negative) to the battery pack negative.

Connect the 123\PowerSwitch red control wire to the “common contact” of the End Board Charge signal relay potential free contacts.

Connect the End Board Charge signal relay “allowed to charge” to the Load signal relay “allowed to discharge”.

Connect the End Board Load signal relay “common contact” to the battery pack +.

Use two 123\PowerSwitches: one for all chargers and one for all loads/inverters

The benefit of this configuration is that when one PowerSwitch is off, for example the “allowed to discharge”, the other PowerSwitch (“allowed to charge”) stays on. Thus if a battery cell is empty, the charger will stay connected to charge the pack.

Connect a wire from the battery pack + to the “common contact” (middle hole) of the Load signal relay and to the Charge signal relay.

Connect the 123\PowerSwitch black control wire (negative) of both PowerSwitches to the battery pack negative.

Connect the End Board Charge signal relay “allowed to charge” pin to the charge 123\PowerSwitch red control wire.

Connect the End Board Load signal relay “allowed to discharge” pin to the discharge 123\PowerSwitch red control wire.