Victron Batterij Balancer

The Battery Balancer balances the charge status of two series-connected 12V batteries or multiple parallel strings with series-connected batteries. If the charge voltage of a 24 V battery system rises to more than 27 V, the Battery Balancer turns on and compares the voltage of the two series-connected batteries. The Battery Balancer consumes a current of up to 1 A from the battery (or parallel connected batteries) with the highest voltage. The resulting difference in charging current ensures that all batteries switch to the same charging state.
If necessary, multiple Battery Balancers can be connected in parallel. For example, a 48V battery bank can be balanced with three Battery Balancers.