The service life of an expensive battery bank can be substantially shortened due to state of charge unbalance. One battery with a slightly higher internal leakage current in a 24 V or 48 V bank of several series/parallel connected batteries will cause under-charge of that battery and parallel connected batteries, and over-charge of the series-connected batteries. Moreover, when new cells or batteries are connected in series, they should all have the same initial state of charge. Small differences will be ironed out during absorption or equalize charging, but large differences will result in damage due to excessive gassing (caused by overcharging) of the batteries with the higher initial state of charge and sulphating (caused by undercharging) of the batteries with the lower initial state of charge.

The Battery Balancer equalizes the state of charge of two series-connected 12 V batteries, or of several parallel strings of series-connected batteries. When the charge voltage of a 24 V battery system increases to more than 27 V, the Battery Balancer will turn on and compare the voltage over the two series-connected batteries. The Battery Balancer will draw a current of up to 1 A from the battery (or parallel connected batteries) with the highest voltage. The resulting charge current differential will ensure that all batteries will converge to the same state of charge. If needed, several balancers can be paralleled. A 48 V battery bank can be balanced with three Battery Balancers.