Victron Battery Balancer (Battery Balancer) - BBA000100100100

Victron Battery Balancer (Battery Balancer)

The problem: the lifetime of a battery bank can be considerably shortened due to unbalanced state of charge.

A slightly higher internal leakage current in one of the batteries in a bank of several 24 or 48V batteries connected in series/parallel would result in a lack of charge of that battery and the batteries connected in parallel, and overcharging of the batteries connected in series. In addition, when new cells or batteries are connected in series, they must all have the same initial state of charge.
Small differences will be neutralised during absorption or equalisation charging, but larger differences will result in damage due to excessive gassing (overcharging) of batteries with a higher initial charge, and sulphation (undercharging) of batteries with a lower initial charge.

The solution: battery balancing

The Victron Battery Balancer (Battery Balancer) balances the state-of-charge of two 12V batteries connected in seriesor several parallel strings of batteries connected in series.
In the event that the charging voltage of a 24V battery system rises above 27.3V, the Battery Balancer will activate and compare the voltage reaching the two batteries connected in series. The Battery Balancer will draw a current of up to 0.7A from the battery (or batteries connected in parallel) with the higher voltage. The resulting charge current differential will ensure that all batteries converge to the same state of charge.
If necessary, several balancers can be placed in parallel.
A 48 V battery bank can be balanced with three 48 V Battery Balancers from Victron.

Victron Battery Balancer LED Indicators

Green: active (battery voltage > 27.3V)
Orange: lowest active battery circuit (deviation > 0,1V)
Orange: Highest active battery circuit (deviation > 0.1V)
Red: alarm (deviation > 0.2V). Remains active until the deviation has been reduced to less than 0.14V, or until the system voltage drops below 26.6V.

Alarm relay

Normally open. It closes when the red LED lights up and opens when the red LED goes out.

Resetting the alarm

Two terminals are available for connecting a push button. Interconnecting the two terminals resets the relay.
This reset condition remains active until the alarm ends. The relay will then close again when a new alarm occurs.

More insider information and control with the midpoint monitoring function of the battery monitor BMV-702.

The BMV-702 measures the midpoint of a string of cells or batteries. It displays the deviation from the ideal midpoint in volts or percentage. Separate percentage deviations can be set to trigger a visual/audible alarm and to close a de-energised relay contact to set a remote alarm.

In the event that the charging voltage of a 24V battery system rises above 27V, the Victron Battery Balancer will activate and compare the voltage reaching the two batteries connected in series. The Battery Balancer will draw a current of up to 1A from the battery (or batteries connected in parallel) with the higher voltage. The resulting charge current differential will ensure that all batteries converge to the same state of charge.