Battery Balancer for 12V to 24V/48V Banks | Victron BBA000100100

The Victron Battery Balancer equalises the charge across two 12V batteries wired in series to form a 24V bank. It suits installers building 24V systems from 12V batteries, where small differences in condition or charge acceptance cause drift over time. Left alone, this drift shortens battery life and cuts usable capacity. The balancer corrects it automatically, with no programming or user adjustment needed.

Victron battery balancer key features

• Balances two 12V batteries wired in series within a 24V bank, correcting voltage differences between them.
• Activates once the difference between the two batteries exceeds 0.1V, drawing up to 0.7A from the higher battery.
• No configuration, software or user intervention needed once wired in.
• LED indicator shows balancing activity, useful for confirming correct operation during checks.
• Multiple units can be connected in series for 48V systems built from 12V batteries.
• Sealed enclosure suited to battery boxes, plant rooms and marine or vehicle compartments.

How it works

In a 24V bank made from two series-connected 12V batteries, one battery often charges or discharges slightly faster than the other, due to manufacturing tolerance, age or temperature. Over repeated cycles this gap widens, leaving one battery overcharged while the other stays undercharged. The balancer monitors the midpoint voltage and draws current from the higher battery whenever the imbalance passes 0.1V, bringing both back into line.

It works passively and continuously, with no connection to the charge controller, inverter or battery monitor needed. It sits alongside the bank and does its job independently, which makes it simple to retrofit into an existing 24V system or specify for a new one. For a 48V bank built from four 12V batteries, two Battery Balancers are wired in series to cover both halves.

Applications

• 24V battery banks assembled from two 12V lead-acid, gel or AGM batteries in series.
• 48V battery banks assembled from four 12V batteries, using two Battery Balancers.
• Off-grid solar installations where consistent charge balance extends battery service life.
• Marine and vehicle 24V systems where space for balancing equipment is limited.

Installation notes

Fit the balancer across the midpoint of the 24V bank, connecting to the positive and negative terminals of each battery in the pair. Confirm battery chemistry and wiring configuration before installation. For 48V banks, install two units in series and check polarity carefully. As with any DC battery wiring, use a qualified installer where the unit forms part of a wider solar PV, inverter or off-grid system.

What's in the box

• 1 x Victron Battery Balancer
• Connection cables for wiring across the battery pair