The battery maintainer is a charging device that enables an extra battery bank to be kept ‘topped up’ from the main battery bank which has the charging device(s) connected to it (e.g. alternator, battery charger, solar cell / wind turbine etc). The unit transfers approximately 3A(12V) and requires the charging devices to be turned on to work. It is best suited at keeping a starter battery topped up and maintained by the charge that your house bank receives.

How does it work? The unit is activated when the main battery has reached around 13.3V (26.6V at 24V) and allows excess power to be transferred from the primary charging system to charge / maintain an auxiliary battery bank. The transfer current is 3Aat 12V.



  • Ideal for use on Boats, Camper vans and with Solar / Wind top up.
  • IP65 Waterproof (rated to)
  • Ignition protected and reverse polarity protected.
  • Power Saving. The battery maintainer uses FETs instead of relays and as such uses very little power itself (less than 1mA). This allows your solar harvest to be more efficiently distributed rather than lost across inefficient relays. 
  • It is simple to install and is a low cost product. Saving time on installation and money on repeatedly replacing destroyed flat batteries.
Weight 250 g

Sterling Power

Manufacturer Part Number


Output (V) DC


Current (A)



L140 X W45 x D40mm

Weight (kg)



2 Years


There are no reviews yet.

Be the first to review “Sterling Power Battery Maintainer 24/12V 1A – BM24121”

Your email address will not be published.

You may also like…