Mastervolt Battery Chargers

Sizing a Mastervolt battery charger correctly

A multi-stage charger works through bulk, absorption and float stages automatically, tapering current as the battery approaches full charge rather than holding a fixed voltage that can overcharge a bank left on charge for days. The output current needs to suit the battery bank it is charging: too small a charger takes unnecessarily long to reach absorption, while an oversized charger relies entirely on the battery's own acceptance rate and the charger's stage logic to avoid overcharging, so it is worth checking the recommended output-to-capacity ratio rather than simply buying the largest model available.

Chargers with multiple independent outputs can charge separate battery banks, such as house and engine start, at different rates without one bank's state affecting the other, useful where the two banks use different battery chemistries. Confirm the charge profile suits your battery type, since a profile tuned for flooded lead acid is not appropriate for a lithium bank without adjustment, and check the unit's AC input range if it will run from a generator as well as shore power.