ChargeMaster 12/25-3 battery charger/converter

The ChargeMaster 12/25-3 by Mastervolt, part number 44010250, is a fully automatic battery charger designed for marine applications and recreational vehicles. This model provides fast and complete battery charging regardless of the available AC power source, thanks to its automatic input voltage detection (90–265 V AC, 50/60 Hz). Weighing 1.8 kg and with compact dimensions (234 x 132 x 60 mm), it is easy to install in various environments. It is certified CE, ABYC A-31, SAE J1171/ISO 8846 (ignition protected), RRR, and RMRS, ensuring compliance with international standards.

Advanced 3-stage+ charging technology

The ChargeMaster 12/25-3 features Mastervolt’s 3-stage+ charging technology, optimizing battery life and performance. This process includes BULK (fast charge from 0 to 80% at maximum current), ABSORPTION (charge at maximum voltage to 100% with decreasing current over 4 hours at 14.25 V), and FLOAT (maintenance charge at 13.25 V for wet batteries or 13.8 V for Gel/AGM batteries). It is compatible with a wide range of battery types, including flooded lead-acid, AGM, Gel, Spiral, and Lithium Ion (MLi) batteries. Automatic voltage and temperature compensation (sensor included) adjusts charging parameters to prevent overcharging and gassing, extending battery life. The integrated memory function prevents overcharging in case of unstable AC power.

Versatility and charging capacity

With a nominal output voltage of 12 V and a total charging current of 25 A at 13.25 V, this charger can handle battery banks with a recommended capacity of 50 to 250 Ah and can charge banks up to 1000 Ah. The ChargeMaster 12/25-3 stands out with its three equal battery outputs, each capable of delivering 25 A. Unlike some larger models in the ChargeMaster range that may have a main output and two 10 A outputs for starting batteries, this model provides balanced current distribution across all outputs. It can also operate in constant DC power mode without connected batteries, ideal for powering lighting or a refrigerator. Galvanic isolation ensures enhanced installation safety.

Integration and monitoring

The ChargeMaster 12/25-3 is fully compatible with the MasterBus network, Mastervolt’s decentralized communication system. This compatibility enables centralized or remote monitoring and control of the charger and other system devices (inverters, generators, batteries). A bright LED display on the front panel provides essential information such as charging current and voltage, charging stage, and battery level. Three adjacent buttons allow system control. While most ChargeMaster models are MasterBus-compatible, the 12/10, 12/15-2, and 24/6 models in the same range do not offer this connectivity via a single cable. The device offers comprehensive protection against overheating, overcharging, short circuits, and high/low battery voltages, ensuring safe and reliable operation in ambient temperatures from -25°C to 60°C.