Mastervolt ChargeMaster 25A 12V Output 120/230V Input is a compact, high-performance battery charger designed to keep your batteries powered anywhere in the world. Featuring 3-step+ charging, memory protection, and seamless MasterBus compatibility, it delivers fast, complete charging for multiple battery banks with reliability you can trust.

Key features

• Three equal charge outputs to support multiple battery banks with a total charging current of up to 25 A.
• Auto-ranging worldwide operation—handles mains from 90 to 265 V, 50/60 Hz without manual settings.
• 3-step+ charging with IUoUo profile for fast, safe charging across gel, AGM, wet and Lithium Ion batteries.
• Cos phi 1 regulation optimizes charging efficiency when power is limited by generators or imperfect mains.
• Memory function protects against overcharging during unstable power supply.
• MasterBus ready—connect to other Mastervolt devices with a single cable for centralized monitoring and control (networking available on ChargeMaster 12/25-3).
• Robust build with metal-on-metal fittings to ensure secure connections and resist corrosion/overheating.
• Compact, global-ready design with built-in cooling (vario fan) and IP23 protection for versatile use on boats, caravans, or off-grid setups.

Technical specifications

• Total charge current: 25 A
• Number of battery outlets: 3
• Nominal output voltage: 12 V
• Battery capacity range: 50–250 Ah
• Nominal input voltage: 120/230 V (90–265 V), 50/60 Hz AC
• AC connection: 2 m AC cable
• Charge characteristic: IUoUo, automatic 3-step+ for gel/ AGM/ wet/ Lithium Ion
• Charge voltages: Bulk 14.4 V; Absorption 14.25 V; Float 13.25 V (wet); 13.8 V (gel/ AGM)
• Absorption time: ~4 hours
• Power consumption (DC side): < 2 mA
• Full load power (AC): 450 W
• Temperature range: -25°C to 60°C (derating >40°C: -13°F to 140°F)
• Protection: IP23
• MasterBus: Yes
• Dimensions (L x W x H): 9.2 x 5.2 x 2.4 inches

What's in the box

• ChargeMaster 12/25-3
• DC wiring: 2 positive (red) and 1 neutral/negative