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
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Three equal charge outputs to support multiple battery banks with a total charging current of up to 25 A.
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Auto-ranging worldwide operation—handles mains from 90 to 265 V, 50/60 Hz without manual settings.
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3-step+ charging with IUoUo profile for fast, safe charging across gel, AGM, wet and Lithium Ion batteries.
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Cos phi 1 regulation optimizes charging efficiency when power is limited by generators or imperfect mains.
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Memory function protects against overcharging during unstable power supply.
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MasterBus ready—connect to other Mastervolt devices with a single cable for centralized monitoring and control (networking available on ChargeMaster 12/25-3).
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Robust build with metal-on-metal fittings to ensure secure connections and resist corrosion/overheating.
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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
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Total charge current: 25 A
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Number of battery outlets: 3
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Nominal output voltage: 12 V
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Battery capacity range: 50–250 Ah
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Nominal input voltage: 120/230 V (90–265 V), 50/60 Hz AC
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AC connection: 2 m AC cable
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Charge characteristic: IUoUo, automatic 3-step+ for gel/ AGM/ wet/ Lithium Ion
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Charge voltages: Bulk 14.4 V; Absorption 14.25 V; Float 13.25 V (wet); 13.8 V (gel/ AGM)
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Absorption time: ~4 hours
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Power consumption (DC side): < 2 mA
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Full load power (AC): 450 W
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Temperature range: -25°C to 60°C (derating >40°C: -13°F to 140°F)
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Protection: IP23
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MasterBus: Yes
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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
| General Specifications |
| Total charge current |
25A |
| Number of battery outlets |
3 |
| Nominal output voltage |
12V |
| Charge current second output |
25A |
| Charge current third output |
25A |
| Battery capacity range |
50-250ah |
| Nominal input voltage |
120/230 V (90-265 V), 50/60 Hz |
| AC connection |
2 mtr AC cable |
| Power supply mode |
yes |
| Display/read-out |
LED display |
| Technical specifications |
| Charge characteristic |
IUoUo, automatic 3-step+ for gel/AGM/wet/Lithium Ion |
| Charge voltage Bulk |
14.4V |
| Charge voltage Absorption |
14.25V |
| Absorption time |
4 hours |
| Charge voltage Float (wet batteries) |
13.25V |
| Charge voltage Float (gel/AGM batteries) |
13.8V |
| Voltage compensation |
Automatic |
| Power consumption (DC side) |
< 2 mA |
| Full load consumption (230 V AC) |
450 W |
| Current Control function |
no |
| Temperature range (ambient temp.) |
-25 °C to 60 °C, derating > 40 °C
-13 °F to 140 °F |
| Protection degree |
IP23 |
| Cooling |
vario fan |
| MasterBus compatible |
Yes |
| Dimensions |
9.2 x 5.2 x 2.4 inch |
