Mastervolt ChargeMaster 25A is a compact, high-performance 12V battery charger designed for boats, caravans, and off-grid setups. Its three equal output channels and worldwide operation simplify charging for multiple battery banks with reliable performance.
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Three equal outputs: Charge three battery banks simultaneously with a total charging current of up to 25 A.
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Auto-ranging worldwide input: Accepts 90–265 V AC at 50/60 Hz with no manual settings.
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3-step+ IUoUo charging: Fast, safe charging for gel, AGM, wet, and Lithium Ion batteries with automatic top-up.
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Cos φ1 regulation: Optimizes charging efficiency when power is limited by generators or marginal mains.
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Memory function: Prevents overcharging during unstable or fluctuating power supply.
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MasterBus ready: Connects to other Mastervolt devices with a single cable for centralized monitoring and control.
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Robust build: Metal-on-metal fittings provide secure connections and resist corrosion and overheating.
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Compact, global-ready design: Built-in vario fan cooling and IP23 protection for versatile use on boats, caravans, or off-grid sites.
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Output and battery compatibility: 12 V nominal output; suitable for battery capacity ranges from 50–250 Ah.
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Charge voltages: Bulk 14.4 V; Absorption 14.25 V; Float 13.25 V (wet) or 13.8 V (gel/ AGM).
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Absorption time: Approximately 4 hours to reach full charge.
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Power and efficiency: DC-side power consumption < 2 mA; full-load AC consumption around 450 W.
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Protection and climate range: IP23 protection; operates from -25°C to 60°C with derating above 40°C.
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Cooling: Vario fan ensures effective cooling in demanding conditions.
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Dimensions: 9.2 x 5.2 x 2.4 inches.
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What's in the box: ChargeMaster 12/25-3 DC wiring included—2 positive red leads and 1 neutral/negative.
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Nominal input: 120/230 V (90-265 V), 50/60 Hz.
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AC connection: 2 mtr AC cable.
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Display/read-out: LED display.
The ChargeMaster 25A keeps critical batteries ready in marine, caravan, or off-grid environments. Its three-channel design and MasterBus compatibility provide flexible, scalable charging for multiple banks, while auto-ranging input and robust protection deliver reliable performance wherever you are.
| 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 |
