The Mastervolt CombiMaster 12/3500 inverter/charger is a compact, marine-grade power solution designed to keep essential systems online with seamless auto-switching and intelligent charging. Built for boats and yachts where reliability matters, it delivers quiet, hum-free operation for heavy and sensitive loads, even in demanding locations.
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Inverter output: 120 V true sine-wave output with configurable 60/50 Hz; continuous 3500 W at 40 °C; peak 5250 W (30 s); surge 7000 W (5 s); max efficiency 96%.
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Nominal DC input: 12 V (10.2–16 V).
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Battery charger performance: Smart 3-step+ charging that adapts to different chemistries; input voltage range 90–140 V; max input current 25 A (adjustable); max charge current 200 A at 14.25 V (configurable); battery temperature sensor included; automatic voltage compensation.
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Transfer and mains synchronization: Automatic transfer with 10 ms transfer speed; AC input 50 A (switched); AC output 85 A; transfer voltage range 90–140 V; transfer frequency range 40–65 Hz; synchronizes with mains.
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Power Assist: Prevents tripping the mains fuse when connected to weak shore power or a small generator, delivering dependable performance in challenging locations.
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Connectivity: Built-in MasterBus, CZone, and NMEA 2000 for broad monitoring and system integration.
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Build, installation, and marine-ready design: The most compact and lightweight in its class; dimensions 22.4 x 14.1 x 6.7 inches; weight 37.5 lb; IP23 protection; humidity protection with conformal coating; marine-grade, E-mark certified; heavy-duty connections.
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Display and safety: LED display for status and configuration; galvanic isolation; IEC protection class I; compliances ABYC A31, UL1236, UL1741, SAEJ1171.
With seamless auto-switching, rapid transfer, and Power Assist, the CombiMaster keeps critical systems powered whether you’re on shore power, using a generator, or relying on battery power. The Smart 3-step+ charging protects battery health and speeds safe charging across chemistries, with the battery temperature sensor and automatic voltage compensation optimizing performance under varying conditions. Built-in MasterBus, CZone, and NMEA 2000 connectivity enables easy monitoring and integration into your marine electrical system, while its compact, rugged construction stands up to demanding environments. This inverter/charger delivers reliable performance and value, keeping your onboard power ready at a moment’s notice.
| Specifications sine wave inverter |
| Nominal DC voltage |
12 V (10.2—16 V) |
| Output voltage |
120 V |
| Output frequency |
60/50 Hz (configurable) |
| Output waveform |
true sine |
| Continuous power at 40 °C / 104 °F, cos phi 1 |
3500 w |
| Peak power (30 sec) |
5250 w |
| Surge power (5 sec) |
7000 W |
| Max. efficiency |
96 % |
| Battery no-load power consumption |
37 W (on mode) / < 1 mA (off mode) |
| Energy saving mode consumption |
20 W |
| Synchronise with mains |
yes |
| Specifications battery charger |
| Input voltage range |
90—140 V |
| Max. input current |
25 A (adjustable) |
| Max. charge current at 40 °C / 104 °F |
200 A at 14.25 V (configurable) |
| Battery temperature sensor |
yes, included |
| Battery voltage sense |
automatic compensation |
| Specifications transfer system |
| AC input |
50 A (switched) |
| AC output |
85 A |
| AC input fuse |
Yes |
| Transfer speed |
10 ms |
| Transfer voltage range |
90—140V |
| Transfer frequency range |
40-65 Hz |
| General specifications |
| Galvanic isolation |
yes |
| Display/read-out |
LED display |
| Dimensions, hxwxd |
22.4 x 14.1 x 6.7 inch |
| Weight |
37.5 lb |
| Compliance |
ABYC A31, UL1236, UL1741, SAEJ1171 |
| Technical specifications |
| Charge characteristic |
UoUo, automatic / 3-step+ for flooded, Gel/AGM and MLI, configurable |
| Recommended battery capacity |
400-2000 Ah (based on gel batteries, may differ for other types) |
| Ground relay |
yes, configurable by means of mechanical jumper |
| Temperature range (ambient temp.) |
-13 °F to 140 °F |
| Cooling |
vario fan |
| Protection degree |
IP23 (vertical mounting) |
| Safety class |
IEC protection class I |
| Humidity protection |
conformal coating, max. 95 % relative humidity, non condensing |
| Protections |
over-temperature, overload, short circuit, high/low battery voltage |
| Power Assist |
yes, supports AC input with power from the battery |
| Power Sharing |
yes, allows you to select AC Input fuse setting |
| MasterBus compatible |
yes |
| CZone / NMEA 2000 compatible |
yes |
