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Mass Combi 12/2500-100 (120 V)

The Mastervolt Combi literally ‘combines’ an advanced battery charger and silent-running inverter in one remarkably compact device. But that isn’t all: it also adds extra functionality. This includes Power Assist, system paralleling and secondary battery charging. This makes the Combi your ideal solution for a wide range of needs, from low power recreational use right up to full-on, high power industrial applications.

Versatility in power supply

Every model of the Mastervolt Combi is highly versatile, so using one greatly simplifies installation. This single product not only brings you fast and complete charging of your starter and service batteries, it also provides a silent, robust and clean AC power supply. Multiple AC outputs allow heavy-draw items to be separated from the most critical equipment, making sure they don’t unintentionally deplete your batteries. The AC inputs facilitate both mains and generator connections, which the Combi can support with additional power if your loads require more than either can provide. Essentially, just this one product can handle all the power requirements in an autonomous system. 

Modern technology

The unique design of the Combi range is typically Mastervolt. Rather than installing heavy transformers, you can use our high-frequency technology for major benefits in terms of compact size, a lightweight chassis and silent running (there is no transformer hum). 

Perfect in a MasterBus system

Designed for system compatibility, the Mastervolt Combi fits perfectly into a MasterBus system. The network will allow you to easily control and monitor your product, while also optimising the configuration to your needs. In addition, the internal communication between other MasterBus products in your system can even boost the overall electrical performance.

Benefits of the Mass Combi

  • Compact, lightweight and no hum thanks to HF technology.
  • High yield and more power from your batteries.
  • Intelligent 3-step+ battery charger with low DC ripple current for fast charging times and long battery life.
  • Charges two individual battery banks simultaneously.
  • Quiet, powerful inverter with 200 % peak power.
  • Power Assist: extra power assistance from the batteries in case of limited grid or generator power (prevents blown fuses).
  • Pure sine wave energy prevents failures and damage to sensitive equipment such as adapters.
  • Dual AC outputs to separate critical equipment from heavy loads.
  • Higher yields possible via parallel switching (only 2500 W models).
  • Professional connections ensure fast installation and operational security.
  • CE approved and E-marking for mobile applications.

Product code: 37012505
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Specifications sine wave inverter
Nominal DC voltage 12 V (10-15 V)
Output voltage 120 V (± 5 %), adjustable 90-135 V
Output frequency 60/50 Hz (± 0.05 %), configurable
Output waveform true sine, Thd < 2.5 % under standard conditions
Continuous power at 25 °C / 77 °F, cos phi 1 2500 W
Max. peak load 4000 W
Max. efficiency ≥ 90 %
Max. ripple on DC (battery at full load) < 5 %
No-load power consumption on DC (ON/inverter OFF/OFF/energy saving) 9 W / 0.1 W / 0 W / 0.5 W
Parallel configuration yes, up to 2 units
3-Phase configuration no
Synchronise with mains/generator yes
Specifications battery charger
Input voltage range 90-135 V
Max. input current 14.5 A
Max. charge current at 25 °C / 77 °F 100 A at 14.25 V, adjustable
Secondary charger output voltage 12 V
Secondary charger output current 5 A
No-load power consumption on AC < 15 W
Battery temperature sensor yes, included
Battery voltage sense automatic compensation
Specifications transfer system
AC input 1 50 A (25 A switched, to short break output)
AC output 1 35 A (short break output)
AC output 2 50 A (power output)
AC input fuse yes, resettable
Transfer speed half seamless (25 ms max., 10 ms typical)
Transfer voltage range 90-135 V
Transfer frequency range 45-65 Hz
General specifications
Display/read-out LED display
Dimensions, hxwxd 496 x 318 x 156 mm
19.5 x 12.5 x 6.1 inch
Weight 11 kg
24.3 lb
Approvals CE, ABYC
Technical specifications
Charge characteristic 3-step+ (IUoUo, fully automatic), Equalize
Battery types AGM/gel/MLI/flooded/spiral/traction
Recommended battery capacity ~ 200-600 Ah (based on gel batteries, may differ for other types)
Ground relay yes, configurable
Temperature range (ambient temp.) -25 °C to 60 °C, derating > 25 °C
-13 °F to 140 °F
Protection degree IP23 (vertical mounting)
Safety class IEC protection class I
Humidity protection conformal coating, max. 95 % relative humidity, non condensing
Protections over temperature, over load, short circuit, high/low battery voltage
Cooling maintenance-free vario fans
Power Assist yes
MasterBus compatible yes, in combination with a MasterBus Combi Interface



MasterAdjust Software to configure, monitor and log your Mastervolt system (MasterBus-USB interface...



Mass Combi 12/2500-100 (120 V)

RRR type approval



Mass Combi 12/2500-100 (120 V)

RMRS Certificate Mass Combi (Ultra)


Installation manuals

Mass Combi 12/2500-100 (120 V)

Quick installation guide Mass Combi 120V (English)


User manuals

Mass Combi 12/2500-100 (120 V)

Manual Mass Combi 120 V


Product notifications

Mass Combi 12/2500-100 (120 V)

Mass Combi CZone™ Configuration Instructions


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