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A Mastervolt system for carefree camping


Application     6-8 metre motor home
Use Generally day trips or weekend trips, at night connected to the grid
Details      Basic appliances

view system drawing

System description

This system is designed for mobile homes, recreational vehicles and commercial vehicles with limited electrical demands or equipment. The system satisfies basic power needs for 12 V lighting, radio/TV/DVD, a satellite dish and a few 230 V devices, such as a laptop, electrical toothbrush and your mobile telephone charger. The heart of the system consists of a sturdy and maintenance-free gel battery. Used normally, the battery will deliver enough power for a full day, independently of the engine alternator or grid voltage. This is especially practical considering the number of locations with no mains hook-up.

Energy consumption

6-8 metre motor home

The basics

  • Battery monitoring for full information on state of charge and time remaining of your batteries. 
  • The maximum AC capacity is 80 watt for the laptop and telephone/tablet charger. 
  • Simple operation via touchscreen control panel. 
  • Complete convenience: With an onboard inverter you and your guests will be able to use the standard phone and laptop adapters.

System choice

A system with separate charger and inverter provides the highest flexibility and reliability. The charger will always provide the optimum charge even when the available grid power is limited, fluctuating or unreliable. The inverter will provide a perfect true sine wave output to your sensitive onboard electronics. Power is available when you need it.

Service battery: MVG 12/85

The total of AC and DC consumers requires around 0.35 kWh. Totally discharging the batteries is not advisable so opt for a maximum of 50 % discharge = 0.7 kWh. Taking into account ease of installation and the amount of standard equipment (such as lighting) we selected a 12 V system. The required battery capacity is 0.7 kWh/12 V = 60 Ah. This makes the MVG 12/85 gel battery the best choice. 

Battery charger: ChargeMaster 12/15-2

In normal conditions we assume 20-25 % of the battery capacity when selecting a battery charger: 20-25 % of 85 Ah requires a 15 A battery charger. In this case the ChargeMaster 12/15-2 is an excellent choice.

You can use two outputs: One for the service battery and one for the starter battery of the engine.

Inverter: AC Master 12/300

The AC Master 12/300 is sized to power all the loads at the same time. 

Monitoring: Masterlink BTM-III

This battery monitor provides an accurate indication of the current, amperage, time remaining and estimated capacity of the battery. The built-in microprocessor calculates the remaining capacity and stores historic data. 

Other system components

System drawing

System 6-8 meter Motor home