The Mastervolt DC Master is a DC-DC charger which is designed to provide quick and safe charge to the service battery, providing stabilised voltage to protect the battery and the equipment it powers. This is a non isolated model which has an electrical connection between the input and the output, making it suitable to applications with negative earthing. It is also compact and efficient, with low heat generation.

Traditionally, a service battery is linked to the starter battery via a charge relay. The starter battery will be located near to the alternator and receives most of the charge current. However the service battery is usually further away. The long cables used to connect it up cause a voltage drop, leading to slower charging, which can result in failing appliances and premature failure of the battery.

Modern, fuel efficient engines are equipped with smart alternators, following regulations such as Euro 5 and Euro 6. Instead of a constant output, smart alternators provide a variable voltage; after a brief charging period, voltage is reduced and the charging stops. Furthermore, the energy produced by regenerative braking leads to voltage peaks. Service batteries coupled in the traditional way will receive hardly any charge and may be damaged by these peak voltages.

To solve these issues, Mastervolt offers the DC Master chargers, which monitors the service battery and compensates the voltage loss. There is no fan so operation of the charger is silent and these units also have 2 minutes of extra capacity, perfect for if you need a quick power boost. The DC Master unit is supplied complete with mounting bracket, screws and fasteners.

General specifications

Nominal output voltage: 13.6 V

Max. output power: 326 W

Nominal output power: 272 W

Max. output current (for 2 min. intervals): 24 A

Continuous output current: 20 A

Nominal input voltage: 48 V

Input voltage range (max.): 40-62 V DC (65 V)

Galvanic isolation: no

Stabilised: yes

Dimensions, Height: 217mm x Width: 87mm x Depth: 50mm (8.5" x 3.4" x 2.0")

Weight: 0.77 kg (1.7 lb)

Compliance: CE, E-mark

Technical specifications

DC consumption: 25 mA

Connections: fast-on

Temperature range (ambient temp.): -25 °C to 80 °C, derating > 30 °C (-13 °F to 176 °F)

Cooling: natural cooling

Protection degree: IP53