So often there is a surplus of battery power in your leisure battery, and this “surplus” goes to waste. With today’s electrical sophistication of the chassis part of the motor home, it’s not surprising that many people fear flat batteries and being stranded, unable to start the engine. Battery Master will help alleviate those worries. Put simply, whenever there is a surplus of power in the leisure battery, Battery Master will take the excess and safely top up the engine battery irrespective of whether the excess is the result of your Solar Charger, a Built-in Mains Charger, or even the natural discharge of the engine battery over a period of time. Battery Master will never allow power from your engine battery to flow into your leisure battery.

Fit and forget solution to flat batteries - to see you through those long winter months or any other extended period when the van is not used.

 Allows vital chassis components (immobilizers, clocks, radio memories, security systems etc) to 'share' the load with the leisure batteries. 
Will allow charging to the engine batteries On-Off mains hook-up. When solar panels are fitted it gives all the batteries (chassis or engine) installed into the motor home a 'solar charge'. 

 The Battery Master keeps your engine starter battery safely topped up by linking it to the leisure battery. Its automatic one-way action will pass a small trickle charge to the engine battery whenever its voltage becomes less than a defined level below that of the leisure battery, so that the engine battery is kept in the best condition for easy starting and a long service life.

The Battery Master will not allow any charge to flow in the other direction, from the engine battery to the leisure battery.

Battery Master addresses an issue which is inherent in the way that modern motorhomes are often equipped and used: the leisure battery gets a lot of attention (naturally since it plays a vital part in running the equipment which keeps you comfortable in the living area) but the engine battery is left to fend for itself when the vehicle is not running.

Your vehicle is likely to be equipped with a hookup, and maybe a solar panel or generator, which keep your leisure battery charged, and you'll probably have instrumentation which monitors the state of charge of the leisure battery. So the leisure battery can cope with long periods when the vehicle is 'parked up' and not being charged from the engine alternator.

On the other hand, the engine battery is quietly being drained by small loads which are drawn by the vehicle's standard electrical system even when the vehicle is not being used, and by self-discharge. If you have added an alarm system for the motor home then that increases the drain and the battery can lose charge quite quickly to a level where starting is jeopardized. Batteries which are allowed to become too discharged without prompt recharging will be permanently damaged. And usually there is nothing to warn you that this is happening, since the vehicle most likely does not have instrumentation to display the engine battery's state of charge.

Battery Master has a maximum charging current of 1.1 amps which is designed to cope with these low-level losses from the starter battery.

Fully waterproof, British made and designed, Battery Master is easy to install and comes complete with instructions.