Q Why is my engine battery level low?

My motorhome is a Hymer B578 2014. I have a new engine battery that is six months old.

l have noticed via my Metatrak tracker app, which monitors the battery status, that the voltage drops over four or five weeks to critical even though on electric hook-up. l assumed the mains supply would keep the battery topped up.

Andy Greaves

A Have you actually checked the starter battery voltage with a multimeter?

Just to be sure.

Your Metatrak system does add to the base electrical load on your starter battery when everything is supposed to be turned off; the same applies to many alarm systems as well as trackers, and four to five weeks is in the ballpark for the battery losing power if it is not being topped up by an alternative supply.

I believe your Hymer B578 2014 will have a Schaudt Elektroblock EBL 99. Or perhaps the very similar EBL 100.

The Hymer manual will tell you that ‘the transformer/rectifier (mains charger) charges the living area battery. The transformer/rectifier charges the starter battery with a float charge only’.

A small component within the EBL unit passes a small current to the starter battery once the leisure battery is fully charged. It is very possible that this is now insufficient as you have trackers and alarms also being powered from the starter battery.

The fitting of a Battery Mate or Battery Master should overcome this problem.

The electrical connections for these can all be made at the EBL unit where the battery connections are attached.

The Battery Master or Battery Mate is a small device that has two or three wires. One wire connects to the leisure battery positive, one wire connects to the starter battery positive and, if your device has three wires, then the third connects to the chassis/negative. These are moderate cost, but operate automatically. These will top up the starter battery once the leisure battery is charged either by electric hook-up or solar panels. These units come with full fitting instructions.

Clive Mott