Habitation Battery discharging

[ravman]

Hi All,
I have a 82h habitation Battery which was new in Feb 2012. Last week travelled 150 miles, hooked up for next 4 nights with trips from site during day. Travelled home (150miles) battery was flat with control panel showing level at bottom of scale.
Next am checked again not even enough power to illuminate the gauge on control panel.
whilst travelling had fridge on 12v, everything else off. This is not first time it's happened. It seems as if the battery is actually discharging whilst running and not charging. It charges from mains hook up and if left will hold a workable charge for at least a month.
Any idea's

 

[gjh]

12v supply to the fridge when travelling normally comes through a relay from the starter battery, which is kept topped up by the alternator. A fridge pulls around 7 amps from a 12v supply so would soon flatten the leisure battery if that were used to power it.
I would check the wiring to verify which battery is being used for the fridge and change it (or have it changed) if necessary.