Seem to get over one problem ( caravan mover replaced) and I keep losing a little charge from battery . Bought a multimeter and currently have 12.8 volt whilst connected to EHU . Have just removed mains and will leave until morning to check again . Will take a look on you tube .i know it’s not the alarm as have taken fuse out and for radio. Sensible suggestions please.
The aerial booster box (amplifier) is usually hidden away in a cupboard and can be easily left switched on which can slowly discharge the battery. It's happened to us in the past a few years ago when we haven't been on electric hook up so the generator came in handy at that specific time.
Yes,the aerial amplifier is the likely culprit but you should be getting at least 13.6/7 at your battery if the charger is working properly.
I would suggest you disconnect the battery, turn the charger on and use your multimeter to check the voltage across the leads. You should be getting 13 plus volts. If not you've got a problem with the charger.
Obviously don't allow the leads to touch each other.
DaveS1