Hi, we’ve only used our T6 camper for short journeys recently and the leisure battery now seems completely dead. The Sargent unit beeps constantly when on and even when driving. Doesn’t seem to be resolved by leaving on hookup for several hours. So, wondering whether it is possible to get to leisure battery and test with multi-meter and/or stick a trickle charger on it or similar. The van has a dc to dc unit which we’ve tried turning on and off and have checked main fuses. Nothing has helped. Interestingly, our diesel heater control won’t turn on either although guess that might be powered by leisure battery. Any advice would be appreciated as we’re now stuck as to what to try next. Also newbies so apologies if any of this should be obvious!