<span class="highlight">Battery</span> drain

Morning all,
I have a duel battery system isolated by a redarc. I have just tossed a 105a/h deep cycle battery that last just over 12 months. I put this down in part to never properly charging the battery - until now I have never had a proper battery charger and relied on the redarc and a small solar system - obviously never properly charged the battery and terminally damaged it in the process. Anyway I have put in a new century marine 100a/h battery and now have a CTEK charger to ensure it is fully charged after a work out - all works well and all good. To preserve the life of the battery I thought I'd disconnect the redarc, figuring that months of around town travel with short bursts of charge can be no good for the battery. So I've just disconnected the redarc from the starting battery so the duel battery is 'isolated' but still connected to the redarc. I fully charged the duel battery the other day but I'm confused with some battery drain. It was at 12.80 the other day and is now down to 12.66 - averaging about 00.04 v loss a day approx I'd guess. Connected to the duel battery I have two separate 8 b&s gauge leads to anderson plugs (front and rear but not connected to anything), a 8 b&s lead to the rear for the fridge (fridge not plugged in) and a 8 b&s lead to a permanently mounted 300 w inverter & UHF in the cabin (both turned off) and the 8 b&s lead to the redarc. Sorry for the rambling but basically are these things still draining the battery even if they are not connected to anything or accessories turned off??? I guess I need to simply disconnect everything at the battery but just curious, thanks and have a good w'end all. Qldrrr