Finally in aux mode (twice starting button without brake paddle application) I always turn of the HVAC system and the radio and turn the light switch to off (position below DLR) to reduce battery load.
Buying a trickle charger like from CTEK I recommend when you have a garage as I frequently charge our car batteries to keep them happy and twice a year I recondition the lead acid in the cruiser. It pays off to have one also for many short drives which inevitably seems to happen and cold spells, be it that is only for a week or so per year in Houston and not even seriously cold…