on our 33 the 2x140 house battery's are on the port side and starter battery on starboard, having them on that side helps to balance out the weight in the locker, we can get a weekend out of them but as symphony2 said the fridge drains quite a lot out of them, if you said 5 amp for 12hrs (running time at 50%) for a 24hr day would take 60ah, add on the other stuff and it soon runs out.