ya, I used to have two 6V batteries in it, then changed to a 280AH LiFePO4, but I put it in the same space as it was a quick upgrade. this year I gave that battery to a friend and I am building a new 304Ah battery for it, but I want it inside the heated space as I do enjoy camoing in the winter also. So this is turning into an all in one powercenter with a built in shelf haha.
Mine lives outside also, but my normal day time temps in the winter are about freezing so its not to bad and a small space heater inside makes it nice enough to do interior projects.