That is easily the worst part of taking advantage of solar - carrying those dang batteries back and forth and then maintaining them. They become like your additional adopted children. They can't be frozen so they need to be stored in a warm place, their charge needs to be regularly topped up when not in use . They're heavy and potentially dangerous (as an old tank commander who was scared of almost nothing told me: always wear goggles when charging & connecting them).
Batteries are the dirty little secret of solar power.