My ageing gel bank (nominal ~400Ah, 12V, ~7 years old) is in my shed, standing on and surrounded by ~2cm of expanded polystyrene.
However, I'd like to keep temperatures and capacity up, and temperatures here have started dropping (down to 8C last night, bank down to ~13C, with air unlikely to get much below 0C in the shed even mid-winter).
I was toying with the idea of covering/wrapping the top and exposed sides/edges of the batteries with a layer or two of bubble wrap to keep cold air from getting to them to help them stay a bit warmer.
My batteries shouldn't be gassing, and nothing will be really air-tight, so:
a) Is there any harm in what I propose?
b) Will it help at all?
I do have a remote probe from the controller already on a (+ve) battery post; that would stay on, under the wrap.