This has me thinking. I wonder how complicated and effective it would be to use an aluminium frame to thermally connect all the batteries to heat and/or cooling sources? Heat pad on one side of the bank, finned heat sink with fan on the other?
I don't know if it can be done without cooking the one that's in most direct contact... and it'd be a shame if the fan was mandatory to achieve that and for some reason failed.
That's the same thing I'm dealing with and can't for the life me google an answer to, controlling the temperature of the pack (approximately) without roasting them from a bottom heat source. I can keep the alum floor 70*F all day but I'm not terribly interested in the floor temp, more so the BMS and the temp from its probe. But to apply heat based on that is to make the floor potentially a frying pan