[masraum]

Originally Posted by flatbutt

That's what I do for ALL mine and the FD recommends. You must also prevent them from freezing and anything that would damage the separator between anode and cathode.

I've had my M12 batteries in the house, and have always thought it may not be a good idea.

I've always had my Ryobi 18V outside. I keep them plugged in. I assume that means that they've frozen unless having them plugged in keeps them from freezing.