There is no good reason the leave electric on in a shop or even keep it heated when not in use. Oil the tools with any spray on oil.
If the shop is insulated and has only dry vehicles allowed in it then moisture or humidity is pretty low. I have no rusting problems.
Oil film is the key, especially on bare metal. All Li batterys need special outside storage containers. Storing Li batterys in a shop is like having can's full of oily rags, maybe they go up and maybe not. Its a gamble. I'd rather go to a casino to do that it can be cheaper if you set a limit.