Most of the electronics are subjected to corrosion due to their leaking batteries. I am sure you have all seen corrosion of battery compartments at some point in your lifetime.
It is always better to know the different types of batteries used in your devices. Some types of batteries do leak. Rechargeable batteries like NiMH, NiCd and non-rechargeable batteries like alkaline batteries leak as well.
So, if you are not frequently using these battery-powered devices, do store them separate with batteries removed.