That would depend on the type of battery, and probably also on the ambient temperature.
what type of energy is stored in batteries
electricity is stored in batteries
You should never store batteries in equipment for too long a period as they may leak and destroy the equipment they are powering. This is especially true if the environment they are stored is hot and humid. In a cooler, drier area they might last a bit longer.
Chemically
it is the energy stored in batteries
Batteries are a good example.
Chemical energy is stored in batteries, food, and other molecules. When these substances undergo chemical reactions, the stored energy is released.
Yes, charged batteries are typically heavier than uncharged batteries due to the presence of stored energy in the charged batteries.
Electrical energy can be stored in batteries. Water energy can be stored behind dams.
Yes that's what batteries do.
Chemical Energy.
it is the energy stored in batteries