Batteries contain chemicals that produce electrons. Chemical reactions are known as electrochemical reactions if they produce electrons. Electrons that are formed within the battery collect near the negative terminal. If a wire is connected between the two positive and negative terminals of a battery the electrons will start to flow from the negative terminal towards the positive terminal. This moving of electrons results in the battery wearing down. In larger batteries this can dangerous. It is important that a battery be attached to some load like a motor or a bulb. Once the negative and positive terminals are connected the chemical reactions within the battery start to occur and electrons start to move. A battery will not loose power while in storage as long as the terminals are not in contact with each other.