battery can be made, sit in a package for years (though not indefinitely), and still be useful when popped into your TV remote or hearing aid or electric car. Though it won’t work forever; the electrolyte solution will get tired, and as one of the metals is slowly eaten away while the other grows heavier, the battery lags and then ceases to work at all. A rechargeable battery reverses the direction of flow, using electricity from an outside source to move most (but not all) of the ions and accretions back to the other side, where they will be ready to flow back again when conditions demand.
