On modern Chevrolet key fobs, the key itself is used as a tool to help you swap out the old battery for a new one.

How To A Program GM Key Fob A key fob, also called a keyless entry remote or keyless transmitter, controls your vehicle’s locks, trunk and alarm from a distance. Every key fob must be programmed to ...

Batteries fade and die over time, but but changing the cell in your Chevrolet key fob doesn't have to be difficult.