Garage door remotes typically use batteries to power their operation. These batteries provide the energy needed for the remote to transmit a signal to the receiver, which opens or closes the garage door. Common battery types used in garage door remotes include 9-volt, AA, and CR2032. Replacing the batteries is a relatively simple process, but it may vary depending on the specific remote model. It is essential to replace the batteries promptly when they start to weaken to ensure the remote functions properly and avoid any inconvenience in operating the garage door.