It wasn’t too long ago that the technology associated with the word fob was relatively unknown. Basically a keyless entry device, the fob has become a staple piece of equipment for most modern cars. With a fob, you can remotely open your car’s doors, trunk, or hatch all with relative ease. You can even call for help by hitting the big red panic button.
The energy needed to power a fob comes from a button battery. As this battery starts to get old, the distance at which the fob can be used shrinks considerably. Keyless entry battery replacement is simple. Typically you just need a coin, though in some cases a small screwdriver is required. Here’s what you do.

1. Check your vehicle’s manual to determine the replacement battery model # for your vehicle. (Rayovac carries CR2016, CR2025, CR2032, CR1616, CR1620, CR1632, and 23A.)
2. If your fob's battery cover is screwed into position, use a screwdriver to remove it. Otherwise, you can simply use a coin, inserting the coin's edge into the slot at the end of the fob and turning it slightly to separate the battery cover from the device.
3. Pry the battery up using your fingernail, checking its orientation before you remove it. Do not use a metal tool, as it could damage the electronic components of the fob.
4. Install the new battery in the same orientation as the old battery.
5. Place the battery cover back into position and press the two halves together until they snap. Voila!
Once you’ve replaced the battery, put some distance between yourself and your vehicle to test its superpowers. If you’ve done it correctly, you should be able to zap open those trunks, doors, and hatches from as far as you could the first time you used the fob. See? Keyless entry battery replacement is a breeze!