Your car key fob, like any other battery-powered device, can die at any time. Fortunately, these batteries are simple to replace.

 Newer vehicles include a key fob of some kind, either as a separate device attached to your keyring with buttons to lock and unlock your vehicle, or as an integrated part of the key itself. These fobs function on battery power and send a wireless signal to your automobile to control it. Though batteries can survive for two to five years or more, if the battery in the fob is weak, you may be unable to enter the vehicle or remotely start it (one of many possible secret uses for your key fob). The good news is that replacing a key fob battery is straightforward. Here's a step-by-step tutorial for replacing the battery in your key fob.

Look for the Battery Type Embossed in the Plastic

The battery type will be printed on the outside of some key fobs. This manner, you can go to the store and choose your battery before opening the fob. Duracell, Energizer, and Panasonic are three of the most common key fob battery brands.

Look for the Seam Where the Halves of the Fob Come Together

The majority of key fobs open in a clamshell shape, with two parts snapping together. There will be a seam where the two pieces can be separated—there may even be a notch at that seam. If your automobile still requires you to insert the key into the ignition switch, make sure you don't hang anything other than the fob from that keyring; the weight of your house keys can wear down the ignition cylinder, which can be dangerous.

Gently Pry at the Seam or Notch

There is only one tool required to change the battery in your key fob. To open the fob down the middle, gently pull apart the two halves using a small, thin flat-bladed screwdriver (or, in some cases, a firm fingernail). Most cars with key fobs and transponder keys will not allow you to lock your keys inside the vehicle, but you should be prepared in case the worst happens. (By the way, if you have a habit of misplacing your keys, this key finder can assist you.)

Look at the Battery Orientation (Positive and Negative Ends)

The battery will often resemble a little coin and will be labeled with the battery size as well as a plus and minus sign. Take careful note of the battery's orientation. Once you've acquired a replacement battery of the same size, it must be installed in the same manner.

Pop the Old Battery Out and Place the New Battery in

Normally, the battery will pop out with the press of a finger—if you're having difficulties, that flat-bladed screwdriver will come in handy. Insert the new battery with the plus and minus indicators in the same orientation.

Snap Your Key Fob Shut and Test the Fob Function

Assembly is the inverse of disassembly—reassemble the fob and test the buttons. Everything should be like new!

Now that you know how to replace the battery in your key fob, find out about the strange automotive features you may not be aware of.