Dead Key Fob? Here’s How to Fix It Fast

Almost every vehicle on the road today uses some form of key fob technology. A key fob is a small electronic remote that uses a radio frequency to perform various functions on a vehicle, such as locking, unlocking, and arming the alarm. Think of it as a TV remote for your car.

As vehicle technology has advanced, so have the form and function of key fobs. Many now offer features such as remote engine start or the ability to activate automated features on the vehicle. The modern key fob has nearly replaced the traditional keys altogether.

As with most modern conveniences, key fobs occasionally need a bit of maintenance—most commonly, replacing a dead battery. This task can seem intimidating to some drivers who assume it's more complicated than it really is.

The reality: Since a key fob is just a fancy remote—like a garage door opener, TV remote, or electronic toy—its batteries are pretty simple to replace. With the right battery and a few basic household tools, you can swap it out in just a few minutes, without the need for a trip to the car dealership.

Here, we show you how easy it is to change your own key fob battery using standard Dodge Grand Caravan and Hyundai Santa Fe key fobs as examples.

Step 1: Identify your key fob's battery.

Using an online resource such as Keyless Entry Remote Inc. or Batteries Plus, drivers can quickly and accurately identify the type of battery used in their specific make and model key fob. It's important to do this first as there’s nothing worse than realizing you've bought the wrong battery after taking your key fob apart.

In our examples, both key fobs use CR2032 batteries, one of the most common sizes. Other common types include: CR2025, CR2016, CR2450, CR1616, and CR1620.

Step 2: Gently open your key fob.

Every key fob opens a little differently, but the general process is the same. If your fob’s key unfolds (as with the Hyundai Santa Fe), open it to locate the seam where the cover comes off. Using a small flathead screwdriver or even your thumb, carefully pry the backing apart with gentle pressure. Be sure not to use too much force because you could crack the case or damage the key fob.

Step 3: Photograph and replace the battery.

Once the case is open, take a quick photo of the old battery before removing it. It might seem unnecessary, but it’s a great reference as many fobs don’t have clear polarity markings inside. You don’t want to put everything back together only to discover the battery is in backwards.

Step 4: Put your key fob back together.

With the new battery installed correctly, snap the cover back into place. Test your key fob to make sure it works before clicking everything fully into place.

Additional tips

• Avoid touching the electrical contacts or internal components. Circuit boards, transistors, and the antenna are delicate. Damaging any of them may cause your key fob to stop working. If you notice rust or battery residue on the contact points, gently wipe it away with a soft cloth or cotton swab.
• Also, try not to touch the new battery’s flat surfaces with your fingers; skin oils can affect conductivity and shorten its life.
• Don’t force the case open or closed. A little pressure is normal, but too much can crack the casing or snap the clips, leading to an expensive replacement.
• When you’re done, don’t toss the old battery in the trash. Button-cell batteries can be hazardous if swallowed, so recycle them safely at a local electronics or battery recycling center.

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Yes, changing your own key fob battery is just that easy! With a little care and the right battery, the whole process takes just a few minutes—and can save you a trip to the dealership and the expense that comes with it.

While every model varies slightly, most follow this same process—allowing you to have your key fob working like new in no time.