How to Change the Battery in a Key Fob? – A Comprehensive Guide


Written by

Charles Bolte



Vernon Hoppe 

how to change the battery in a key fob

As a car owner, you’ll have to contend with a few issues with your vehicle once in a while, most likely minor ones you can handle. One of these would be changing your car key fob battery.

A key fob is powered by a small battery inside, and every 3 years or so, it will need replacement to function properly. Read this article and learn how to change the battery in a key fob yourself.

Changing the Battery in a Key Fob


Before cranking open your key fob, it is best to prepare first to change the battery in car key properly.

Here are what you need:

  • Your car manual guide
  • A flathead screwdriver to remove key fob cover
  • A new battery for replacement

Now these are the simple steps:

Step 1: Remove the metal key


Before you open key fob to replace battery, it is best first to remove the metal key attached to it. You can have better access to your old battery and better room to work on it.

While some smart car keys no longer come with a detachable metal component, some car key fobs still have attached metal keys to them.

Step 2. Pry open the key fob through the notch


Perhaps every car owner can admit that the trickiest part in car key battery replacement would be opening the key fob cover.

Indeed, the notch or gaps in some fobs where you’re supposed to split it can sometimes be so tiny that you’ll need a thin and pointy material to snap the cover.

Nevertheless, your flathead screwdriver will be enough to do the job. You can wedge it down on the key fob’s gap through the seam in the middle and work your way around to expose the battery inside.

Step 3: Pop the old battery out


Once the cover is split open, you’ll easily see the small battery in car remote that looks like a coin. You can pop it out with your finger or screwdriver to be removed.

But before doing so, note the orientation and placement of the old battery. Remember what side the positive and negative signs are facing.

Basically, you’ll need to put your new battery just like how your old battery is placed.

Step 4: Insert the new battery


Following the old battery’s identical placement and orientation, put the new battery in key fob to replace the drained power source. The battery holder has a mechanism that automatically holds your battery in.

This tiny power source is usually a cr2032 battery that you can conveniently purchase online or in your local hardware store.

Step 5: Snap the key fob cover back in place


While you may struggle to pry open your key fob cover, closing it up is not a problem. The cover halves automatically snap and lock themselves with just a thumb press.

Once you hear that small click sound, it confirms that your cover is secured.

Step 6: Test the key functions


Of course, to guarantee that you successfully replace battery in key fob, press all the buttons and test whether or not they function individually.

Doing this will ensure that your key fob is now recharged and examine if there is any damage to the other components inside the key fob.

Benefits of Using a Key Fob


Whether you are dealing in key fob Honda or a Mercedes, there are a handful of advantages to using a car key fob. But the most common of them all are convenience and security.

  • Without question, you can open your trunk without going around the back with a single press of the key fob.
  • You can also close the windows and doors simultaneously with just a single click. For security, advanced key fobs today are equipped with smart sensing that automatically locks your vehicles once you are out of range.
  • Keyless entry is also made possible with key fobs, as it allows turning on the car ignition and unlocking it from afar.

Does a Key Fob Have to Be Reprogrammed After Replacing the Battery?

If you only replaced the battery from your key fob, you will likely not need any reprogramming. A simple battery replacement does not do any other change in your key fob besides a recharged power supply.

Reprogramming may be required if you replace other components besides the battery, like wiring and electrical units. Nevertheless, reprogramming is a relatively simple step you can follow.

Frequently Asked Questions


What happens if the key fob battery dies?

When your key fob battery dies, it can no longer send signals to start your machine. A key fob works by commanding the ignition system through a proximity signal.

Other key fobs come with a physical key, so they can still run their car through the metal key when their battery dies unexpectedly. Other cars have different ways of compensating for this event which can be found in the car manual.

How many years does a key fob battery last?

With regular usage, a car key fob battery can survive for 3 – 4 years. While the key fob battery is relatively small, such type remains a reliable power source.

What are the signs of a low-battery key fob?

You can tell when you need to replace the key fob battery when it shows less responsiveness. The low battery also means reduced proximity capacity and harder key fob detection than usual.

Suppose you can spot symptoms of weak function and detection. In that case, it means your key fob battery is nearing its end and already needs a replacement.


Like any other car part, your key fob also needs maintenance. Good thing you don’t need to ask where to get a car remote battery replaced since it is a simple step you can easily follow.

Just make sure you get the necessary tools to open your key fob and the right type of battery to replace. It’s a simple process, so you don’t have to overdo it; if the functions are well, you did it correctly.

With this guide on how to change the battery in a key fob, you can conveniently wrap up your battery replacement in no time!

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