How to Change Battery in Key Fob: A Step-by-Step Guide

Are you tired of experiencing inconsistent performance from your car remote? Does it seem like your key fob’s signal is getting weaker, or worse, it’s not responding at all? One common culprit behind this issue is a dying battery. Unfortunately, many people are unaware they can replace the battery themselves. They may even resort to buying an entirely new key fob instead, which can be costly and time-consuming.

According to Battery University, most key fobs use a lithium coin cell battery that typically lasts between two to four years. However, individual usage patterns can cause the battery to drain faster than expected. When this happens, it’s important to know how to change the battery in your key fob to ensure consistent performance and avoid unexpected lockouts. In this article, we’ll provide a step-by-step guide on how to change the battery in your key fob, so you can get back to using your car remote without any issues.


Key fobs, also known as car remotes, have become a ubiquitous part of modern car keys. These handy devices make it easy to lock and unlock your vehicle, as well as start the engine, without ever having to take your key out of your pocket or purse. But what happens when your key fob stops working? A common reason for this is a dead battery.

Replacing the battery in your key fob is a simple process that can save you time and money compared to buying a new device or taking it to a dealership. With just a few tools and some basic knowledge, you can easily replace the battery yourself and get your key fob working like new again.

In this guide, we’ll walk you through the step-by-step process of changing the battery in your key fob. We’ll also discuss when you should replace the battery, what type of battery you need, and provide valuable insights to help you maintain your car remote in top condition. So let’s get started!

When Should You Replace Your Key Fob Battery?

If you’re wondering when to replace your key fob battery, there are a few telltale signs that it’s time for a new one. One of the most common indicators is a low battery warning, which may be displayed on your car’s dashboard or through a flashing light on the key fob itself. This warning typically appears when the battery has reached a certain level of depletion and needs to be replaced – ignoring it could result in your key fob no longer working at all.

Another sign that you might need to replace your key fob battery is a fading signal. If you find that you have to press the buttons more than once to get your car to unlock or start, it could be a sign that the battery is running low. Over time, the signal from your key fob may become weaker and less reliable, making it more difficult to operate the locks or start the engine.

Inconsistent performance is also a clear indication that your key fob battery needs changing. This can take many forms – for example, you may find that your key fob sometimes works perfectly while at other times it seems to have stopped working altogether. In some cases, the buttons on the key fob might not register any input at all, leaving you stranded without access to your car.

Ultimately, if you think there might be an issue with your key fob battery, it’s always better to err on the side of caution and replace it sooner rather than later. Key fob batteries are relatively inexpensive and easy to replace, and doing so could save you a lot of hassle and inconvenience down the line.

What Type of Battery Do You Need?

When it comes to changing the battery in your key fob, one of the most important things you need to know is what type of battery to use. The good news is that most key fobs use either a lithium ion battery or a coin cell battery, both of which are readily available and easy to find.

Lithium ion batteries are the most common type of battery used in key fobs. They are lightweight, long-lasting, and have a high energy density, which means they can store a lot of energy in a small space. These batteries are also rechargeable, which makes them a more eco-friendly choice than disposable batteries.

Coin cell batteries, on the other hand, are small, flat, and round batteries that are commonly used in watches, calculators, and other small electronic devices. They are also a popular choice for key fobs because they are inexpensive and widely available. Coin cell batteries are typically made of zinc or lithium and can last for several years depending on how often you use your key fob.

When choosing a battery for your key fob, it’s important to check the manufacturer’s specifications to ensure that you get the right size and type of battery. Using the wrong type of battery can damage your key fob, and in some cases, even cause it to stop working altogether.

In summary, whether you choose a lithium ion battery or a coin cell battery, make sure to use the correct size and type recommended by the manufacturer. This will help ensure that your key fob continues to work properly and that you don’t run into any unexpected issues down the road.

Step-by-Step Guide to Changing Your Key Fob Battery

Step 1: Open the Key Fob Cover

To change the battery in your key fob, the first step is to open the cover. The location of the cover might vary depending on the make and model of your car, but it’s usually on the back or side of the fob.

To locate the cover, look for a small indentation or a seam around the edge of the fob. It might be difficult to see, especially if the fob is dirty or worn out. If you can’t find the cover, consult your car manual or search online for instructions specific to your vehicle.

Once you’ve located the cover, the next step is to pry it open. This can be done with a small tool like a flathead screwdriver or a coin, or by using your fingers if the cover is loose enough. Be careful not to apply too much force or you risk damaging the fob.

If the cover is stuck, try gently wiggling it back and forth while applying pressure. You can also try using a lubricant like WD-40 to loosen it up. Just be sure to wipe off any excess oil before replacing the battery.

In summary, opening the key fob cover is the first step in changing the battery. Locate the cover by looking for an indentation or seam, then pry it open using a small tool or your fingers. With this simple task completed, you’re one step closer to having a fully functional key fob.

Step 2: Remove the Old Battery

Once you have successfully opened the key fob cover, you’ll be able to see the old battery inside. The next step is to remove it carefully, without damaging any of the other components of the key fob.

To locate the old battery, look for a small round object that resembles a coin or button cell. It should be visible and easy to access once you’ve opened the cover. In some cases, the battery may be held in place by a clip or a small plastic housing. If this is the case, gently release the clip or remove the housing to gain access to the battery.

Now comes the tricky part – removing the old battery. You can do this either with a small tool or your finger, depending on what’s easiest for you. If you’re using a tool, make sure it’s small enough to fit inside the key fob without causing any damage. A small flathead screwdriver or a pair of tweezers should do the trick.

Carefully wedge the tool underneath the battery and begin to lift it out of its compartment. Be very gentle as you do this, as the battery may be stuck or held in place by a small adhesive strip. If you feel any resistance, stop immediately and reassess the situation.

Alternatively, you could use your fingers to remove the battery. This method tends to be gentler on the key fob and reduces the risk of accidental damage. Simply use your thumb and forefinger to gently pinch the sides of the battery and lift it out of its compartment.

Whichever method you choose, make sure to keep a firm grip on the battery at all times. Once it’s removed, take a moment to examine it closely for any signs of damage or leakage. If the battery looks fine, dispose of it safely and move on to the next step – inserting the new battery.

Step 3: Insert the New Battery

Inserting the New Battery: Ensuring Correct Polarity and Proper Placement

Now that you have removed the old battery, it’s time to insert the new one. However, before doing so, it’s important to check the battery polarity to avoid damaging your key fob.

Most key fob batteries are designed with a positive (+) and negative (-) terminal. These terminals indicate the direction of the electric current flow in the battery. To ensure that the new battery is inserted correctly, you need to check the polarity markings on both the battery and the key fob.

If the battery has no markings, you can look at the inside of the key fob to see the proper orientation. Usually, there will be a small diagram indicating which side of the battery should face up or down.

Once you have checked the polarity, it’s time to insert the new battery properly. Make sure that the battery is clean and free of debris. Then, gently place the battery into the slot with the correct polarity orientation.

It’s essential to make sure that the battery is snug and secure in the compartment. If the battery moves around or isn’t tightly fitted, it can create issues with the key fob’s performance.

Finally, once the new battery is securely in place, you can replace the cover and test the key fob to ensure that everything is working correctly.

By following these simple steps, you can quickly and easily replace the battery in your key fob, ensuring that it continues to work like new.

Step 4: Replace the Key Fob Cover

Replacing the key fob cover is the final step in changing the battery of your car remote. It may seem like a simple task, but it is essential to do it correctly to avoid any issues or damages down the line.

To replace the cover, all you need to do is snap it back into place. However, make sure that it’s secure and doesn’t come off easily. You don’t want to risk losing the battery or damaging the internal components of your key fob.

It’s important to note that some key fobs may have additional features such as buttons and displays that require the cover to be aligned correctly for them to function properly. In such cases, it is crucial to ensure that the cover is snapped back into place precisely.

Before using your key fob again, test it to make sure everything works correctly. If you notice any issues or inconsistencies, double-check the battery installation and cover placement.

In conclusion, replacing the key fob cover is a straightforward but essential step in maintaining your car remote’s functionality. Remember to snap it back into place securely and test it after installation to ensure everything is working correctly.



Replacing the battery in your key fob may seem like a small task, but it can save you time and money in the long run. By doing it yourself instead of taking it to a dealer or mechanic, you not only save on labor costs, but you also gain confidence in your ability to perform basic car maintenance tasks.

DIY key fob battery replacement is an easy and cost-effective way to ensure that your car remote works properly. As we discussed earlier, a low battery can cause issues such as a fading signal and inconsistent performance. These issues can be frustrating and could lead to costly key fob replacements if not addressed promptly.

Car maintenance is an essential part of owning a vehicle, and changing your key fob battery is just one of many tasks you can do yourself to keep your car in good shape. Regularly checking and replacing fluids, filters, and other parts can extend the life of your car and save you money on repairs in the long run.

In conclusion, DIY key fob battery replacement is a simple and effective way to maintain your car’s remote control functionality. It’s a small effort that can make a big difference in keeping your car running smoothly and avoiding expensive replacements. So, next time you get a low battery warning on your key fob, don’t hesitate to grab a new battery and replace it yourself!
After reading this step-by-step guide, you should now have a good understanding of how to change the battery in your key fob. Knowing when and how to replace a dying battery is an essential part of car maintenance that can save you time, money, and frustration in the long run. This DIY solution is a simple yet effective way to keep your car remote working like new, ensuring you never find yourself locked out of your vehicle or struggling with a weak signal. So next time you notice your key fob’s performance starting to fade, don’t hesitate to follow these easy steps and make the necessary battery change. Your car will thank you for it!

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