The CR battery series is the most popular used in key fobs today, with the CR2032 being the most popular one in fobs. Other versions also include CR 2450, CR 2025, and CR 2016. Each number represents the battery’s diameter, width, and height. For example, the 2032 type has a width of 20mm and a height of 3.2mm. Additionally, the C means it’s a lithium chemistry battery, while the R indicates a round shape.
If you use it normally, key fob batteries generally last between three to four years. However, if you choose to take certain precautions to extend its life, the battery can last for 4 to 7 years.
Here are some examples of key fobs and how long their batteries last:
Smart key fob: These feature a transponder that unlocks your car doors without relying on a key. Generally, the batteries last between three to four years.
Remote key fob: These feature a transponder that unlocks your car doors without relying on a key. Generally, these last between three to four years.
Fobik key fob: A fobik is a remote that serves as a key to start your car’s ignition. These batteries only last for 2.5 years.
How do I know if my key fob needs a new battery?
Failing or bad batteries can become problematic in the long run. These three signs will help you determine if it’s time to replace the key fob battery.
Weak signal strength
The majority of fob keys normally have a 50-feet signal strength range for an SUV or a truck. This feature is often used by car owners who either wish to lock or unlock their vehicle’s doors. However, the fob’s transmitter range and strength will decrease once the battery starts dying. If your key fob does not lock or unlock your car, then it will need a replacement. Some automobiles feature an automatic start button, allowing you to start the engine through the key fob. If this doesn’t start on time, then it could also mean that you will need to replace the fob’s battery.
Key fob operates inconsistently
Key fobs normally become active after pressing a button, indicating proper functionality. There are newer types that start the ignition system. These are typically placed inside a dashboard slot, or the fob transmits an electronic signal to the vehicle’s ECU. From there, a driver can press the start button. Inconsistent operation of this feature means that the battery is wearing out.
Unlocking doors requires several clicks
A single click is usually all it takes for a key fob to unlock your vehicle’s doors. Sometimes it may need a few extra clicks. If that’s the case, then it’s a sign that the battery is failing, and it will need to be replaced before it completely dies.
It’s important to note that you should not completely drain your key fob battery because it could reset the sensors. If that happens, they won’t be able to connect with your car.
Tips to make your key fab battery last longer
Although the battery certainly won’t last forever, it can wear out after a few years. Practicing the tips mentioned below will help extend your key fob’s battery life.
Power saving mode: Some key fobs come with a power-saving mode feature that helps to keep your battery running longer. It works by preventing the fob from receiving or sending radio waves. However, this is only available on vehicles that have a push start button.
Storage: Leaving your fob in the car overnight will also cause it to draw in the battery due to signal transmission. The same applies if you put it on a hook near the vehicle. Instead of using those approaches, you should store it at least 10 feet away from your car, where the vehicle’s computer signal can’t read the fob.
Direct sunlight: Placing your key fob in direct sunlight may shorten the battery life due to heat build-up. For best practice, keep it in a shady or cool area.
Humid environment: Exposing the key fob in a humid environment can impact the battery. It’s best practice to place it in an area where the humidity is low, keeping it safe from damage.
How to replace a key fab battery
Replacing the battery in your key fob is relatively simple. You will first need to find out if it’s a rechargeable battery. That’s because a rechargeable battery, like the VL2020, requires additional tools for the replacement process. If this proves to be the case, you may need a soldering iron, which removes the battery from the circuit, and super glue to attach put it in place. Otherwise, you will need a flathead screwdriver and a replacement battery.
First, inspect your key fob to find the notch, which opens the unit. That will either be in the small gap at the top or around the connection point where the key can be removed. Next, grab your screwdriver, place the tip into the notch, and pry it open. This will cause the fob to open up in half, showing the circular battery.
Once you see the battery, you will need to determine its type. To do this, inspect it closely, keeping an eye out for the markings that indicate the battery’s model. You can also look in your owner’s manual for this. After determining the type, purchase a replacement.
Next, use your finger to remove the battery by popping it out and place your new battery where the old one was integrated. With the new battery in place, you can put the key fob back together by squeezing both ends together. Fortunately, you will only need to replace the battery once every 4-7 years, so this won’t be a regular project.
Should you replace a key fab battery yourself?
Although it may seem a bit challenging due to uncertainties and the risk of damaging the key fob during the process, you can still replace it yourself. However, taking this route could lead to improper handling, damaging the fob if you don’t have the proper tools or knowledge to perform this task. As a result, the damage could make it inoperable.
Additionally, some fobs have a tiny case screw containing a unique head that could peel off if the right tools aren’t used. If this happens, then you will not be able to remove the battery cover, which means you will need to buy another unit.
You may also need to take it to a dealership if you’re able to replace the battery, but the fob doesn’t work after putting everything back together. That’s mainly because some fobs must be reprogrammed with a computer to work with your specific vehicle.
How much does it cost to replace a key fob battery?
Replacing a fob battery yourself is rather inexpensive. It only costs between $3.70 – 9.00, plus tax. However, this depends on the fob type. If you have a special fob, then you will need to go to a car dealership that sells the special battery types. Some dealerships allow you to pay just for the battery, which means the labor is free. Otherwise, it won’t cost a lot for a dealership to replace the battery. Some shops offer these services for just $9.75.