Learn how to replace your car key battery in a few simple steps.
The car key is an essential part of a driver’s daily life. Whether it’s unlocking the doors or starting the engine, it plays a crucial role. However, like any electronic device, the car key battery can run out over time.
Knowing when and how to change a car key battery is a useful DIY skill that can save you a lot of trouble. In this article, we explain every steps neccessary, how to do it, give you tips to maximize your battery’s lifespan, and also give you an extra gift you can attach to your key.
What are the signs of a low car key battery?
To avoid wasting time, it’s essential to ensure that your car key’s malfunctions are indeed related to the battery. Therefore, we’ll first learn to recognize the symptoms of a dead battery.
1. Reduction in range:
One of the first signs of a low battery is a decrease in your key fob’s range. You’ll notice that you need to get closer and closer to your car for the central locking system to work. Sometimes, you’ll even have to stand right next to the vehicle to lock or unlock it.
This symptom may seem harmless, but motorists accustomed to unlocking their car remotely are more likely to be exposed to theft without realizing it.
2. Difficulty locking or unlocking the car:
A dead battery can also cause your key to work intermittently. You might find that the key works sometimes, but not always. You press the lock button, but nothing happens. You try several times, and eventually, it works. This type of problem is not only annoying but can also leave you in a difficult situation if you can’t lock your car in a safe location.
However, make sure that this problem isn’t caused by a damaged button due to a faulty key. In that case, changing the battery won’t solve your problem!
3. Warning message on the dashboard:
Some modern vehicles are equipped with a key fob battery monitoring system. When the battery gets low, a warning message appears on the dashboard, prompting you to replace the battery. This warning should not be ignored, as it indicates that the key fob may soon malfunction.
4. Keyless entry system that no longer detects the vehicle:
If your car is equipped with a keyless entry and start system, a low battery can disrupt communication and prevent a smooth transmission between the key and the vehicle. You may notice that you need to get very close to the car, or even touch the door handle, for the system to detect the key.
In some cases, starting the engine may even be impossible. If this happens and you absolutely need to start your car, place your key as close as possible to the “Start and Stop” button to minimize the distance to the receiver.
Following these steps will not only save you time and money but also prevent you from breaking your key.
1. Identify the key type:
Before you even begin to open your card, remote control, or car key, it’s important to identify the type and model. The methods and recommendations will depend on this and will prevent you from attempting a battery change that could go wrong.
The “classic” key
Classic keys include all keys with a non-retractable blade. They generally lack a hands-free function and must be inserted into the ignition.
Changing the battery on these keys is easy in almost all cases. You simply need to unclip the casing or unscrew a screw.
You can refer to the examples below:
The “flip” key
Flip keys have a retractable blade that extends from the key at the push of a button. They are convenient and take up less space in pockets, but this feature makes changing the battery more complicated.
This retractable blade works thanks to a spring held in place by the key casing. If the casing is not opened correctly, the blade and spring can become detached and sometimes be impossible to reattach.
Although some of these keys have a clip-on compartment on the back for battery replacement (such as Hyundai, KIA or Mercedes keys), we recommend that you use a professional for battery replacement on these models.
To determine if you have a flip key, you can refer to the examples below:
The remote control or hands-free key
These models are the most modern and more specialized than previous ones. Indeed, this type of key presents fewer risks when opening the lock, but does not make changing the battery any easier.
Some of these keys recharge while driving (BMW, for example), so manufacturers don’t plan for battery replacement and sometimes attach the battery directly to the circuit board. Others, of course, have a slot on the back for battery replacement, but this will depend on the model and brand.
If you have any doubts, we also advise you to consult a professional car key specialist.
To find out if you have this type of key, you can refer to the examples below:
2. Gather the necessary tools:
Changing a car key battery requires only a few tools. You will need:
– A flathead or Phillips screwdriver, depending on your key model.
– A key fob opening tool (recommended): To open your key fob casing easily.
– A small pointed object: Like a butter knife or a toothpick to open the casing (if you don’t have a key fob opening tool).
– A new battery: Choose one according to the instructions or your old battery.
– A soft cloth: To protect the key from scratches.
3. Open the key fob case:
Locate the slot on the case and carefully insert the flathead screwdriver or case opener. Pry gently to avoid breaking the plastic.
4. Remove the battery:
Once the case is open, locate the battery. It is usually held in place by a small clip or tab. Use a non-metallic object (like a toothpick) to gently remove it.
5. Insert the new battery:
Insert the new battery into the compartment, respecting the orientation noted previously. Make sure it is securely fastened and does not move.
Next, carefully replace the two casing parts and press until they click into place. If your wrench is held in place by screws, tighten them gently to avoid damaging the casing.
6. Test the key’s functionality:
Once you’ve successfully replaced the battery, test your key to make sure it works properly. Try unlocking the doors and starting the car.
If that doesn’t work, check that the battery is properly inserted.
Who can change the battery in a car key?
As mentioned previously, depending on your key type, you may need professional help. If you don’t want to replace your key’s battery yourself, here is a list of professionals you can contact:
1. Car dealerships:
Car dealerships typically offer a key maintenance service. By going to a dealership, you’re guaranteed a replacement that meets the manufacturer’s specifications. However, this service can be more expensive than other options.
2. Garages and car repair shops:
Some garages, particularly those specializing in automotive electronics, can replace the battery in your key. This service is often faster and less expensive than going to a dealership.
3. Automotive locksmiths:
Automotive locksmiths are an excellent option. In addition to offering key duplication and programming services, they can also replace your key’s battery in minutes. They usually carry the correct batteries and can advise you if your key is malfunctioning.
4. Multi-service shops and shoe repair shops:
Some shoe repair shops and general stores offer battery replacement services. These professionals, often located in shopping centers, offer a quick, affordable way to change your battery without an appointment.
Where can I find and buy a car key battery?
If you need a replacement battery, you need to visit a local automotive store or a specialist key shop. These shops usually have high-quality batteries in stock, specifically designed for car remotes.
When buying, always double-check the battery model number (e.g., CR2032 or CR2025) and choose a reputable brand. It’s a small purchase, but using the right battery makes a big difference in how consistently your key performs.
A Small Upgrade for True Car Enthusiasts
If your car key is what you use every day and can’t do without, you can make it more interesting by adding a little flair.
The Movable 4 Cylinder Engine Keychain is more than just a place to hold your keys. It’s a miniature engine model with moving pistons that rise and fall, replicating the motion of a real engine.
It is a 3D-printed keychain made from a special material that won’t scratch the key fob or dashboard. It is pocket-friendly in size, durable, and built to last. Whether you’re a mechanic, a driver, a motorist, or simply someone who loves automotive design, it’s one of those subtle touches that makes your key feel personal.
After all, if you’re already taking care of your key by replacing the battery properly, you might as well give it something worthy to hang on to.
