If the remote key for your Mercedes-Benz has become unresponsive or its range has diminished, it may be time to replace the battery. While this task may seem daunting at first, it is actually a relatively simple procedure that can be completed in minutes with the right tools and a bit of patience.
First and foremost, you will need to gather the necessary tools. You will need a new CR2025 battery, a small flathead screwdriver, and a small Phillips head screwdriver. Once you have gathered your tools, you can begin the replacement process. Start by locating the small access hole on the back of the key. Insert the flathead screwdriver into the hole and gently pry open the key.
Once the key is open, you will see the battery. Use the Phillips head screwdriver to remove the screw that holds the battery in place. Then, carefully remove the old battery and insert the new one. Be sure to insert the new battery with the positive side facing up. Once the new battery is in place, replace the screw and close the key. Your key should now be working properly.
Identifying the Battery Location
Step 1: Locate the Key Fob’s Release Button
On the back of the key fob, you’ll find a small release button. Usually, it’s located near the top or side of the fob. Gently press and hold this button.
Step 2: Separate the Key Fob
As you hold the release button, gently pull the two halves of the key fob apart. You might need to apply some gentle force to separate them completely.
Step 3: Find the Battery
Once the key fob is open, the battery will be visible inside. It’s usually a small, round or rectangular piece located within a battery compartment. Gently remove the battery from the compartment.
Common Battery Types
Mercedes-Benz key fobs typically use the following battery types:
| Battery Type | Shape | Voltage |
|---|---|---|
| CR2025 | Round | 3V |
| CR2032 | Round | 3V |
| CR2320 | Round | 3V |
| CR2450 | Round | 3V |
Preparing the Key
The first step in changing the battery in your Mercedes Benz key is to gather the necessary tools. You will need a small Phillips head screwdriver and a new CR2025 battery. Once you have your tools, you can begin the process of preparing the key.
To prepare the key, you will need to remove the key blade from the fob. To do this, simply insert the screwdriver into the small hole on the side of the fob and gently pry the key blade out.
Once the key blade has been removed, you will need to locate the battery compartment. The battery compartment is typically located on the back of the fob, and it is usually held in place by a small screw. Use the screwdriver to remove the screw and open the battery compartment.
Now that the battery compartment is open, you can remove the old battery and insert the new one. Be sure to insert the new battery with the positive side facing up.
Once the new battery has been inserted, you can close the battery compartment and screw it back into place. Finally, reinsert the key blade into the fob and you are finished.
Removing the Key Blade
To remove the key blade, insert the screwdriver into the small hole on the side of the fob and gently pry the key blade out. Here are some additional tips for removing the key blade:
- Be careful not to damage the key blade or the fob when prying it out.
- If the key blade is difficult to remove, you can try using a small amount of WD-40 to loosen it.
- Once the key blade has been removed, be sure to keep it in a safe place so that you can reinsert it later.
| Step | Action |
| 1 | Gather the necessary tools. |
| 2 | Remove the key blade from the fob. |
| 3 | Locate the battery compartment. |
| 4 | Remove the screw and open the battery compartment. |
| 5 | Remove the old battery and insert the new one. |
| 6 | Close the battery compartment and screw it back into place. |
| 7 | Reinsert the key blade into the fob. |
Removing the Key Battery
1. Locate the key battery compartment on the back of your Mercedes-Benz key.
2. Insert a small flathead screwdriver or a key into the notch at the bottom of the compartment and gently pry it open.
3. Remove the old battery from the compartment. Note the orientation of the battery and ensure that you insert the new battery in the same direction.
Detailed Steps for Removing the Key Battery:
| Step | Description |
|---|---|
| 1 | Identify the small notch at the base of the key battery compartment. |
| 2 | Carefully insert a flathead screwdriver or a spare key into the notch. |
| 3 | Gently pry the compartment open, avoiding excessive force to prevent damage. |
| 4 | Locate the old battery within the compartment and note its orientation. |
| 5 | Use tweezers or your fingers to remove the old battery, ensuring safe handling of the discarded battery. |
Installing the New Battery
Once you have removed the old battery, it’s time to install the new one. Here’s how:
- Clean the battery contacts. Use a clean cloth or cotton swab to gently clean the battery contacts inside the key fob. This will help ensure a good connection.
- Align the battery. Make sure the positive (+) and negative (-) terminals of the new battery are aligned with the corresponding terminals inside the key fob.
- Insert the battery. Carefully insert the new battery into the key fob, making sure it fits snugly but without excessive force. The battery should lock into place.
- Close the key fob. Once the battery is installed, close the key fob and press on the buttons to test the functionality. If the buttons work, the battery is correctly installed.
Here’s a table that summarizes the steps for installing the new battery:
| Step | Description |
|---|---|
| 1 | Clean the battery contacts. |
| 2 | Align the battery. |
| 3 | Insert the battery. |
| 4 | Close the key fob and test the buttons. |
Reassembling the Key
Now that you’ve successfully replaced the battery, it’s time to reassemble the key. Here’s a step-by-step guide to help you with this process:
- Align the two halves of the key: Hold the two halves together, making sure that the buttons and the key blade are aligned.
- Insert the key blade: Push the key blade into the slot on the other half of the key until it clicks into place.
- Tighten the screw: Locate the screw on the back of the key and tighten it securely using a small screwdriver.
- Close the housing: Fold the other half of the key over the first half, ensuring that the housing closes completely.
- Test the key: Press the buttons on the key and test its functionality by inserting it into the ignition and starting the car.
After completing these steps, your Mercedes-Benz key should be fully functional again. If you encounter any issues during the reassembly process, consult the vehicle’s user manual or seek assistance from a qualified mechanic.
Additional Tips for Reassembly:
- Use caution when handling the key blade, as it can be sharp.
- Tighten the screw securely, but avoid overtightening to prevent damage.
- If the key does not work properly after reassembly, check the battery contacts to ensure they are making good contact.
- If the problem persists, you may need to replace the key battery or seek professional assistance.
Testing the Key
Before replacing the battery, test the key to ensure that the problem lies with the battery and not other issues with the key or vehicle. Follow these steps:
1. Ensure that the key is in close proximity to the vehicle, within a few feet.
2. Press and hold the lock button on the key. Hold it for a few seconds.
3. Observe the vehicle’s response. If the doors lock and unlock without any issues, the key is likely functioning correctly, and the problem may not be with the battery.
4. If the doors do not respond, or if the response is inconsistent, proceed with the steps below to replace the battery.
5. If you have a spare key, try using it to operate the vehicle. This will help determine if the issue is specific to one key or a more general problem with the vehicle’s key system.
6. Check for any physical damage or corrosion on the key. Look for any cracks, scratches, or dents that may affect the key’s functionality. Clean the key with a soft cloth to remove any dirt or debris.
Replacing the Key Battery
Locate the key’s battery compartment. It’s usually at the bottom of the key or on its side. Open the compartment using a small screwdriver or key.
Remove the old battery and insert the new one, making sure the positive (+) and negative (-) terminals are aligned correctly.
Close the battery compartment and test the key to ensure it’s working properly.
Reprogramming the Key if Necessary
If the key doesn’t work after replacing the battery, it may need to be reprogrammed. Here are the steps:
Insert the key into the ignition and turn it to the “ON” position (without starting the engine).
Wait for the “INSERT KEY” message to appear on the instrument panel.
Press and hold the “UNLOCK” button on the key for 5 seconds, then release it.
Press and hold the “LOCK” button for 5 seconds, then release it.
Turn the key to the “OFF” position and remove it from the ignition.
The key should now be reprogrammed and working properly.
Troubleshooting Common Issues
The key fob is not working after replacing the battery.
If the key fob is not working after replacing the battery, there may be a problem with the key fob itself. Try cleaning the contacts on the key fob and the battery with a cotton swab dipped in rubbing alcohol. If that doesn’t work, you may need to replace the key fob.
The key fob is not able to unlock or lock the car.
If the key fob is not able to unlock or lock the car, there may be a problem with the car’s receiver. Try moving closer to the car and try again. If that doesn’t work, you may need to replace the car’s receiver.
The key fob is not able to start the car.
If the key fob is not able to start the car, there may be a problem with the car’s ignition system. Try starting the car with the key. If that doesn’t work, you may need to replace the car’s ignition system.
The key fob is not able to open the trunk.
If the key fob is not able to open the trunk, there may be a problem with the car’s trunk release mechanism. Try opening the trunk with the key. If that doesn’t work, you may need to replace the car’s trunk release mechanism.
The key fob is not able to close the windows.
If the key fob is not able to close the windows, there may be a problem with the car’s window motors. Try closing the windows with the key. If that doesn’t work, you may need to replace the car’s window motors.
The key fob is not able to adjust the seats.
If the key fob is not able to adjust the seats, there may be a problem with the car’s seat motors. Try adjusting the seats with the key. If that doesn’t work, you may need to replace the car’s seat motors.
The key fob is not able to control the climate control system.
If the key fob is not able to control the climate control system, there may be a problem with the car’s climate control system. Try controlling the climate control system with the key. If that doesn’t work, you may need to replace the car’s climate control system.
The key fob is not able to control the audio system.
If the key fob is not able to control the audio system, there may be a problem with the car’s audio system. Try controlling the audio system with the key. If that doesn’t work, you may need to replace the car’s audio system.
Safety Precautions
1. Ensure that the vehicle is in park and the engine is turned off.
2. Locate the key fob’s emergency key by pressing the button on the side of the fob.
3. Use the emergency key to open the trunk of the vehicle.
4. Locate the battery compartment inside the trunk, usually behind a small panel.
5. Open the battery compartment by pressing the release button or sliding the cover.
6. Remove the old battery from the compartment.
7. Insert the new battery into the compartment, ensuring that the positive (+) and negative (-) terminals are facing the correct direction.
8. Close the battery compartment and secure it.
9. Test the key fob to ensure that it is working properly by pressing the lock and unlock buttons and checking the response of the vehicle’s locks. If the key fob is not working, repeat steps 1-8 to ensure that the battery is correctly installed and the compartment is properly closed. Additionally, check the battery’s voltage and replace it if necessary.
10. Close the trunk of the vehicle and secure it.
Materials Needed
* New CR2025 battery
* Small screwdriver or flathead key
Steps to Change the Battery
1.
Locate the Emergency Key
Pull out the emergency key from the top of the key fob.
2.
Remove the Key Fob Cover
Insert the emergency key into the slot on the back of the key fob and gently pry open the cover.
3.
Find the Battery Compartment
Locate the battery compartment inside the key fob.
4.
Remove the Old Battery
Use the screwdriver or flathead key to gently pry out the old battery.
5.
Insert the New Battery
Align the positive side (+) of the new battery with the positive terminal (+). Press it firmly into place.
6.
Replace the Key Fob Cover
Align the key fob cover and press it down until it snaps into place.
7.
Test the Key Fob
Press the buttons on the key fob to ensure they are working properly.
Alternative Battery Options
The CR2025 battery is a commonly used option, but other battery types may also be compatible with your Mercedes-Benz key fob. Here is a table comparing some alternative battery options:
| Battery Type | Voltage | Diameter | Height |
|---|---|---|---|
| CR2025 | 3V | 20mm | 2.5mm |
| CR2032 | 3V | 20mm | 3.2mm |
| CR2430 | 3V | 24mm | 3mm |
Consider the battery dimensions and voltage when choosing an alternative battery option. Thicker batteries may not fit properly, and lower voltage batteries may not provide sufficient power.
How to Change a Mercedes-Benz Key Battery
Replacing the battery in a Mercedes-Benz key is a straightforward process that can be completed in a few minutes. Here are the steps on how to do it:
- Locate the key release button on the back of the key and press it.
- Pull the emergency key out of the housing.
- Use a small flathead screwdriver to pry open the key housing.
- Remove the old battery and replace it with a new one of the same type.
- Snap the key housing back together.
- Insert the emergency key back into the housing.
People Also Ask
How often should I change the battery in my Mercedes-Benz key?
The battery in a Mercedes-Benz key typically lasts for around 2-3 years. However, this can vary depending on how often you use the key and the conditions it is exposed to.
What type of battery does my Mercedes-Benz key use?
Most Mercedes-Benz keys use a CR2032 battery. However, some older models may use a different type of battery. You can check your owner’s manual to find out what type of battery your key uses.
Can I change the battery in my Mercedes-Benz key myself?
Yes, you can change the battery in your Mercedes-Benz key yourself. However, if you are not comfortable doing so, you can always take it to a dealership or locksmith to have it done for you.
