Replacing a battery in a Mercedes key fob is an easy task that anyone can do. The process is simple and only takes a few minutes. With a few simple tools, you can save time and money by replacing the battery yourself.
First, you will need to gather the necessary tools. You will need a small screwdriver, a new battery, and a pair of tweezers. Once you have gathered the necessary tools, you can begin the process of replacing the battery. Start by prying open the key fob using the small screwdriver. Be careful not to damage the key fob. Once the key fob is open, you will see the battery. Use the tweezers to remove the old battery and insert the new battery. Make sure that the positive and negative terminals of the battery are facing the correct way. Once the new battery is in place, you can close the key fob and test it to make sure that it works properly
Replacing a battery in a Mercedes key fob is a simple task that anyone can do. By following these simple steps, you can save time and money by doing it yourself. With a few simple tools, you can keep your Mercedes key fob working properly for years to come.
Tools and Materials Required
A decent-sized flat-head screwdriver, such as one from a small electronics tool kit.
A flat-head screwdriver is the primary tool you need to replace the battery in your Mercedes key fob. Choose a medium-sized flat-head screwdriver, as it will fit the screws on your key fob without being too bulky or too small. Avoid using a screwdriver that is too large or too small, as it could damage the key fob or the screws.
A spare battery that is compatible with your Mercedes key fob
Before you start the replacement process, you need to make sure you have a new battery that is compatible with your Mercedes key fob. Refer to your key fob’s user manual or the battery’s packaging to determine the correct battery type. Common battery types used in Mercedes key fobs include CR2025, CR2032, and CR2430.
A small magnet or a pair of tweezers
A small magnet or a pair of tweezers can be useful for retrieving the old battery and inserting the new one. If the new battery falls out of your grasp, you can use the magnet to retrieve it from hard-to-reach areas inside the key fob.
A clean cloth or paper towel
A clean cloth or paper towel can be used to clean the battery contacts in the key fob. Over time, the battery contacts can accumulate dirt and debris, which can interfere with the key fob’s operation. Use the cloth or paper towel to gently wipe away any dirt or debris from the contacts.
Identifying the Key Fob Type
Mercedes-Benz key fobs have undergone several design changes over the years. To determine the type of key fob you have, examine its shape, size, and button layout:
Key Fob Shape
Early Mercedes-Benz key fobs were typically rectangular or square in shape. Newer models are often more compact and streamlined, with rounded edges and a more ergonomic design.
Key Fob Size
Key fob sizes vary depending on the model and year of the vehicle. Early fobs were generally larger, while newer fobs are more compact and lightweight.
Button Layout
Mercedes-Benz key fobs typically feature a combination of physical buttons and a touch-sensitive control panel. The location and arrangement of these buttons and controls can vary depending on the fob type.
For example, the “W164” key fob used in 2006-2013 Mercedes-Benz vehicles has a rectangular shape with two physical buttons on the front and a touch-sensitive control panel on the back. In contrast, the “W222” key fob used in 2014-2020 Mercedes-Benz vehicles has a more rounded shape with a single physical button on the front and an integrated touch-sensitive display.
| Key Fob Type | Shape | Size | Button Layout |
|---|---|---|---|
| W164 (2006-2013) | Rectangular | Large | Two physical buttons, touch-sensitive control panel |
| W222 (2014-2020) | Rounded | Compact | Single physical button, integrated touch-sensitive display |
Locating the Battery Compartment
Identifying the battery compartment in a Mercedes key fob can vary depending on the specific model and year of your vehicle. Here is a detailed guide to help you locate the battery compartment:
1. Examine the Key Fob for Release Buttons
Many Mercedes key fobs feature small release buttons or levers on the sides or edges of the fob. Locate these buttons and gently press them inward while pulling the fob apart. For some models, you may need to press multiple buttons at once to release the case.
2. Pry Open the Battery Compartment
Once the main case has been opened, you may need to further pry open the battery compartment. This can often be achieved by using a small screwdriver to gently pry on the edges of the compartment or by pressing a dedicated release button.
3. Remove the Battery
Once the battery compartment is accessible, you will need to carefully remove the old battery. Note the orientation of the battery and make sure to remove it in the same direction it was inserted. Use a pair of tweezers or a small screwdriver to gently lift the battery out of its compartment.
| Battery Type | Mercedes Models |
|---|---|
| CR2025 | E-, S-, C-, and G-Class (2005-2015) |
| CR2032 | E-, S-, C-, G-, and CL-Class (2016-Present) |
| CR2450 | A-, B-, and GLA-Class (2014-Present) |
Opening the Battery Compartment
Step 1: Locate the Battery Compartment
The battery compartment is typically located on the back or bottom of the key fob. Look for a small, recessed area with a release button or lever.
Step 2: Press the Release Button
Locate the release button or lever on the battery compartment. Press it to unlatch the compartment.
Step 3: Slide Open the Compartment
Once the latch is released, carefully slide open the battery compartment. Be gentle to avoid damaging the compartment or the key fob.
Step 4: Lift and Remove the Old Battery
Use a small, flat-head screwdriver or a plastic pry tool to gently lift the old battery out of the compartment. Note the orientation of the battery before removing it, as the new battery must be inserted in the same direction.
| Battery Type | Orientation |
|---|---|
| CR2025 | Positive Side Up |
| CR2032 | Positive Side Up |
Removing the Old Battery
To remove the old battery, you will need a small screwdriver or a key.
1. Locate the battery compartment
The battery compartment is usually located on the back of the key fob, but it can also be located on the side or even inside the fob. Look for a small door or panel that can be opened to reveal the battery.
2. Open the battery compartment
Use the screwdriver or key to pry open the battery compartment. Be careful not to damage the compartment or the key fob.
3. Remove the old battery
Once the battery compartment is open, you can remove the old battery. Use your fingers or a pair of tweezers to gently lift the battery out of the compartment.
4. Dispose of the old battery properly
Batteries contain hazardous materials, so it is important to dispose of them properly. Do not throw batteries in the trash. Instead, recycle them at a local battery recycling center or drop them off at a hazardous waste collection site.
5. Additional tips for removing the old battery
- Before you remove the old battery, check if you have a replacement battery on hand. This will save you time and frustration.
- If the battery compartment is difficult to open, you can try using a small amount of WD-40 or other lubricant to loosen the hinges.
- Be careful not to drop the old battery. If the battery comes into contact with your skin, wash the area immediately with soap and water.
- If you are having trouble removing the old battery, you can take your key fob to a locksmith or an automotive electrician for assistance.
| Step | Action |
|---|---|
| 1 | Locate the battery compartment |
| 2 | Open the battery compartment |
| 3 | Remove the old battery |
| 4 | Dispose of the old battery properly |
Inserting the New Battery
Step 1: Remove the Old Battery
Gently pry open the key fob using a small flathead screwdriver or plastic tool. Locate the battery compartment and remove the old battery, taking note of its orientation.
Step 2: Insert the New Battery
Choose a new battery of the same type and size as the old one. Refer to your key fob manual for specific battery specifications.
Step 3: Correct Orientation
Ensure the new battery is inserted with the positive (+) terminal facing up, aligning with the corresponding contact point in the compartment.
Step 4: Securely Place the Battery
Gently press down on the battery to ensure it is securely seated in the compartment. Avoid overtightening, as this can damage the battery or key fob.
Step 5: Test the Key Fob
Reinsert the key into the key fob and test its functionality. If the buttons are unresponsive, double-check the battery orientation and connections.
Step 6: Additional Tips
To prolong the life of your key fob battery, consider the following tips:
| Tips | Description |
|---|---|
| Avoid excessive use | Minimize unnecessary button presses to conserve battery power. |
| Store key fobs in a cool, dry place | Extreme temperatures can degrade battery performance. |
| Replace batteries regularly | Even unused key fobs may gradually drain the battery over time. |
Closing the Battery Compartment
To close the battery compartment, follow these steps:
- Align the positive terminal (+) of the battery with the positive terminal inside the compartment.
- Gently push down on the battery to secure it in place.
- Slide the battery compartment back into the key fob, ensuring it fits snugly.
- Press the small latch on the side of the key fob to lock the compartment.
- Check if the key fob is working by pressing the buttons and observing if the corresponding lights illuminate or the car responds.
- If the key fob is not functioning correctly, repeat the steps and ensure that the battery is inserted correctly and all connections are secure.
- If the key fob still does not work after replacing the battery, consult with a professional automotive technician or Mercedes-Benz dealership for further assistance.
Testing the Key Fob
Before you proceed with replacing the battery, it’s essential to test the key fob to determine if a battery swap is indeed the solution. Here’s how to test it:
- Unlock the Car Manually: Use the physical key to unlock the car door. This confirms that there’s an issue with the key fob, not the car.
- Check the LED Light: Press any button on the key fob and observe if an LED light flashes. If it does, the battery might still have some charge, but it’s weak and needs replacement.
- Try a Different Key Fob: If you have a spare key fob, try using it to unlock the car. If the spare fob works, it confirms that the issue lies with the primary key fob’s battery.
- Check for Corrosion: Inspect the battery terminals inside the key fob for any signs of corrosion. If there’s corrosion, clean the terminals with a cotton swab and rubbing alcohol before proceeding.
- Replace the Battery: If the key fob fails all the above tests, it’s highly likely that the battery needs replacement. Proceed to the next section to learn how to replace the battery.
Troubleshooting Common Issues
The key fob isn’t working.
If the key fob isn’t working, there are several possible causes. First, check to make sure that the battery is properly installed. If the battery is installed correctly, try replacing it with a new battery. If the key fob still doesn’t work, there may be a problem with the key fob itself. In this case, you will need to take the key fob to a Mercedes-Benz dealership for service.
The key fob is working intermittently.
If the key fob is working intermittently, there are several possible causes. First, check to make sure that the battery is properly installed. If the battery is installed correctly, try replacing it with a new battery. If the key fob still works intermittently, there may be a problem with the key fob itself. In this case, you will need to take the key fob to a Mercedes-Benz dealership for service.
The key fob is not opening the doors.
If the key fob is not opening the doors, there are several possible causes. First, check to make sure that the key fob is in range of the vehicle. If the key fob is in range, try replacing the battery. If the key fob still doesn’t open the doors, there may be a problem with the key fob itself. In this case, you will need to take the key fob to a Mercedes-Benz dealership for service.
The key fob is not starting the car.
If the key fob is not starting the car, there are several possible causes. First, check to make sure that the key fob is in range of the vehicle. If the key fob is in range, try replacing the battery. If the key fob still doesn’t start the car, there may be a problem with the key fob itself. In this case, you will need to take the key fob to a Mercedes-Benz dealership for service.
The key fob is not responding to commands.
If the key fob is not responding to commands, there are several possible causes. First, check to make sure that the key fob is in range of the vehicle. If the key fob is in range, try replacing the battery. If the key fob still doesn’t respond to commands, there may be a problem with the key fob itself. In this case, you will need to take the key fob to a Mercedes-Benz dealership for service.
The key fob is stuck in the ignition.
If the key fob is stuck in the ignition, there are several possible causes. First, try jiggling the key fob. If the key fob still doesn’t come out, try turning the steering wheel back and forth. If the key fob still doesn’t come out, you may need to call a locksmith to remove it.
Mercedes Key Fob Battery Replacement Cost
| Model | Year | Battery Replacement Cost |
|---|---|---|
| Mercedes-Benz C-Class | 2015-2023 | $150-$200 |
| Mercedes-Benz E-Class | 2016-2023 | $150-$200 |
| Mercedes-Benz S-Class | 2014-2023 | $200-$250 |
Safety Precautions
Before handling the key fob battery, it’s crucial to observe the following safety precautions:
- Have the Correct Tools: Ensure you have the necessary tools, including a small screwdriver or key fob battery replacement kit.
- Avoid Static Electricity: Discharge any static electricity by touching a grounded metal object before handling the battery.
- Wear Gloves: If possible, wear rubber gloves to prevent skin contact with the battery’s terminals or chemicals.
- Work in a Safe Area: Choose a well-lit and ventilated area to avoid accidents or exposure to harmful substances.
- Read Manufacturer’s Instructions: Carefully review the manufacturer’s instructions for your specific key fob model.
- Disconnect Electrical Power: If applicable, disconnect the vehicle’s battery or remove the key fob from the ignition before starting the process.
- Handle the Battery Carefully: Avoid bending or twisting the battery, as this could damage its casing or terminals.
- Avoid Eye Contact: Handle the battery with care to prevent contact with your eyes or skin.
- Do Not Ingest the Battery: Keep the battery out of reach of children and pets, as ingestion can be dangerous.
- Dispose of Battery Responsibly: Follow proper disposal guidelines for lithium-ion batteries, which may vary depending on your location. Consult with local authorities or battery recycling centers for appropriate disposal methods.
| Safety Tip | Reason |
|---|---|
| Discharge Static Electricity | Prevents accidental discharge or damage to the battery. |
| Avoid Skin Contact | Protects against potential chemical reactions or skin irritation. |
| Work in a Safe Area | Reduces risks associated with fumes, spills, or explosions. |
| Disconnect Electrical Power | Prevents electrical shocks or short circuits during the process. |
| Handle Battery Carefully | Maintains the integrity of the battery and its terminals. |
| Proper Battery Disposal | Protects the environment and prevents potential hazards. |
How To Change A Battery In A Mercedes Key Fob
Replacing the battery in a Mercedes key fob is a quick and easy process that can be done in just a few minutes. Here are the steps on how to do it:
- Locate the small screw on the back of the key fob. Use a small screwdriver to remove the screw.
- Gently pry open the two halves of the key fob. Be careful not to damage the circuit board.
- Locate the battery. It will be a small, round battery, usually a CR2025 or CR2032.
- Use a small screwdriver or your fingers to gently pry the battery out of its holder.
- Insert the new battery into the holder, making sure that the positive (+) side of the battery is facing up.
- Snap the two halves of the key fob back together.
- Replace the screw on the back of the key fob.
Your Mercedes key fob should now be working again.
People Also Ask About How To Change A Battery In A Mercedes Key Fob
How often should I change the battery in my Mercedes key fob?
The battery in a Mercedes key fob typically lasts for about two to three years. However, the lifespan of the battery can vary depending on how often the key fob is used.
What are the signs that my Mercedes key fob battery is dying?
There are a few signs that your Mercedes key fob battery is dying, including:
- The key fob has to be held closer to the car to work.
- The key fob has to be pressed multiple times to work.
- The range of the key fob is reduced.
