Is your 2010 BMW key fob acting up, especially when the temperature drops? You’re not alone. Many BMW owners experience issues with their key fobs in cold weather, often due to a dying battery. Symptoms can include the key fob failing to lock or unlock your car remotely, and your BMW not remembering personalized settings like radio presets when starting after a cold spell. Before rushing to a dealership and spending a significant amount on a replacement, you can easily replace the battery yourself. This guide will walk you through the process of a 2010 Bmw Key Fob Battery Replacement.
Before we begin, it’s crucial to understand that these BMW key fobs are sealed and not designed for battery replacement. However, with careful steps and the right tools, it’s a manageable DIY task. This guide is based on personal experience and is intended for informational purposes only. Always proceed with caution and at your own risk when performing DIY repairs.
What You’ll Need:
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Replacement Battery: You will need a VL2020 Lithium-Ion battery. It’s essential to get the correct battery type to ensure proper function and longevity. You can find these batteries online from retailers like eBay or Amazon. Make sure to note the terminal orientation when purchasing, as they need to match the original battery.
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Sharp X-Acto Knife or Precision Knife: This is necessary to carefully open the glued key fob casing. Patience is key here; avoid deep cuts to prevent damage to the internal circuit board (PCB).
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Non-Metallic Pry Tool: A credit card or a plastic spudger will work perfectly. Avoid using metal tools to prevent short circuits or damage to the delicate electronic components.
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Soldering Iron and Solder: You will need basic soldering skills to remove the old battery and install the new one. If you’re not comfortable soldering, consider practicing on scrap electronics first.
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Cyanoacrylate Glue (Gel Type): For re-sealing the key fob casing. Gel type is recommended as it’s less likely to run and get into unwanted areas.
Step-by-Step 2010 BMW Key Fob Battery Replacement:
Step 1: Purchase the Correct Battery
The first crucial step is to acquire the correct replacement battery. For a 2010 BMW key fob, you’ll typically need a VL2020 rechargeable Lithium-Ion battery. These batteries are specifically designed for key fobs and similar devices. Websites like eBay and Amazon are good sources. Ensure the battery terminals are oriented correctly before purchasing.
Step 2: Carefully Open the Key Fob Casing
The BMW key fob is sealed with glue, requiring a careful approach to open it without damage. Using your sharp X-Acto knife, gently score along the seam line of the key fob. Take your time and make multiple shallow passes rather than trying to cut through in one go. Work your way around the entire perimeter of the fob. Avoid pressing too hard to prevent accidentally cutting into the PCB inside.
Step 3: Desolder the Old Battery
Once the key fob is open, you’ll see the PCB with the battery soldered in place. To remove the old battery, use your non-metallic pry tool (like a credit card) to gently apply a small amount of upward pressure to the battery. Focus on the corner terminal first, as it’s more accessible. Apply heat to the corner solder joint with your soldering iron until the solder melts, and gently lift that corner of the battery. Repeat for the other terminal. The battery should now be free.
Step 4: Solder in the New Battery
Place the new VL2020 battery into the battery holder on the PCB, ensuring the terminals align correctly with the solder pads. Hold the PCB by its edges and gently push the battery down into place. Apply heat to the solder pads on the PCB, allowing the existing solder to reflow and secure the new battery terminals. Start with the middle terminal, then move to the corner terminal. Ensure a good solder joint for a reliable connection.
Step 5: Test the Key Fob
Before permanently sealing the key fob, it’s crucial to test if the new battery is working. Dry fit the PCB back into the key fob housing and test all the key fob functions: locking, unlocking, and remote start if applicable. Also, check if your BMW now remembers your personalized settings. If everything works as expected, proceed to the final step. If not, double-check your soldering and battery orientation.
Step 6: Reassemble the Key Fob
If your key fob is functioning correctly, it’s time to reassemble it. You have a couple of options here. You can purchase a new key fob housing for a fresh look, or you can simply glue the original housing back together. If you choose to glue it, use the gel-type cyanoacrylate glue sparingly. Apply a thin bead of glue along the seam of the key fob housing and carefully press the two halves together. Hold it firmly until the glue sets. Avoid using excessive glue, which could seep inside and damage the PCB or buttons.
Conclusion:
Replacing the 2010 BMW key fob battery is a straightforward DIY project that can save you money and restore the functionality of your key fob. By following these steps carefully, you can successfully replace your BMW key fob battery and avoid the cold weather frustrations. Remember to take your time, be patient, and double-check each step for a successful outcome. Enjoy the restored convenience of your key fob!
