Experiencing issues with your 07 BMW key fob, especially when the temperature drops? It’s a common problem – cold weather can significantly impact your key fob’s battery performance. You might find your key fob struggling to lock or unlock your doors, or even worse, your BMW starting but failing to recognize your personalized settings. This often points to a weak or dead battery in your key fob.
Before you rush to a dealership and spend a significant amount on a replacement, consider this: you can easily replace the battery yourself. This guide will walk you through replacing the battery in your 07 BMW key fob, saving you time and money.
What You’ll Need:
- Replacement Battery: You’ll need a VL2020 lithium-ion battery. Ensure you purchase the correct battery type for your BMW key fob. You can find these online from retailers like eBay. Make sure to note the terminal orientation of your old battery before purchasing the new one to ensure compatibility.
- Sharp X-Acto Knife or Precision Knife: For carefully opening the key fob casing.
- Non-Metallic Pry Tool: A credit card or plastic pry tool will work to gently lift the battery.
- Soldering Iron and Solder: For desoldering the old battery and soldering in the new one.
- Safety Glasses: To protect your eyes during the repair process.
Step-by-Step Battery Replacement Guide:
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Open the Key Fob Casing: BMW key fobs are securely glued shut. Using a sharp X-Acto knife, carefully cut along the seam of the key fob to separate the top and bottom halves. Work slowly and apply gentle pressure to avoid cutting too deep and damaging the internal circuit board (PCB). Patience is key here.
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Desolder the Old Battery: Once the fob is open, you’ll see the battery on the PCB. Take your non-metallic pry tool (like a credit card) and gently apply a small amount of pressure to the battery to create some tension. Then, using your soldering iron, desolder the corner terminal of the battery. Focus on the corner terminal first as it will give you more space to maneuver when removing the other terminal.
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Solder in the New Battery: Place the new VL2020 battery into the battery holes on the PCB. Hold the PCB firmly by the edges and gently push the battery down into place. Apply heat with your soldering iron to the middle terminal first, and then the corner terminal. The heat will melt the existing solder, allowing the new battery’s terminals to slide into place. Ensure a good solder connection for reliable performance.
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Test and Reassemble: Before fully sealing the key fob, dry fit the PCB back into the housing and test the key fob functions with your BMW. Check if the locking/unlocking works and if your car recognizes your personalized settings. If everything is working correctly, you’ve successfully replaced your BMW key fob battery!
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Seal the Key Fob: You have a couple of options for reassembling the key fob. You can purchase a new replacement housing for a fresh look. Alternatively, you can carefully glue the original housing back together. If you choose to glue it, use a gel-type cyanoacrylate glue sparingly to prevent it from running and potentially gluing the PCB to the housing. Apply a small amount along the seam and press the two halves together until the glue sets.
Conclusion:
Replacing your 07 BMW key fob battery is a straightforward DIY task that can save you a trip to the dealer and unnecessary expenses. By following these steps, you can restore your key fob’s functionality and ensure it operates reliably, even in cold weather conditions. Enjoy the satisfaction of fixing it yourself and the savings in your pocket!
