Is your 2010 Mini Cooper displaying a low key battery warning? Don’t rush to the dealership just yet! Many Mini Cooper owners with the non-comfort access package find themselves facing a sealed key fob when the battery starts to die. While BMW/Mini might prefer you replace the entire key fob, costing a significant sum, it’s entirely possible to replace the 2010 Mini Cooper Key Fob Battery yourself. This guide will walk you through the process step-by-step, allowing you to save money and gain a little DIY satisfaction.
The original poster, BHPian Jeroen, encountered this exact issue with his Mini Cooper. He received a dashboard warning indicating a low key fob battery. Unlike comfort access key fobs which have easily replaceable batteries, his sealed fob required a more hands-on approach. Undeterred by the manufacturer’s sealed design, Jeroen decided to tackle the battery replacement himself. Let’s learn from his experience and get your 2010 Mini Cooper key fob working like new again.
First, let’s understand the type of key fob we’re dealing with. As Jeroen points out, Mini Coopers come with different key fobs depending on whether they have the comfort package. Comfort package key fobs have a removable battery compartment, making battery changes straightforward. However, if your 2010 Mini Cooper, like Jeroen’s, lacks this package, you’ll have a sealed key fob. This means the battery is not designed to be user-replaceable, and is charged inductively when placed in the dashboard slot.
Despite being sealed, these key fobs are not impenetrable. With a little patience and the right tools, you can access and replace the battery.
To begin this DIY adventure, you’ll need a few tools:
- A very sharp knife (utility knife or similar)
- A small flat-head screwdriver or plastic pry tool
- Soldering iron and solder
- Desoldering wick or pump (optional, but helpful)
- Replacement battery – Panasonic VL2020-1HFN rechargeable battery (ensure the clips are oriented correctly)
- Plastic glue or epoxy
- Clamps or rubber bands
- Dremel and files (potentially, for cleanup)
Now, let’s get into the step-by-step process of replacing your 2010 Mini Cooper key fob battery.
Step 1: Prying off the Chrome Ring
The first step is to remove the chrome ring surrounding the key fob. This ring is clipped on and needs to be carefully pried off. As Jeroen discovered, even with caution, this ring can be fragile. Use a small flat-head screwdriver or plastic pry tool to gently work your way around the ring, applying even pressure to avoid breaking it.
Alt text: Close-up showing the chrome ring partially removed from a Mini Cooper key fob, illustrating the first step of disassembly.
Step 2: Opening the Sealed Key Fob
This is the most challenging part of the process. The key fob is glued together and needs to be carefully cut open along its seam. Using your sharp knife, carefully score along the seam line of the key fob. Multiple passes with light pressure are better than trying to force it open in one go. Take your time and be extremely cautious to avoid cutting yourself. Jeroen used a vice and wood blocks to secure the key fob, which is a good safety measure.
Alt text: Person using a sharp knife to carefully cut along the seam of a 2010 Mini Cooper key fob, demonstrating the process of opening the sealed case.
Once you’ve cut deep enough around the entire circumference, you should be able to gently pry the two halves of the key fob apart. A plastic pry tool can be helpful here to avoid damaging the plastic casing.
Alt text: Two halves of a disassembled 2010 Mini Cooper key fob are shown separated, revealing the internal circuit board and battery.
Step 3: Accessing the Circuit Board and Battery
With the key fob open, the internal circuit board should be easily accessible. Carefully remove the circuit board from the casing. The battery will be soldered onto this board.
Alt text: Image of the circuit board extracted from the Mini Cooper key fob casing, highlighting the next stage of battery replacement.
Step 4: Desoldering the Old Battery
Now, you need to remove the old battery from the circuit board. Use your soldering iron to heat the solder joints on the battery terminals. Once the solder is molten, you can gently lift the battery off the board. A desoldering wick or pump can be useful to remove excess solder and make the process cleaner.
Alt text: Close-up view of the soldering process on the Mini Cooper key fob circuit board, focusing on the battery terminals.
Step 5: Identifying and Installing the New Battery
The battery is a Panasonic VL2020-1HFN rechargeable battery. When ordering a replacement, ensure it has the correct clip orientation. Jeroen noticed variations in clip angles, so double-check that your new battery matches the old one in terms of clip placement (180 degrees apart in this case). Pay attention to the polarity (+ and -) and orientation before soldering.
Alt text: Side-by-side comparison of a new Panasonic VL2020-1HFN battery and the old battery removed from the 2010 Mini Cooper key fob.
Solder the new battery onto the circuit board, ensuring it’s on the correct side and at the right height, as Jeroen learned through a minor mishap. Double-check the polarity again before finalizing the solder joints.
Alt text: Image showing the new VL2020-1HFN battery correctly soldered onto the Mini Cooper key fob circuit board.
Step 6: Reassembling the Key Fob
Carefully place the circuit board back into the key fob casing. Test the mechanical key mechanism to ensure it works smoothly before gluing the halves back together. Apply plastic glue or epoxy to the seam and clamp or use rubber bands to hold the two halves firmly together while the glue dries completely (ideally for 24 hours).
Alt text: Reassembling the two halves of the Mini Cooper key fob after battery replacement, preparing for gluing.
Step 7: Refitting the Chrome Ring and Final Check
Once the glue is dry, refit the chrome ring. This can be fiddly, and you might need to use a Dremel or files to clean up any imperfections from cutting the case open, as Jeroen did. Ensure the ring is securely attached.
Alt text: Completed and repaired 2010 Mini Cooper key fob with new battery, chrome ring reattached, ready for use.
Finally, test your 2010 Mini Cooper key fob. The low battery warning should be gone, and your remote functions should work perfectly.
Conclusion
Replacing the 2010 Mini Cooper key fob battery in a sealed unit is a manageable DIY task. While it requires some careful cutting and soldering, it’s a cost-effective alternative to buying a new key fob from the dealer. By following these steps and taking your time, you can successfully breathe new life into your key fob and avoid unnecessary expenses. Remember to always exercise caution when using sharp tools and soldering equipment. With a little effort, you can keep your 2010 Mini Cooper running smoothly, right down to the key in your pocket.
