Is your Mini Cooper flashing a low key battery warning? You’re likely wondering about the Mini Key Fob Replacement Cost. Dealerships often recommend a full key fob replacement, which can be surprisingly expensive. However, for many Mini owners, especially those with models lacking the comfort access package, a DIY battery replacement is a viable and much cheaper alternative. This guide will walk you through the process of replacing the battery in your sealed Mini key fob, saving you money and hassle.
Many Mini Coopers come with key fobs that, according to BMW/Mini, have non-replaceable batteries. This is particularly true for models without the comfort package, where the key fob is sealed, and designed to be charged inductively in the car. When you see a warning light on your dashboard indicating a low key fob battery, the immediate thought might be a costly trip to the dealership and a hefty bill for a new key fob.
While dealerships will happily sell you a brand new key fob, understanding the anatomy of your key fob reveals a simpler solution: replacing the battery yourself. The “sealed” key fob isn’t truly impenetrable; with a bit of careful work, you can access and replace the battery inside. This not only saves you significantly on the mini key fob replacement cost but also offers a satisfying DIY project for car enthusiasts.
For those with the comfort access package, the situation is simpler. These key fobs are designed with user-replaceable batteries, making the process straightforward, as shown in your owner’s manual.
However, if you, like many Mini owners, have the standard sealed key fob, don’t despair. Replacing the battery is still achievable at home. Before we delve into the DIY process, let’s consider the typical mini key fob replacement cost at a dealership. Depending on your location and dealership, a new Mini key fob, including programming, can range from $300 to $700 or even more. This high cost makes the DIY battery replacement option incredibly appealing.
Let’s get started with the battery replacement. Here’s what your standard Mini key fob looks like:
Even with a dead battery, your Mini key fob has a backup plan. A physical key is hidden inside, allowing you to manually unlock and start your car. This is a useful feature while you’re tackling the battery replacement.
Step-by-Step DIY Mini Key Fob Battery Replacement
1. Removing the Chrome Ring:
The first step is to carefully remove the chrome ring surrounding the key fob. Many online tutorials show this being done effortlessly. However, be warned: this ring is delicate. Even with utmost care, there’s a risk of breakage.
Use a thin plastic pry tool or a very small flathead screwdriver to gently work around the ring, attempting to unclip it. Apply steady, even pressure, but be prepared for it to potentially crack. The functionality of the key fob won’t be affected if the ring is damaged, it’s purely cosmetic.
2. Opening the Sealed Key Fob:
This is the most challenging part. The key fob is glued together and needs to be carefully separated. A sharp knife is essential for this step. Safety is paramount, so take precautions to avoid injury.
A vise and some rags can help secure the key fob while you carefully cut along the seam where the two halves join. Work slowly and patiently, cutting gradually around the entire circumference of the key fob. The goal is to cut through the glue without damaging the internal components.
Once you’ve cut deep enough around the entire seam, you should be able to gently pry the two halves of the key fob apart.
3. Accessing the Circuit Board and Battery:
With the key fob open, the internal circuit board should be easily accessible. In most cases, it will simply lift out.
The battery is soldered onto this circuit board. You’ll need basic soldering skills and equipment for the next step.
4. Battery Removal and Replacement:
Carefully desolder the old battery from the circuit board. Note the orientation of the battery (positive and negative terminals) before removal.
The battery type is typically a Panasonic VL2020-1HFN rechargeable battery, specifically designed for BMW/Mini key fobs.
When ordering a replacement battery online, ensure you get the correct type and, importantly, that the connector clips are in the same orientation as your original battery. Variations in clip angles (90, 120, or 180 degrees) exist. In this case, the clips are 180 degrees apart.
5. Soldering the New Battery:
Solder the new battery onto the circuit board. Ensure correct polarity and secure soldering joints.
While you have the circuit board exposed, you can observe the micro-switches responsible for button presses. These can sometimes wear out and are also replaceable if needed. Cleaning them with electronic contact cleaner can sometimes improve responsiveness.
The coil on the back of the circuit board is part of the inductive charging system, allowing the key fob to recharge wirelessly in the car’s dashboard.
Important Note: While working with electronic components, electrostatic discharge (ESD) is a potential risk. Proper ESD precautions, like using a grounded workstation and wrist strap, are recommended, especially in professional settings. However, for a simple battery replacement, taking reasonable care to avoid static buildup is usually sufficient.
Compare the old and new batteries to ensure they are identical and will fit correctly.
Double-check the polarity (+ and -) with a multimeter before soldering. Also, note the size and orientation of the connector clips to avoid soldering the new battery incorrectly.
Even experienced DIYers can make mistakes. In this case, the battery was initially soldered on the wrong side of the circuit board!
If this happens, carefully desolder and resolder the battery on the correct side. Ensure the battery sits at the correct height for proper reassembly.
6. Reassembly:
Carefully reassemble the key fob.
Pay attention to the mechanical key locking mechanism. Ensure it’s correctly positioned for smooth operation.
Test the mechanical key and button functions before gluing the halves back together. Once satisfied, use plastic glue to seal the key fob. Clamp the two halves together for 24 hours to allow the glue to dry and harden completely.
Refitting the chrome ring can be tricky, especially if it was damaged during removal. Use a Dremel or hand files to carefully reshape the key fob body if needed to ensure a snug fit for the chrome ring.
7. Final Testing:
Once reassembled, test the key fob functions. The low battery warning should be gone, and your key fob should work perfectly.
Mini Key Fob Replacement Cost Breakdown
- Dealership Replacement: $300 – $700+ (includes key fob, programming, labor)
- DIY Battery Replacement:
- Battery (Panasonic VL2020-1HFN): $10 – $20
- Time: 1-2 hours
- Tools (if you don’t already own them): Knife, soldering iron, solder, plastic glue, clamps (under $50 if purchased new)
As you can see, the DIY battery replacement is significantly cheaper than a full key fob replacement. The main cost is your time and a small investment in tools if needed. The satisfaction of successfully completing this DIY project and saving hundreds of dollars is an added bonus.
Conclusion
Don’t let the “sealed” key fob and dealership quotes for a full replacement deter you. Replacing the battery in your Mini key fob yourself is a practical and cost-effective solution. By following these steps and taking your time, you can avoid the hefty mini key fob replacement cost and keep your Mini key fob functioning perfectly for years to come.
