Is your 2011 BMW 328i key fob acting up, especially when the weather gets cold? Many BMW owners experience issues with their key fobs in colder temperatures, leading to problems with locking, unlocking, and even recognizing personalized car settings. If you’re facing this, the culprit is likely a low battery in your key fob. Fortunately, replacing the battery in your BMW 328i key fob is a straightforward DIY task that can save you a trip to the dealership and some money. This guide will walk you through each step to replace your 2011 BMW 328i key fob battery effectively.
Before you start, it’s important to understand that BMW key fobs are sealed and require careful opening. While it might seem daunting, with the right tools and a bit of patience, you can easily complete this replacement at home. This guide is designed to help you through the process smoothly, ensuring you get your key fob working like new again.
What You’ll Need for Your BMW Key Fob Battery Replacement
To replace your 2011 BMW 328i key fob battery, you’ll need to gather a few essential items. Having everything ready before you begin will make the process quicker and easier. Here’s what you should have on hand:
-
Replacement Battery: You’ll need a VL2020 lithium-ion rechargeable battery. This is the specific type of battery used in many BMW key fobs, including those for the 2011 328i. You can find these batteries online from retailers like eBay or Amazon. Make sure to note the orientation of the terminals on your old battery before ordering to ensure the new one is a match.
-
Precision Knife or X-Acto Knife: A sharp knife is necessary to carefully open the glued key fob casing. Take your time and be cautious to avoid damaging the internal components.
-
Non-metallic Pry Tool: A credit card or a plastic pry tool will be useful for gently applying pressure to the battery during desoldering. Avoid using metal tools as they can scratch or damage the circuit board.
-
Soldering Iron and Solder: Basic soldering tools are required to remove the old battery and install the new one. If you’re new to soldering, there are many online tutorials available to help you get comfortable with the process.
-
Safety Glasses: Protect your eyes from solder fumes and any debris that might come loose during the process.
Once you have all these items ready, you can proceed with the battery replacement.
Step-by-Step Guide to Replacing Your 2011 BMW 328i Key Fob Battery
Follow these steps carefully to replace your 2011 BMW 328i key fob battery.
Step 1: Purchase the Correct VL2020 Battery
Before you begin taking apart your key fob, ensure you have the correct replacement battery. For the 2011 BMW 328i key fob, you’ll need a VL2020 lithium-ion rechargeable battery. You can find these online by searching for “VL2020 battery” along with “BMW key fob”. Reputable online marketplaces like eBay and Amazon are good places to purchase these batteries.
Make sure to check the battery terminal orientation when purchasing, as they are often offset. Having the correct battery is crucial for a successful replacement.
Step 2: Carefully Open the Key Fob Casing
The BMW key fob is sealed with glue, so you’ll need to carefully cut it open. Use a sharp X-Acto knife or precision knife. Gently score along the seam of the key fob casing. It’s crucial to avoid cutting too deep to prevent damage to the internal circuit board (PCB). Work slowly and patiently, going around the seam multiple times until you can gently pry the case open.
Once you’ve separated the top part, repeat the process for the bottom part of the key fob casing to fully expose the internal components. Again, proceed with caution to avoid damaging anything inside.
Step 3: Desoldering the Old VL2020 Battery
With the key fob open, you’ll see the circuit board with the battery soldered in place. To remove the old battery, you’ll need to desolder it. Start by using a non-metallic pry tool, like a credit card, to gently apply a small amount of tension to the battery. This will help create a gap when you apply heat.
Next, heat up your soldering iron and carefully apply it to the corner terminal of the battery. Once the solder melts, the tension from your pry tool should help lift the corner slightly. Desolder this corner terminal completely. It’s best to start with the corner terminal because the middle terminal has a longer lead, making it harder to access initially.
After the corner terminal is desoldered, you can easily remove the battery by desoldering the middle terminal. Be careful not to apply excessive heat for too long, as this could damage the PCB.
Step 4: Soldering in the New VL2020 Battery
Now it’s time to install the new VL2020 battery. Place the new battery into the battery holes on the PCB, ensuring the correct terminal orientation. Hold the PCB by its edges and gently push the battery down into place.
Apply heat to the middle terminal first. The heat will melt the existing solder, and the battery terminal will push through and settle into place.
Repeat the soldering process for the corner terminal to secure the new battery firmly onto the PCB. Ensure both terminals are properly soldered for a good connection.
Step 5: Test and Reassemble Your 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 functions: locking, unlocking, and starting your 2011 BMW 328i. Also, check if your personalized settings, like radio presets, are being recognized.
If everything works as expected, congratulations! You’ve successfully replaced your BMW 328i key fob battery. If it doesn’t work, double-check your soldering connections and battery orientation.
For reassembly, you have a couple of options. You can purchase a new key fob housing for a fresh look, or you can simply glue the old housing back together. If you choose to glue it, use a gel-type cyanoacrylate glue sparingly. Apply a small amount along the seam and press the two halves of the key fob together. Avoid using excessive glue, which could seep inside and damage the PCB or buttons.
Conclusion
Replacing the battery in your 2011 BMW 328i key fob is a manageable DIY project. By following these steps, you can restore your key fob’s functionality and avoid the cost of a dealership replacement. Remember to take your time, be careful when opening the fob and soldering, and always double-check your work. With a little patience, you’ll have your key fob working perfectly again, even in cold weather.
