How to Replace the Battery in Your BMW Key Fob Battery Replacement
Is your BMW key fob not working? Chances are the battery has died and it’s time for a replacement. Replacing the small coin battery inside BMW key fobs is an easy, do-it-yourself project that will save you time and money compared to taking it to the dealership. This guide covers everything you need to know, including step-by-step instructions, troubleshooting tips, and where to buy affordable replacement batteries.
Symptoms Your BMW Key Fob Battery Replacement
There are a few clear signs that indicate it’s time to replace the depleted battery in your BMW key fob:
- The doors won’t lock or unlock when you press the key fob buttons
- The headlights don’t flash when you press the lock/unlock buttons
- Significant decrease in key fob remote range
- Warning message displayed in your BMW dashboard about the key fob battery
If you’ve noticed these issues with your key fob, try replacing the battery before paying for an expensive replacement remote.
BMW Models and Key Fob Types
This DIY battery replacement tutorial applies to modern BMW models that use a wireless remote key fob. This includes most late-model BMW vehicles from the 3 and 5 series sedans to X5 and X3 SUV models.
BMW key fobs contain a small, circular CR2032 lithium coin battery that powers the remote. Newer BMW remotes feature an integrated, non-removable key inside the fob. On older key fobs, the metal key pops out from inside the plastic casing. Fortunately, the battery replacement process is very similar regardless of your specific BMW key design.
Gather the Required Tools and New CR2032 Battery
Replacing the battery inside your BMW key fob remote only requires a couple of affordable supplies:
Supplies
- New CR2032 3-volt lithium coin cell battery
- Small flathead screwdriver or special key fob tool
- Optional: replacement casing or battery tray if worn
The CR2032 battery can be purchased affordably in multi-packs from online retailers, electronics stores, home improvement stores, and even grocery stores and pharmacies like CVS. It’s convenient to buy a couple of extra replacement batteries to have on hand for the next time the battery runs down.
Carefully Disassemble the Key Fob Casing
With the supplies gathered, it’s time to dig into the battery replacement procedure. Let’s go step-by-step:
- Examine the key fob casing closely on all sides to locate the seam or small screw that allows access to the interior. This may require closely inspecting with glasses on or using a magnifying glass.
- Wedge the flathead screwdriver carefully into the seam and gently pry apart the casing. Take care not to damage the plastic casing or scratch the circuit board inside.
- If your key fob has a small Phillips head screw instead of a seam, carefully use the screwdriver to back out the screw fully to open up the case.
- With the casing removed, tip the key fob board to gently slide out the old CR2032 battery without damaging the small copper contact pads inside.
Insert the Replacement CR2032 Coin Battery
Here are the specifics on properly installing your new replacement battery:
- Hold up the battery tray toward the light to see the (+) and (-) symbols indicating orientation. You’ll insert the new battery positive-side up.
- Slide just the upper half of the new battery under the retaining clip first, then press down fully into the battery tray, oriented correctly positive-side up.
- For snap-in casing types, align all parts before firmly pressing the casing closed evenly on all sides until it clicks and locks.
- For screw-type casings, carefully match up the parts and reinstall the small Phillips head screw until just snug. Take care not to overtighten.
Testing and Using the Key Fob After Battery Replacement
Before locking everything back up, test that your BMW key fob is working again:
- Press any button like lock or unlock and verify the headlights flash or horn chirps
- Test remote range by walking up to 30 feet away and pressing buttons
- If the fob fails to work, try gently cleaning the battery contacts
In some cases, you may need to re-synchronize or reprogram the key fob with your BMW by following BMW’s instructions in your owner’s manual.
If attempting a battery replacement doesn’t restore functionality, it’s recommended to visit your BMW dealership to investigate other underlying issues.
Tips to Extend Your Replacement Battery Life
To maximize the battery lifespan after replacing it yourself, avoid draining the battery prematurely by:
- Avoid pressing the remote buttons excessively or when out of the key fob range
- Store your car key fob at least 6 feet from other electronic devices
- Set aside backup keys as reminders to use the remote sparingly
- Consider turning off the one-touch comfort open/close feature if equipped
Also check that doors fully latch closed rather than staying slightly ajar over longer periods. An interior dome light left on can also result in car battery drain that also depletes the key fob battery quicker.
Where to Buy Affordable CR2032 Replacement Batteries
You’ll get the best battery prices by purchasing CR2032 lithium coin cell batteries in multipacks from discount online retailers like Amazon rather than buying from local auto parts stores or BMW dealerships. However, in a pinch generic CR2032 batteries can also be found at most corner drug stores, electronics stores, or home improvement centers. Expect to pay between $1-3 for single CR2032 cells locally, or $5-10 for packs of 10 batteries from online battery retailers.
Buying the batteries locally on an as-needed basis can minimize having to replace expired spares after the recommended 5-year shelf life.
Conclusion
I hope this DIY guide to replacing BMW key fob batteries offered practical advice both specific to your BMW key as well as general best practices. Replacing the battery yourself avoids paying for an expensive new remote fob or dealer labor charges. Just be sure to always handle the delicate electronics carefully when taking apart the key casing and disposing of the depleted battery properly. Let me know in the comments if you have any other tips for safely swapping out BMW key fob batteries!
Frequently Asked Questions
What kind of battery does a BMW key fob use? Most modern BMW key fob remotes use a standard disc-shaped CR2032 lithium coin cell battery. This thin 3-volt cell battery can be purchased very affordably from online retailers and many local stores.
How often do you need to replace the BMW key fob battery? On average, plan to replace your BMW smart key battery about once every 1-2 years with normal use. Keeping fresh batteries on hand makes for easy DIY swaps when the low battery warning appears.
Can I replace the battery myself? Yes! Following the step-by-step instructions in this guide makes safely replacing the small battery in your BMW remote control key fob an easy 5-minute job using just a screwdriver and the correct CR2032 replacement battery.