BMW Key Battery Replacement

How to Change Battery BMW Key Fob Remote Replace Dead Battery
Published by YOUCANIC Automotive Experts 
Last Updated Dec 19, 2018 

Learn how to change the key battery on any BMW keyless remote. This tutorial covers all BMW key fobs including, comfort access key, smart BMW fob, and the rechargeable BMW key fobs. 

BMW Smart Key Battery Replacement


This BMW key uses CR2450 battery type. This is a larger battery compared to a 2032 battery. 

You will need to remove the metal blade key from the fob. The metal key can be used as a pry tool to open the key fob.

  1. Turn the BMW remote over. Look at the back of your BMW key. The BMW key battery is located under the back cover.  
  2. Remove the battery cover. 
  3. Remove the old battery. Simply lift the battery out-of-place to remove it.
  4. Install the new BMW key battery. Place the new BMW key battery in the place of the old battery. Do not force the battery in place. Only apply gentle pressure to the battery.
  5. Close the remote. Snap the cover back on the remote. 

BMW Key Fob Battery

This key is used in many BMW models including 1, 3, 5, 7, X3, X5, X6 Series


This BMW key uses CR2032 battery. If your key looks like this but the case won't open you may have the non-comfort access version which has a built-in rechargeable battery. 

  1. Remove the valet key from the BMW key fob. This is the metal key blade that can be used in case of emergency to open your car door or trunk. To remove the valet key, you will need to press the small tab in the keyfob then pull the valet key. 
  2. After you remove the valet key you will notice a small access port on the keyfob. Use the valet key or the flat screwdriver to remove the key battery cover. 
  3. Once you remove the battery cover, you will see the battery. Remove the dead battery and install the new one. Press the battery cover on the key with your fingers. Reinsert the valet key. 

bmw key battery can't open shell non comfort access key

BMW key that has the side indent has a rechargeable battery. It wasn't designed to be serviced that's why you can't easily open the case. The battery gets charged when it is inserted in the ignition. If you are only taking short trips, you are not allowing enough time for the key to charge.

Take at least a two hour or longer trip to recharge this BMW key. If the battery has completely died, you can open the case but it will require cutting the plastic part of the key. You can then replace the built-in battery with a new rechargeable CR2032 battery.  The other option is to purchase a new key from your dealer which typically ranges between $180-$290.

Diamond  BMW Key Battery Replacement

bmw key battery replacement

This BMW key uses VL2020 3 volt battery. 

What you'll need:

• Sharp knife
• Soldering Iron
• Glue 
• Replacement Key Battery

DIY Instructions BMW Battery Replacement

  1. Start cutting the key shell. It is easier to start at the back of the key. Very carefully cut around the perimeter of the key. Be extremely careful and avoid cutting yourself. Be careful that the knife doesn't slide. Do not cut to deep into the case or you risk damaging the circuit board.  
  2. Once the key fob is exposed you will notice the battery soldered to the circuit board. Use a soldering iron to remove the battery. You could also use pliers or razor blade to cut the terminals that are soldered to the battery. This is not recommended.  
  3. Solder the new battery in place. Always pay close attention to the orientation of the old battery. Verify that the positive and negative are oriented the correct way.
  4. Carefully put the key back together.  Use your favorite glue to glue and seal the key case.  
  5. Follow the re-initiate instructions below to program your BMW remote.   
  6. Congratulations! You're done.  

Frequently Asked Questions

Do I need to program the key fob remote after I change the battery? 

  • No. Most BMW key fobs will work after you replace the battery. No programming needed. The only exception is the rechargeable key and the instructions on how to program that key is included below. 


Follow these instructions to re-initiate the key to your BMW. You will need to follow these steps quickly. If you fail to program the key the first time, try again this time complete the steps faster. 

  1. Insert the key into the ignition. Turn it to position II. All the dash lights should turn on, but don't' start the car. Only keep the key in position II  for one second then remove the key.
  2. Next, press and hold the UNLOCK button. While you hold down the unlock button press the LOCK button 3 times. All the locks cycle through locking and unlocking on their own. 
  3. Then turn key to position II then off again to finalize the programming. 

What about rechargeable BMW keys? 

  • Some BMW keys have rechargeable batteries that get charged via induction when inserted into the ignition. The rechargeable battery inside the BMW key will eventually stop holding a charge. Common problem if the key is over ten years old.

The BMW dealers will not service these keys. For example the diamond BMW key. That doesn't mean that you can't service these keys yourself. We will show you how to replace the battery even in the diamond BMW key fob. Don't rush and buy a new key. New BMW keys cost between $350 - $600 USD. You can save hundreds by replacing the BMW key fob battery yourself. 

What battery do I need for my BMW Key?

  • BMW uses several battery types in their keyless remote. The most common battery types used in BMW keys are CR2032, 2025, 2020 and 2450. 

My BMW key battery dead, what shoudl I do? 

Has the BMW key fob stopped locking and unlocking the doors? Maybe the key range is not very good. Or you may have a warning symbol on your dashboard. You will get a warning on your instrument cluster saying remote control battery discharged. To fix these problems you will need to replace the dead key fob battery. Once the BMW key fob battery dies, the keyless entry remote will stop working. While you won't be able to lock/unlock the key with the remote. At least you will still be able to start your BMW. Make sure to use a new lithium battery as those last much longer. Follow this how to replace BMW key fob battery guide.

Yes. Follow the instructions in this page to learn how to change the key battery on any BMW keyless remote.

The most common battery sizes for BMW key fobs are 2020 and 2025.

Follow this tutorial which shows you how to change the battery on any BMW remote.

Yes. You will need to cut the BMW key open. Then use a soldering iron to remove the old battery.

2000-2010 E46 2000–2004E65/66/67/68 2002–2008 E85/E86 Z4 roadster/coupe 2002–2008 Z4 E83 X3 crossover SUV 2003–2010 X3 E60 5 series 2003–2010 E63/E64 convertible 2003–2011 E61 5 series 2004–2011 E70 X5 SUV 2006–2013 E71 X6 2008–2014 E81/E87 1 series 2004–2011 E82/E88 1 series 2007–2011 E90/E91/E92/E93 3 series 2005–2011 E84 X1 SUV 2009–present F01/F02/F03/F04 7 series 2008-2015 E89 Z4 roadster 2009–2016 F10 5 series 2009–present F11 5 series 2009–present F07 5 series 2009–present 2010-Present F12/F13 6 series 2011–present F20/F21 1 series 2011–present F25 X3 SUV 2011–present F30/F31 3 series 2012–present F34 3 series 2013–present F32/F33 4 series 2013–present F15 X5 SUV 2013–present F16 X6 SUV 2014–present i3 compact electric 2013–present F26 X4 crossover SUV 2014–present i8 electric 2014–present G11/G12 7 series 2015–present G30 5 series 2016–present

It is possible that your BMW is damaged. It may be necessary to contact your BMW dealer and ask for advice on how to resolve your issues with a key.

Some BMW models such and e and 5 series E46 and E39 use rechargeable batteries. These batteries last longer but they may eventually die. They can be replaced but require special batteries.

This guide will be helpful to owners of  BMW 1-Series, 3-Series, 5-Series, 6-Series, 7-Series, X1, X3, X5, X6, Z4, M3, M5 and M6. Including models such as: 316i, 320i, 320xi, 328i, 335i, 335is, 228i, 235i, 428i, 435i, 420d, 528i, 535i, 640i, 650i, 640d, 650i, F01, 730d, 740i, 750i, 740Li, 750Li. Model years: 2000, 2001, 2002, 2003, 2004, 2005, 2006 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017

  • E60 530 Smart Key
  • BMW 5 E60 / E61
  • BMW 1, 3, 5, 7 series X5
  • E39 (1997 – 2003)
  • BMW E31 E32 E34 3 Button Remote Key FOB
  • M135i, E90, E91, E92, E93, 316i, 320i, 320xi, 328i, 335i, 335is, 228i, 235i, 428i, 435i, 420d, E60, F10, 528i, 535i
  • BMW M5 and M6
  • BMW E46 key battery replacement
  • DIY Replace BMW Comfort Access Key FOB Battery

You have comfort access key, if you do not have to insert the key to start the car. Your BMW is equipped with the Start/Stop button.

If you are experiencing problems with range the most likely cause is the battery in your key fob needs to be replaced.

If the BMW key does not work after you change the battery, you need to open the key fob again and check to make sure the battery isn't installed backward. Look at the + and - sign on the battery shell and make sure it matches with the symbols on the battery. The second procedure that you should try is to insert the key into the ignition and let it inserted for at least 15 seconds.

Your BMW key won't only unlock the door but will open the trunk, allow you to roll down your windows or trigger the alarm if case of an emergency.

We hope that these instructions were easy and helped you learn how to change a BMW key fob battery. If your BMW key fob is not covered here, please leave a comment with the year and model of your BMW and we will work on putting together a video on how to replace the battery on that particular BMW remote.