BMW Key Battery Replacement

Car keys have gotten a lot smarter in the past decade or so. What used to be a finely cut chunk of metal looped onto a keyring is now a smart wireless device that opens up a world of connectivity and innovative features in your BMW.

The car key fob doesn’t even have to leave your pocket or purse for you to be able to open the doors, start the engine, open the tailgate, and more.

All of that is great, but it does mean that like just about every other critical device in your life nowadays, it requires battery power.

Since we’ve never had to really think about a replacement vehicle key battery before, but now it’s a thing and we’re here to fill in any gaps in your knowledge about BMW key fob battery replacement.

What Kind of Battery Does a BMW Key Fob Take?

You might not have heard of these fob battery types, but a BMW key and/or fob takes one of two batteries with CR designation or another with VL. We’ll explain more below:

If you’re using a regular BMW Smart Key, then you need to remove the back battery cover and change the battery with a CR2450 battery. This is straight-forward enough, and it’s not unlike replacing the batteries in the TV remote control.

If the key fob you have is a Comfort Access model, then you need the CR2032 battery. This battery is used in the 1, 3, 5, and 7 Series, as well as the BMW X3, X5, and X6 Series models. The CR2032 battery is also needed for the Sleek Slant Shaped Key, which is used for some 3, 5, and 7 Series and X3 models from 2011-2017.

One other fob exists, the Non-Comfort Access Key. This one is special because key fob battery replacement is unnecessary. This key has a rechargeable battery and will charge up every time you put it in the ignition.

If you don’t have one of the BMW key fobs, but instead use the more classic-style Diamond Key, then you should know that this key takes the VL2020 battery. It’s not designed for the user to replace the battery, however, so BMW recommends that Diamond Key users bring a dead key to a BMW dealership to get a replacement.

How do I replace the Battery in My BMW Key Fob?

The different BMW key fobs and batteries come with similar procedures for replacement, but some are slightly more complex. Below we’ll explain each.

CR2450 Battery:

This one goes in the Smart Key and just requires you to remove the key blade, open the back, take out the old battery, and pop in the new one. It’s a familiar and user-friendly experience.

CR2032 Battery:

For the Comfort Access BMW key fob, change the battery by first pressing the small tab to release the valet key. After that, there’s a small side indent that the valet key fits into, use it (or a flat screwdriver) to take off the back cover. Once off, you can remove the dead battery and replace it with a new key fob battery.

For the Sleek Slant Shaped Key, it’s a similar procedure but there’s a button rather than a tab for the valet key. A flat screwdriver will also help in removing the cover, after which you can also pop a new CR2032 battery in there.

VL2020 Battery:

As we mentioned, BMW does not recommend drivers to attempt replacing the Diamond Key battery. It is technically possible, but you’d have to cut into the plastic, switch out the batteries, and then solder in a new VL2020 battery. It wouldn’t be pretty, and it’s far harder than just going to the dealership to get a new key.

Can You Start a BMW with a Dead Key Fob?

While the BMW key’s technology has been greatly upgraded in recent years, there is still a mechanical method with which to start your vehicle using the key blade.

There’s typically a button on the fob to release the key blade and allow you to open the doors. Once inside, you can either insert the fob into the ignition slot or hold it against the key symbol on your steering column.

Push the start/stop button and you’re ready to go!

What a dead battery means is that you can’t take advantage of remote locking/unlocking, keyless entry, or keyless start. The good news is that BMW left some of the more analog features in place to use as a plan b or in an emergency.

How Long Does BMW Key Battery Last?

For the batteries that you have to replace yourself, you can expect a life span of up to 4 years. Ultimately, it depends on how much you use it, but you should get a good few years before a change is needed.

If you’re using the rechargeable Non-Comfort Access Key, then with continual recharging the key fob can last up to 10 years before you’ll need a replacement.

In the absence of any warning, you should look out for signs that the battery might be dying such as weakening signal strength. Did you have to press the unlock button two or three times before it finally opened? It might be time to change BMW batteries.

How Much Does It Cost to Replace a BMW Key Fob?

It will depend on the exact model and type of BMW key fob that you are replacing, but you can expect to pay anywhere from $300 to $410.

If you just need a replacement for the internal metal blade component, then that could cost as little as $45.

BMW dealerships talking to Consumer Reports have confirmed in the past that it can be as high as $500 for certain models, especially if you’re looking to replace the new BMW Display Key. This BMW key fob also has a rechargeable battery.

The more complex the key fob, the more it will cost. The simpler Diamond Key for example will only cost around $180 on average, depending on where you are applying for it.

To get a smart key battery replacement, the vehicle doesn’t need to be with you at the dealership, but you’ll need your VIN, registration, and license. You can also call ahead to get a quote so you can plan the budget before you go down there.