Mercedes key battery replacement: the basics
Are you browsing the web to replace your Mercedes key battery? If you can’t access your vehicle, that means you need a quick response. If not, we’re sure you’ll still enjoy it.
What type of battery does a Mercedes key fob use?
Your Mercedes key probably uses a pair of CR 2025 3 volt batteries. But before purchasing a replacement, you’ll want to check your owner’s manual or remove the old batteries to be sure. You can then take them to the store with you to check.
That brings us to another question: how do you remove old batteries in the first place? Read on and we’ll let you know, as well as explain where to find a replacement and how much it will cost.
Where can you get a CR 2025 3 volt battery?
You can find CR 2025 3 volts almost anywhere they sell batteries. Wal-Mart, gas stations, supermarkets, Amazon. This is a fairly common type of battery for small electronic devices, so you can find them everywhere.
You’ll usually see them sell for around three dollars, or you can buy a pack and save some cash.
You can find Mercedes brand key fob batteries that are a little more expensive, usually around five dollars each, but you only pay more for the packaging. There is no reason to buy a 2025 Mercedes CR when a Panasonic will do just fine.
Some drivers have reported that a CR 2032 works better, improving the range of the key fob. The number refers to the physical size of the battery, 2.5mm for the 2025, 3.2mm for the 2032. The voltage is the same, so if the 2032 fits, it will work.
Mercedes Key Battery Replacement – How To
If you have a smart key
- Hold your key by the key ring.
- Pull the sliding tab and then remove the valet key.
- Move the valet key to the other side where it can be inserted into the key ring and push it down.
- Remove the back of the keychain.
- Install the new batteries, then reassemble them by following the above steps in reverse order.
If you have a Chrome key

- Pull the bottom tab out on the remote control until the key releases.
- Press the key onto the tab on the flat end of the key ring to open the cover.
- Replace the key and put everything back together.
You can always have them replace the battery in the store, but it’s a cheap fix that should only take a few minutes, so why not do it yourself?
Once you have the new batteries in place and reassembled the key fob, take it to the car and test it. If you replaced the batteries correctly but the remote does not work, the problem may not be the batteries, so you will need to troubleshoot.