replace key battery (I did and warning light still on)
 

Hey everyone.
I just installed a brand new Energizer CR2025 and my "replace key battery" still stays on on my dash. what is going on?

also would the fact that I keep my key always in my ML since I leave it parked inside my garage, would that cause the battery to drain because it is always being detected?

thanks for any input

Do you have a second key? Does that error message come with the other key as well OR just with this key?

If I were you, I wouldn't leave the key in the ignition overnight everyday like that... even if the car is secured in the house/garage.

usually dealer does it for free?

Battery in properly ?

When I had problems with my Keyless GO on my W212- I replaced all my batteries with brand new Energizers. The first thing the dealership did was replace the Brand New batteries with Panasonic. They said they sometimes have issues with other brand batteries. I don't understand since Energizer or Duracell should be premium brand batteries.

I would do as suggested as well. Panasonic batteries went on back order so we purchased interstate batteries and we had 50 sets of them not work right out of the package. It goes with anything really in the industry MB requests a certain quality to be maintained from what they are purchasing from their vendors which they might not do on their own. Same with companies like apple who outsource their components. Also if it doesn't work you can have service check it out as well since your car is still new I am guessing it maybe be under warranty.

update, my key seems to be working fine now. I guess next time I will try and find Panasonic batteries

Now that wifey and I both drive a Mercedes- I bought a bunch off of Amazon.

A bunch of Panasonics?

Yes. They were under $10 for 10.

I replace our key battery with Energizer brand batteries, and have never had a problem.

CR2032 works as well in the key. Slightly thicker but enuff room to fit in my key.

All batteries are the same rather its Panasonic or whatever...... It probably the source and age of the battery that's the problem. If you have a volt meter, it should read more than 3V.

The Energizers I bought were brand new with an expiration date of 2022. I even had the packages and the receipts.
All batteries are not created equal. Do some research online and brands you would consider "premium" brands are not always the best performers.

Panasonic - even when genuine like MB branded package - are made in Malaysia for the past 6yrs - suck.

Hard to understand - but button cell batteries are one of the largest volum knockoff business - w/China and Indonesia junk being sold as branded battery.

For CR2025 the ONLY Japanese made battery left is Maxell CR2025 - in HOLOGRAM package ONLY !

See 5-pack (less than $.60 ea) and 20-pc pack ($.35 ea) on Amazon below as examples:

I am using a Duracell battery in my key fob as we speak. I agree, the performance can vary, but when new, as long as they output 3 volt, its fun.

Do you find it lasts longer than the 2025?

Haven't had it in long enough...but range seems better