I too just bought a 2015 GLK (mine is a 250). One of my two key fobs had the low-battery display so I took it to the dealer to change the battery. The parts guy told me that the batteries have very short life and that is why they keep them stocked at all times. He said the old fobs used 2 batteries whereas now they only take 1, so they have far less life in them.

 

Sorry - MB Service Advisers see so many dead key FOB batteries nowadays - they invent their own stories

Please understand the "issue" has to do with the MB FOB battery - and NOT a poblem with the FOB or your Mercedes - battery size CR2025 - which MB buys from Panasonic.

Mercedes has bought key FOB batteries from Panasonic for over 15 yrs - but 5 yrs ago Panasonic moved that factory from Japan to Indonesia - and since that move frankly the MB/Panasonic battery has gone way downhill.

So you know - even the best brand CR2025 battery like this - massive China "knock off" where $.02 batteries are sold as top brands.

Take heart thought - the BEST CR2025 battery is genuine Maxell - made in Japan - ONLY in holographic package - and 5pcs are under $3 on Amazon - see link below:

Amazon.com: CR2032 Maxell LITHIUM 5 BATTERIES: Health & Personal Care@@AMEPARAM@@http://ecx.images-amazon.com/images/I/517VB4FNhJL.@@AMEPARAM@@517VB4FNhJL

 

I replace mine once a year with a Duracell. I use my '11 GLK a lot, and I have never seen this message. The only thing I've noticed when my battery is dying is the range is diminished. When my doors won't unlock and I'm ten feet away, it's time to swap.

 

My FOB battery life was about a year. Happened to be at the dealer for a courtesy wash and the service manager provided a few spare batteries free of charge.

 

We had the SLK in for a checkup and there was a charge of $18.53 CDN for 2 CR2025 VARTA Li-Mn fob batteries!!! Next time we will give specific instructions:
Do not replace or charge us for fob batteries!!!

 

Free any time go into dealership...usually ask for 2nd key so they can do that one also

 

I own as a second owner a 2011 GLK350 with less than 50,000 miles. Drive only about 5,000 ml/per year. Got the car on 12-2017.
The key fobs both has the Panasonic CR 2025 and until today they are still doing fine. I understand you should not save the fobs close to the car, because they then talk to each other. My car is outside on the drive way and both the key fobs are in my home office in one of the drawers of my desk. My standard location for keys. This methode might save the life of the batteries?

 

I am the first owner of a 2014 GLK250. I had the message only when I bought batteries somewhere else than the dealer. Since I go to the dealer I only change them at the average of 1 year.

Also, during winter time if I wear my winter coat with metal reflection inside, time to time my key won't work unless I put it out from my pocket and push the unlock button. After it worked normally.

 

I had the same short battery life problem. I mentioned it at a service appointment, and the receptionist asked where I kept my keys. They were on a rack right next to my door to the garage, 10' from the car. She suggested moving the key storage farther away from the car. I moved the rack 10' further inside the house and away from the car, and like magic, no more short battery life on the FOB.

 

I have my key fobs both with the same batteries, 2025 Panasonic, for 2 years. I can still start my 2011 GLK350 (just 50,000ml) and still no problems. As I mentioned before, I keep the fobs in a drawer of my desk in my home. The fobs are not able to talk to the car, who sits on my driveway.

 

Bringing up this old thread as I too am all of a sudden having this issue where I'm constantly getting Low Battery Life for the fobs. I measured the voltage before I put them and they were at 3.2 volts.. then a month later I started oddly getting the Low Battery Life message, I rechecked the voltages in the fobs and now they are at 2.9. Not sure why 2.9 volts is not enough but I'm going to give it a try where a previous member suggested moving the stored location 10+ feet away from the car and see what happens.

Just a side question.. if the fob battery dies when we are out and about.. does that mean we can't start the engine and drive home? Kinda sounds like its intended purpose.

 

Please use genuine Panasonic CR2025 - like a 5 pack is under $3 on Amazon Prime (red/black packaging)


Yes - if key battery is dead - remove Keyless Go Button - and Keyfob inserted into ignition will start the car.

If you hasve Keyless Go and leave on a trip for 2-3 weeks - pull the Leyless Go Button to "turn off the ears" listening for the Key Fob

 

Thank you! That is very helpful.. here is an odd thing.. when trying to simulate a dead key fob battery, I press the lock touch door handle and/or key fob button, remove the fob battery, then with the metal key I insert and unlock the door. The glk horn/lights start flashing. I don't know if this is an MB alarm or aftermarket because we got the glk used. How would this be turned off if the key fob is dead?

 

I do not know where you put your fob, when you are at home? Mine are in a drawer of a room facing the driveway. And my car, a 2011 GLK350, is on the driveway. Maybe it helps also that my windows are double pane glass. But both the Panasonic 2025 batteries in both the fobs are 2 years and 5 month old and still going strong. Somebody told me the livespan should be about 3 years. I will find out.

 

My car is garaged. I leave my fob in the ashtray. Car built 3/12, is a 2013 GLK250. Both fobs still going strong, no battery problems yet.

 

Is the battery also a 2025 Panasonic? Somewhere on the internet I was told that the life span of those batteries is 3 years. But yours prove it can be longer. This coming December I have the batteries for 3 years. We will see.

 

If you replace new battery that nearly 3,30volts its ok. But i established that every pressing the button, battery lost 0.01 volt... When the battery decrease to nearly 3,05 volts;

the massege appears in the car,
the red light on the key stops flashing
you can still open/close the doors or use the start button,
-BUT you can NOT close or open the windows using the key.(ex: press and hold the lock key to close all windows but you cant).

So we have to replace a new one in a quick period but its unacceptable because volt is still 3 and it should be 3...
I heard that this is a software fault and service has got a software to fix that situation. If someone has any experience about this software or something, please inform...