sosh

Just about one year to the day I took delivery of my 2010 E class I began getting the message "change key battery". Went to dealer parts dept purchased 2 batteries and the parts guy gave me a lesson of installation. Not a big deal. What puzzles me is that the manual shows 2 batteries if I am not mistaken for keyless go cars. Both of my keys had one battery each. Even though I was getting the message on one key I was a bit proactive and renewed the battery in both. Anyone else have to change these in a year??

petee1997

My 2010 batteries were changed a couple weeks ago after message in dash. It lasted 16 months.

sosh

16 months is better than 12. What else is interesting is that in my 2010 ML550 with keyless go the remotes have 2 batteries and not 1 like the E. Perhaps thats why my ML has not yet called for batteries and its 4 months older than the E.

AJRDU

My first battery lasted just 4 months so i changed it. The second battery lasted a year before getting that message in the MFD again.

vinrun

Do not keep your keys in a cold place.

reckrab

My car is about 1 year old and one battery is dead and the other is on it's way out (p2 with keyless go). I was just going to ask here if this is normal but now I guess I don't have to.

AJRDU

They are always in my pocket or with me. The never even stay in the garage so room temperature is as cold as my keys ever get.

aeggroup

You guys just read my mind. I just wanted to ask the same question about battery message. I see this message everytime I start the car for about 2 months already. I've got the car from November 2010, so it's about 13 months. Gotta go to the dealership to change them....thanks for info.

milist

My first battery lasted 2 months which was according to my dealer because I left the key in the vehicle (in a locked garage). Now I remove it from the vehicle and am hoping for more longevity. BTW, take the valet key out, turn it 180 degrees and push it back in. One side of the keyfob pops off exposing the battery-no tools and you're good to go in under a minute.

steelgrey

The batteries are a very common type. I found Duracell model at the local drugstore. Very easy to replace, there is no need to go to the dealer.

Racing Dad

mine just went out too. been exactly 12 months.

funny though, it still tell sme now to replace it, evne though i just did it last month.

Although reading this, the thought did occur to me, sometimes both keys happen to be in the car. my wife has 1 in her purse so it'll open the doors for her on passenger side when she's with me.

I think the alert is for her key!!

mg-E550

Same issue. Dealer was having trouble installing my remote start and turned out one issue was low battery in the key. This was after about 12 mos of ownership