The G Man

My fob battery is only 9 months old and I got a replace fob battery message when I try to start the car yesterday. Almost all my other car's fob battery will last more than 1 year, some as long as 2 years. How often do you guys replace your fob battery?

JSch

Mine also lasts about 9 months. Wife's Nissan remote's battery has never been replaced - 6 years old and the range is still the same.

I keep spare batteries in the house and in the car. Since I only use one key fob, I should probably check the other one's battery..

Edit: I have Keyless Go

Ferris_E550

When I got my CPO three years ago the dealer replaced the fob battery, it is still working just fine.

CarolinaBluetec

20 months since last battery change.

The G Man

Do you guys have keyless go?

KEY08

I get about 1 year and I have Keyless Go

sleeperZ96BT

6-12 months with keyless go has been my norm. I think where we park and where the keys are causes it (it's somewhat close to the house).

thenew3

With keyless go E350, 3-6 months on average with the CR2025, with a slightly thicker CR2032 it lasts about a year.

Without keyless go C300, battery at 5+ years and still working fine

dbldpr

The first time I had oil change the dealer replaced the battery on remotes. They lasted about 2 weeks Went back and told them to use new batteries this time. Knock on wood I now go in once a year for oil change and I have them replace the batteries. No problems since I told them to use new batteries.

SEC1939

I read somewhere there is a TSB on the "replace key battery" warning. A software issue.
My 05 W211 never had battery replaced. They should last a few years I'd think.

dbldpr

My dealer says it should be replaced once a year, I can live with that. The wifes cadillac has the original battery in remote and it is 16 years old. But then again that is an american car. Just the engines and transmission go out and you have to replace them.

Ejbrock

I have keyless go on two cars. The batteries last about one year.

Ferris_E550

Yes I have Keyless Go

CarolinaBluetec

Yes, I have Keyless go.

The G Man

My old BMW had keyless start as well and I park and leave my keys at the same spot in my house, the BMW fob battery lasted over 2 years before it needed replacement.

YYZ-E55

Around one year if you have KEYLESS-GO.

The G Man

Have you tried using a CR2032 on the fob?

El Cid

Replaced it in fob I ordinarily use at four years because cheap to do. Ironically, the fob I almost never use has 7 year old battery that still works fine. Do not have keyless go.
My Nissan Rogue SUV has "keyless go" and battery only lasted 18 months.

@dman

I'm not sure how long mine lasted, since I picked up a 2012 CPO nearly a year ago. One fob runs strong, the other's battery died on the morning commute a few months ago. There wasn't much notice, and I now keep a spare battery in the center console just in case.
-Adam

Ejbrock

EJbrock
+1 on keeping extra fob batteries in the car.

thefisch

Had my W212 for 2 years and already done 3 replacements (although one was by dealer when there was no warning).

I had a Toyota with keyless (smart key) for 8 years and never needed to replace battery.

MB is just better at everything.

ljoeurban

I was getting 3-6 months on key fob batteries with KEYLESS-GO. Dealer said keep key fobs away from each other. If kept close to each other they talk to each other and run down.

(Forgot when this was.)

Abrown3mtg

Replace them more often.... I learned the hard way when I left my key in the car and it locked but would not open.... had to call roadside. Not a fond memory. Resulted in a "how to break into my own car" thread here last summer....

thenew3

Yes, I've used several different CR2032's and they more than double the life of the CR2025.

They are a little snug and do require some work to take out, but other than that they work fine.

The G Man

Thanks, good to know, I will order some 2032. On paper, the CR2032 has 47% more capacity than the CR2025, 163 mAh vs 240 mAh.