[DanG]

Got an interesting message from my BMW today. It said the key battery was critically low. Also showed a warning triangle on the dash.

I was quite surprised. I have never had to change a key battery on any of my previous BMWs and some I owned for over ten years.

I did find a YouTube video instructions. Luckily I had a 2450 battery at home. Replaced the battery and warring signs disappeared.

Anyone else had to replace their key battery?

Here is the video:

[F87source]

Originally Posted by DanG

Got an interesting message from my BMW today. It said the key battery was critically low. Also showed a warning triangle on the dash.

I was quite surprised. I have never had to change a key battery on any of my previous BMWs and some I owned for over ten years.

I did find a YouTube video instructions. Luckily I had a 2450 battery at home. Replaced the battery and warring signs disappeared.

Anyone else had to replace their key battery?

Here is the video:

Yup I had to do it twice on my key already, it's a pretty simple job but I use a dull flat head from my swiss army knife to do it instead of the key blade, because I found the key blade marrs the case a bit.

My key got so low I had to hold it against the steering column for a start.

[///M TOWN]

Yeah my spare that I never use was completely dead

I replaced both with a new battery

[nioh_lbbm2]

How do you guys use the fob? Do you use the buttons? How long has you guys had your car?

I'm going on 3+ years and still haven't needed to change my battery. Car is my daily.

Then again it's always in my pocket and I only use comfort access :

[DanG]

Originally Posted by nioh_lbbm2

How do you guys use the fob? Do you use the buttons? How long has you guys had your car?

I'm going on 3+ years and still haven't needed to change my battery. Car is my daily.

Then again it's always in my pocket and I only use comfort access :

I am like you and only use comfort access with the key in my pocket. My M2 has a November 2017 build date.

[F87source]

Originally Posted by nioh_lbbm2

How do you guys use the fob? Do you use the buttons? How long has you guys had your car?

I'm going on 3+ years and still haven't needed to change my battery. Car is my daily.

Then again it's always in my pocket and I only use comfort access :

That's the thing I don't use the key much either but I suspect since I have alot of electronics in my car and the interference does cause the key to disconnect at times (the key is not detected thing), this constant signal search likely drains the battery.

[2+3=5]

2018 daily comfort access … remote 1 batt changed after 2.5 years (open all windows with the remote thruout the summers)… switched to remote 2

[omasou]

I hung my key in the washroom with the car in the garage and it killed the battery.

[F87source]

Originally Posted by omasou

I hung my key in the washroom with the car in the garage and it killed the battery.

Probably the constant communication. I sometimes wish there was an option for traditional key start.

[Pray for Mojo]

Mine lasted 4-5 years as a daily.

[///M TOWN]

Originally Posted by Pray for Mojo

Mine lasted 4-5 years as a daily.

I can see why it might last that long

I replaced one so I replaced the other at the same time

Interesting enough my 2nd key that was dead is the one I never use

[gphung]

2018 LCI, though second owner. My key #1 battery gave me a warning conveniently when I picked up my car from the dealer after dropping it off for CBS maintenance at the beginning of May this year. Curious if the dealership noticed lol.

I swapped my key #2 battery over and it's fine now, though I'm not sure how long it'll last. I never touch key #2 and also live in a condo where it's impossible for any unnecessary communication between my keys and car to occur.

[Tag]

Originally Posted by DanG

Got an interesting message from my BMW today. It said the key battery was critically low. Also showed a warning triangle on the dash.

I was quite surprised. I have never had to change a key battery on any of my previous BMWs and some I owned for over ten years.

I did find a YouTube video instructions. Luckily I had a 2450 battery at home. Replaced the battery and warring signs disappeared.

Anyone else had to replace their key battery?

The previous generation of bimmers (non-comfort access) fobs had rechargeable batteries in them. When you inserter the key into the holder it would automatically charge the battery which is why they lasted the life of most ownership. When they moved to the F chassis cars all fobs used disposable non-chargeable batteries. If purchased new the dealer likely replaced the battery at least once or twice when the car was in for service. Either way, the batteries are cheap and simple enough to replace.

[425M2]

I did just recently, real easy to do!

[jkoral]

Originally Posted by DanG

I was quite surprised. I have never had to change a key battery on any of my previous BMWs and some I owned for over ten years.

Did your other BMWs have comfort access?

I've also never replaced a battery in my previous BMWs, but none of my older BMWs had comfort access. In my most recent 135i, the key fob has a built in rechargeable ("non-replaceable") battery that recharges by induction when in the dash.

[DanG]

Originally Posted by jkoral

Did your other BMWs have comfort access?

I've also never replaced a battery in my previous BMWs, but none of my older BMWs had comfort access. In my most recent 135i, the key fob has a built in rechargeable ("non-replaceable") battery that recharges by induction when in the dash.

Yes the previous BMW to my M2 had comfort access.

[///M TOWN]

Originally Posted by gphung

2018 LCI, though second owner. My key #1 battery gave me a warning conveniently when I picked up my car from the dealer after dropping it off for CBS maintenance at the beginning of May this year. Curious if the dealership noticed lol.

I swapped my key #2 battery over and it's fine now, though I'm not sure how long it'll last. I never touch key #2 and also live in a condo where it's impossible for any unnecessary communication between my keys and car to occur.

My second (backup) key died that's stored in a Faraday cage pouch

So I replaced both batteries while I was at it

I chose lithium for longevity

[F87source]

Originally Posted by ///M TOWN

My second (backup) key died that's stored in a Faraday cage pouch

So I replaced both batteries while I was at it

I chose lithium for longevity

I store my second key w/o a battery so it doesn't chew them up for no reason. Also I've had the electrolytes leak out of old batteries before so I'm not interested in that occuring in my m2 key.

[///M TOWN]

Originally Posted by F87source

I store my second key w/o a battery so it doesn't chew them up for no reason. Also I've had the electrolytes leak out of old batteries before so I'm not interested in that occuring in my m2 key.

That's not a bad idea at all

Clearly the battery gets used up even if the key is never used

I also use lithium batteries on my door lock for my home they work really well and last a long time