Key fob battery

[Rolfe]

Just a couple of days after my car's third birthday (and at about 31,500 miles) I got a low key battery warning on the dashboard. I just popped a new battery into the fob and all seems well. Is this the sort of life span others have been experiencing?

 

[MG Clive]

The keyfob battery is supposed to be changed every two years when it's serviced, so MG must reckon on a less than three year lifespan.

 

[siteguru]

At 2nd service I gave the dealer both my keys, on the basis that the batteries were supposed to be changed. Whether or not they actually did I've no idea, but I've not had any such warnings, and my car is ~6 months old than @Rolfe's.

 

[Rolfe]

I have never given both keys to a dealer. The other key, which I was using day-to-day, had an accident within the past year, and so what I'm using now is the one the dealer never had while the car was being serviced. Well, OK that's not true, Central Garages had it a few days before that for its third service, but obviously didn't do anything with it.

Anyway, it only takes a couple of minutes to pop a new battery in. I just wondered if three years was par for the course.

 

[Everest]

I just wondered if three years was par for the course.

IME yep.

 

[Rolfe]

Thanks.

Beats the other key fob, in which a battery lasts three DAYS since its accident.

 

[Lovemyev]

I just wondered if three years was par for the course.

Sounds about right tbh, but it does vary from manufacturer to manufacturer and even down to different models !.
I have owned about 6 new VAG models and the fob batteries lasted over three years, but our last VW was a Golf GTE PHEV with the keyless entry system.
It’s a strange design because the key sends a message to the car brain every few seconds when the car is in use.
You can see this happening, because there is a small red led light in the fob, that blinks every 5 to 10 seconds.
As a result of this constant drain, it eats through fob batteries about every 12 months.
The shortest time was 7 months !!!.
Spoke to the master tech at VW and he said that it was common with this type of system.
He also advised me to replace the battery as soon as you get the message on the dash.

 

[wandle MG4]

It’s reassuring a message comes up on the dash alerting you to a low battery.

I handed both fobs over at the 2 year service and discretely marked the batteries. They were both swapped for new ones.

It’s worth checking the blade key is still present every time a dealer has had the fob.