Smart Key Battery

[Nitecard]

Apologies if this has been asked before, but I can't find the discussion I thought I had seen.

My 2015 C250 keys devours batteries, the last one lasted a week before I get the warning
that the battery needs changing.

When I checked the battery it read 3V and this has been the case previously.

Can anyone suggest the problem?

Thanks in anticipation.

 

[onefortheroad]

Use Duracell??

 

[Jason63]

You can't really check lithium coin cells with a voltmeter. The voltage may seem fine but the battery can be dead.

It's possible you have a duff batch of batteries or if you have comfort access perhaps the key is within range of the car.

 

[John Laidlaw]

As above, buy proper Duracell, Panasonic or Varta batteries, not from the pound shop, those last just days

 

[Nitecard]

Thanks for your advice.

I have used Excell batteries for years and always found them to be ok and this is what I have in my key, I will try a Duracell as you suggest.