key battery

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...

Hi, I have a Mercedes ML320 W263 year 99 model. The central locking is not working remotely via the key fob and the central locking only lock and unlock the drivers door, if I need to lock all the doors I have to push the button on the centre console which locks all the doors, then lock the...

The battery in my key is on the way out, takes 10-20 attempts to finally open the car, but sometimes it works fine first time. I though the car charged the batter as you drove!? If I have to replace the battery, what battery does it take so I can get one first. Or can MB charge it? CLK 230...