Remote key fob battery going flat

[Stardelta]

Hi all...I have a s204 Mercedes c220 cdi 2008 and have a problem with one of the key fobs in the fact that it discharges both lithium cr2025 batteries in around a week with the key fob not in use sitting on the table, do have a spare that is fully working and have swapped over the inner part that houses the batteries and that made no difference, so obviously it is the key fob outer housing that is causing the problem.
I have pointed the key at my digital camera to see if any of the buttons are depressed but all ok, can push all three one at a time and see the infra red flash on my camera screen, also tried three different sets of batteries from different manufacturers and from shops not eBay.
Do any of you have a answer or encountered this before, was thinking about buying a key fob from eBay and changing the outer, would this work?

 

[bob6600]

Cheap batteries definitely don't last but this does not seem to be your issue as you have stated. Unfortunately you cannot just buy a key from eBay either. Have a word with www.replacementmercedeskeys.co.uk they know their stuff and should be able to advise you better.

 

[Stardelta]

Many thanks for the website, looks a good company and will give them a ring for advice today