Key not charging??

[YetiX]

I did a search and didn't come up with anything so...

I have an '01 3.0i. A couple of months ago one of my keys stopped working, i.e. it wouldn't lock or unlock the doors remotely. I figured the rechargeable battery in it had died so I switched to my other key. It worked for about 2 weeks and then it too stopped working. As a test, I put the X5 key in my 330's ignition overnight. The next morning it worked great and continued to work for about a week and then died.

I have thus figured out that my X5 is not charging the key for some reason. Has anyone else had this happen and know how to fix it?

Thanks in advance!!