RFID keys
 

I am the second owner of my car and I was given 3 keys when I bought it, 2 with the remote buttons on them and one that is flat and is just for starting the car (no buttons on it). I always just one of the keys, but I know the other 2 are for the car since they still have the dealer tag on them and I had tested them when I got t he car. Anyway, I haven't used either for about 6 years and today I went to try them since my reguloar key has been acting flakey. Well, neither will work at all. Does the computer deactivate the codes if you don't use the keys for a while? Or is this a sign that the tumbler or something on the car is bad?

Simply
 

Because no one makes Solar Powered Keys/Remotes.

And Trust me I know NOTHING about MB's Security Key Systems.

BATTERIES in the Remotes need replacing (Then Something about Re-Syncing)

OR

Have the Dealer order New Keys FROM YOUR V.I.N. from the Texas Depot.