[Tom Wells]

Dan,

Just a shot in the dark - I don't have an Excalibur so I don't know what the fobs you have look like.

If they're like others, they may have a small, button battery in each one. These are inexpensive, widely available and easily replaced. Mine can be popped open with a plastic upholstery spoon (kinda like a stiff credit card) and the rest should be pretty obvious. Some auto parts stores know how to deal with them too.

Could you provide a picture of one?

Tom