Thanks for doing the research for me, schmidtj. I was thinking of putting a piece of cellophane between the battery and the contacts on my second FOB and carrying it inside the car as an emergency back-up.

I was afraid of doing this would cause the FOB to eventually become useless. From what you are saying and per that article you pointed out in Wikipedia, I think I will do just what I had in mind.

I've never felt secure without a spare key somewhere within the car. With the FOB, I thought I was out of luck. But, with the FOB (without the battery connected) inside the car and the detachable key secured outside the car, I will once again have the security of a backup key for emergencies.

Thanks again for the explanations.