Originally Posted by Dave9
^ It depends on the design of the fob, whether it would work with one 2032 at that halved voltage. You will not ruin the fob with too low a voltage, but if it were designed for one cell and you stacked two, it is quite possible that higher than design voltage could cause damage.
If you put a half voltage single cell in and it works, it will still stop working sooner because the voltage will drop too low. I don't see it as being worth bothering to do because those little batteries are pretty inexpensive on ebay and tend to last years, as long as you are buying factory fresh rather than new old stock.
Sorry I should of come back here and updated this, i really hate reading thru a thread with no real ending.
I tried sticking a new 2032 and it didn't work consistently and lost to much range. I can normally stand in my kitchen at the back of the house and it will start my truck parked out on the street, guessing a little over a hundred feet. With the 2032 I had to walk to the front of the house by a window before it would work. So I ordered a couple 2016's from amazon and all is back to normal.
The thing that blew me away is how long the Panasonic batteries lasted that came with it, almost 5 years. The other remote is still working on the original batteries, if I get half that out of the Energizers I'll be happy.