Date/Time Battery Failure, 1D Mark III

According to the manual, the CR-2025 lithium battery that saves the date/time settings is supposed to last about 5 years. Mine failed a few months ago, definitely earlier than the 5 years they claim. I put in a new one, and it has failed again.

I will replace it one more time, hoping the new battery just happened to be bad, but I'm wondering if anyone else has had a similar problem. Maybe there's something in the camera that's causing an increased draw on the battery or something.

Thanks.

Is it actually the battery that's drained, or do you have a bad contact in the camera?
Measure the voltage of the battery with a DVM.

Very possibly right about getting a pre-drained "new" battery. The last 5-pack of maxells I bought were almost all failures. Hit and miss. At only $2 each for the good stuff, it's a limited investment to keep in supply...