I have a carrier programmable thermostat that is approx 3 years old.
The thermostat works fine, but the clock is not keeping time correctly
(losing about 15 minutes a day). There hasn't been any power outages
as none of my other clocks are affected.

I thought there might be a battery somewhere, but I took it off the
wall and don't see one (I believe it is powered by AC). Does anyone
know if there is a battery somewhere or does it probably need to be
replaced?

Thanks