Are there thermostats without batteries? Sick of constantly changing batteries

Sure -- the old fashioned non-programmable ones don't require batteries (unless it has a digital display).

Once a year is constantly replacing them? Actuallyt they last much longer than a year....if you wait until they die. I can get a year and a half out of my programible on a set of regular copper top durcells....maybe even longer with the red top ones or the litium.

Most digital thermostats can be powered from the system.