The Honeywell thermostat is a device installed in your house that controls the overall temperature of your home. You can program a specific temperature range, or you can select a designated temperature for the house. The thermostat does run on batteries though, so you will eventually have to change the batteries.
Look for the battery cover on the left side of the Honeywell Thermostat. You can see an outline of where the battery cover can be removed from the rest of the thermostat.
Pull up from the bottom of the battery cover. If you do not have long enough fingers or can't get a grip, you can use a coin or key in the opening at the bottom of the battery cover to help pull it up.
Remove the cover, and take out the old batteries.
Insert the new AA batteries into place. Make sure the positive and negative side of the batteries are aligned properly. On the inside of the battery case is a diagram of a plus and minus symbol next to where the batteries should be placed.
Slide the battery cover back into place.