Thermostat has very short battery life
The battery life of a thermostat depends on a few factors. Verify the following if a thermostat is experiencing short battery life.
Note: Thermostats using AC power still occasionally receive Low Battery alerts due to their role as a backup power source. If these alerts appear frequently for an AC-powered thermostat, troubleshoot using the following steps.
Verify the thermostat uses recommended batteries
It is recommended that all thermostats use high-quality, brand name, alkaline batteries. Verify the thermostat is using the recommended batteries with a strong charge.
Verify the thermostat enrollment
There may be issues if the thermostat was enrolled using AC power but now solely relies on battery power. If the thermostat has a C wire, verify this by removing the batteries, placing the thermostat on the wall, and attempting to press a button. If it doesn't light up, the C wire may not be connected properly.
It can also help to delete and re-add the thermostat off of the wall to make sure it enrolls on battery.
Z-Wave communication issues
When Z-Wave communication is poor, the thermostat uses more power attempting to connect to the controller. Verify that the thermostat has a consistent Z-Wave connection.
For more information, see What is the range of Z-Wave? and What is Z-Wave interference?.