The Thermo works on two AAA (LR03) batteries and can operate for up to 2 years depending on the frequency of use.

When the battery level is getting low, it is time to change the batteries. To do so, perform the following steps:

1. Lift the magnetic cover of the battery compartment of your Thermo to open it.
   
2. Remove the old batteries and dispose of them in accordance with local regulations.
3. Place two new AAA (LR03) batteries in the compartment.
   Make sure you follow the polarity markings when placing the batteries.
4. Place the battery cover back.