Heart rate sensor batteries
The Polar H10/H9/H7 heart rate sensor has a user changeable battery. Average battery lifetime of a heart rate sensor can be found in the product user manual.
You can change the sensor battery yourself. If you'd like help, please contact your closest Polar Service Center to have it changed for you.
To change battery yourself, see the instruction video for H10/H9 or H7 or check out your sensor user manual for instructions.