The Polar H1 and H7 Heart Rate Sensors take one CR2025, which is a 3-volt lithium coin cell battery.
Note: The Polar H1 Heart Rate Sensor was previously called the Polar Wearlink chest belt.
The battery should last about two years at one hour of use every day.
- Using a coin, open the battery cover by turning it counterclockwise to OPEN (see image at right).
- Insert the battery (CR2025) inside the cover with the positive (+) side against the cover. Make sure the sealing ring is in the groove to ensure water resistance.
- Press the cover back into the connector. Use the coin to turn the cover clockwise to CLOSE.