Sportline Solo 900 Heart Rate Monitor Watch
Remove the battery cover on the back of the watch using a coin or a small screwdriver designed for jewelry and watches.
Pop out the battery with your finger or a small screwdriver.
Insert a standard 2025 lithium replacement battery with the positive side facing the battery cover.
Gently bend the spring on the battery cover to apply more pressure to the battery. Increasing the pressure will help the battery contact the watch correctly and ensure the watch functions properly.
Replace the battery cover.