The OH1 battery is empty, and I cannot start a new training session
If the battery of your OH1 is completely empty and you have a training session stored on it, you need to sync the training session to Polar Flow via computer or mobile before you can start a new training session. The red LED will blink to indicate you cannot start a new session.
After syncing the training session you can start a new training session. See Syncing for details.