The Withings Activité Pop uses a standard, non-rechargeable CR2025 coin cell battery. WHICH ONE BEEN REPLACED.
To set up the watch, you need to download the Withings app on your phone. During pairing, you will need to press the small button on the back of the watch. After pressing it, you should feel a vibration. I have disconnected the watch from my account.
If you need to reset the watch, press the reset button on the back 5 times.
You should feel a slight vibration with each press.
On the 5th press, the watch will vibrate twice, confirming the reset is complete