For Smart Swim 2, the battery will last up to 14 hours between charges.

For Smart Swim 1, the battery will last up to 16 hours between charges. 

Because battery life is affected by how the device is used and other settings (including display brightness), the actual length of a charge will vary.

To preserve battery life, always be sure to power down your goggles once you've saved and synced your swim. If you forget, the auto-shutdown will kick in.

Charging the goggles

The charging cable provided in the box is for use with a USB port. The charging contacts on the cable are magnetic and will snap into place on the corresponding pins on the goggles. Before charging the goggles, ensure they are completely dry as the cable is not waterproof. 

The app will tell you the percentage of charge on the goggles if you have the goggles turned on and navigate to the "my goggles" screen. 

It should take roughly an hour to charge the goggles to 80% from 0%.