Charging the Osmo Action battery is a pretty simple task, and can be done with either a USB power bank or wall charger.
How To Charge Osmo Action
To charge the osmo action, you'll need to have the USB-C cable & USB power brick or power bank or computer. A USB C cable came in the original box. Under the USB-C / Micro SD card slot door on the side, you'll put the USB-C end in the slot and the other end to your wall, power bank or computer.
How Long Does It Take To Charge The Osmo Action
The Osmo Action takes about 90 minutes to go from completley depleted battery to a fully charged battery. The Osmo Action currently does NOT support fast charging unfortunately. Hopefully the Osmo Action 2 will!
Osmo Action Battery Life
While starting from a fully charged battery, the Osmo Action will have about 60-90 minutes on a single charge shooting 4K/24fps video with RockSteady turned off. You can film for 135 minutes filming 1080/30fps with RockSteady turned off as well. The higher the resolution and enabling RockSteady will shorten the overall battery life.
Turning off the backlight on the screen while recording will help you extend your battery life here! If you need to frame up your shots, keeping the backlight on will be helpful here - but just understand that will impact your battery life.