Follow these steps to change your device's battery. 

Focus

Step 1

Open the device from the notch side

Step 2

Replace the battery with a new one (positive pole upward)

Step 3

Assemble the device and long press the button for 5 seconds to restart it

Find 3

Step 1

Open the device from the strap insert point

Step 2

Replace the battery with a new one (positive pole upward)

Step 3

Assemble the device and long press the button for 3 seconds to restart it