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