For your reference, here are some details about troubleshooting upgrade failures:
1. If the Mi Fitness APP or device prompts upgrade failure, please try to restart the device and upgrade again;
2. Put the watch on the charger and upgrade again when the power is greater than 20%;
3. Reset the watch, repair it and try to upgrade again;
4. Try to change other cell phone and to upgrade the watch after re-binding;
5. If the upgrade still fails and the watch cannot be turned on, please contact after-sales service for processing.