What should I do if Amazfit Band 2 fails to upgrade?

1) Click the Retry button on the page to re-upgrade. 2) When the band is connected with Amazfit App, pull down the synchronous data on the status home page to trigger an upgrade. 3) Switch off and then turn on the mobile phone Bluetooth, and re-open Amazfit App to connect with the band for an upgrade. 

Notes: Please keep the remaining battery capacity over 10% when you upgrade the band. An upgrading is unavailable when the remaining battery capacity is below 10%.