6.How to check whether the player's battery life is normal?

A: 1. Fully charge the player.   
    2. Go to System Settings->Reset factory defaults (thus also resetting the volume to default)
    3. Connect a pair of earphones with 32 ohms rated impedance.
    4. Download the test track (>>click to download) to the player, then set the play mode to "loop single" and start playing.
    5. Measure the battery life from the time the player starts playing to the time when the player runs out of battery and shuts down automatically.
The X3MKIII, X5 2nd gen, X3 2nd gen, X1 2nd gne, X1, X3 and X5 are both rated for about 10 hours in such reference conditions. It is normal for the battery life to be somewhat shorter than 10 hours if earphones of less than 32 ohms are used or somewhat longer than 10 hours if earphones of more than 32 ohms are used.

For the X7, the battery life is different when with the different headamp modules.
(The following test results are for reference.)