To exchange the battery of your Beoplay H9i, follow the steps listed below:
Open the battery compartment
• Turn the left earphone metal cover counter-clockwise to open the battery compartment.
Remove the metal cover
• If needed, press down on the cover edge near the microphone to release it.
Remove the battery
• Press the button at the bottom of the compartment.
Replace the battery and close the metal cover
• Insert the replacement battery with the marker pointing upward.
• Close the metal cover, making sure to align the mark inside the headphones with the mark on the cap
• Turn the metal cover clockwise to lock it.