Sony WF-1000XM4 Manual page 29

When the headset is removed from the charging case or the lid of the charging case is opened or closed when the
charging case is empty, if the indicator (orange) on the charging case lights up, the remaining battery charge of the
charging case is approximately at 30% to 1%. The charging case cannot sufficiently charge the headset with this
level of remaining battery charge.
When the headset is removed from the charging case or the lid of the charging case is opened or closed when the
charging case is empty, if the indicator on the charging case does not light up, the remaining battery charge of the
charging case is at 0%. The headset cannot be charged with the charging case in this case.
Hint
You can also check the remaining battery charge of the headset and the charging case with the "Sony | Headphones Connect"
app. Android smartphones and iPhone/iPod touch both support this app.
Note
The remaining battery charge may not be properly displayed immediately after a software update or if the headset has not been
used for a long time. In this case, repeatedly charge and discharge the battery multiple times to properly display the remaining
battery charge.
Related Topic
What you can do with the "Sony | Headphones Connect" app
About the indicator
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