Sony MDR-AS700BT - Manual (Page 30)

although charging is not complete.
Check for the following causes:
Ambient temperature exceeds the range of 5 °C – 35 °C (41 °F – 95 °F).
There is a problem with the battery.
In this case, charge again within the above-mentioned temperature range. If the
problem persists, consult your nearest Sony dealer.
Notes
If the headset is not used for a long time, the battery may be quickly depleted,
however, after a few recharges, the battery life will improve.
Even if you do not intend to use the headset for a long time, charge the battery
to its full capacity once every 6 months to maintain its performance.
If the headset is not used for a long time, it may take longer to charge the
battery.
If the life of the built-in rechargeable battery drops to half the normal length, the
battery should be replaced. Consult your nearest Sony dealer for replacement of
the rechargeable battery.
Avoid exposure to temperature extremes, direct sunlight, moisture, sand, dust or
mechanical shock. Never leave the headset in a car parked in the sun.
If the computer enters into hibernation mode while connected to the headset,
charging will not be completed properly. Check the setting of the computer
before charging. The indicator (red) will go off automatically even if the computer
enters into hibernation mode. Charge the headset again in this case.
Use the supplied micro-USB cable only, and connect directly to a computer.
Charging will not be completed properly by an indirect connection, such as via a
USB hub.
Usage hours
Status
Approx. usage
hours
Communication time (including music playback time) (up
to)
9 hours
30