Sony Cyber-shot DSC-W310 Instruction Manual page 26

On the internal rechargeable backup battery
This canlel'a has all internal rechargeable battery for maintaining the date and time
and other settings regardless nf whether the power is on or nff.
Tbis rechargeable battery is continually cbarged as lnng its ynn are using the camera.
However, if you use tbe camera for only short periods, it discharges gradually, and if
you do not use tbe camera at all lor about one month it becomes completely
discharged. In this case, be sure to charge this rechargeable battery before using tile
camera.
However, even if this rechargeable battery is not charged, you can still use the
camera, but the date and time will not be indicated.
Charging method of the internal rechargeable backup battery
Insert a charged batter_ pack in tile camera, and then leave tile camera lor 24 hours
nr more with tile power off.
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