Sony NW-ZX100 Help Manual page 272

Even if the player is turned off for an extended period, a small amount of battery power is still consumed.
Battery life may vary depending on volume setting, conditions of use and ambient temperature.
When [Brightness] is set to [5], the battery life is about 40 % shorter than when it is set to [3].
When more than one of the sound quality settings is enabled, the battery life is about 50 % shorter than when all
sound quality settings are disabled.
The battery life for continuous playback via a Bluetooth connection may become 40 % to 70 % shorter depending on
the content format or the settings of the connected device.
4-573-375-12(1)
Copyright 2015 Sony Corporation
261