take all I say with a grain of salt because I don't own this model. the usual rule of thumb with sony is that each DSP will remove between 30 and up to 60% of battery life. and then if you use several, the effect adds up. of course there is also some part related to what headphone/IEM you're driving and how loud, but if you stick to portable gears that shouldn't be too massive of a difference. how long the screen stays ON will also have some significance in the long run. the last aspect is the file being played, you probably have some small information on all that somewhere on a PDF online. if you want to check if maybe your battery is defective, go turn off everything you can find, from volume normalizer, clear audio, EQ... play something like mp3 or 16/44 flac, and count how long you last on one charge. otherwise your results won't mean much.