iPhone 5s massive battery drain

[KaHo]

My using experience:

I went to bed and started to listen to the music by Spotify(offline mode), 

but when I waked up in the morning, it used all the battery from 100% to 0%...

I tired twice, it's just the same. 

I can only say, this app is great but the battery usuage is also great, sad. 

Please fix it! 

[Peter__]

Over approximately how many hours would you say you where asleep? Also, have you enabled offline mode in the settings or are you listening to an offline playlist but online?