I don't know man, I just listened to 60 minutes of Mozart (violin concertos 1 and 2 by Isabella Steinbacher) in the highest possible resolution (master) - DSD256, in tube mode medium (sound volume 75 !!!) and the charge dropped by 22%. That means at least 4 hours of music in the highest possible resolution, the best sound quality in the world (probably) in tube mode. At the beginning, after a full charge after a day or two of not working, when turned on, my player showed a charge lower by 15-20 percent, just like that. I thought something was wrong with it. But after several cycles of full charge and discharge, everything changed. Maybe you should give it a try again.