So, yesterday my fully charged ZX1 played line out to a headphone amp. Volume on the ZX1 = max.
After maybe 3 hours it was down to 15% and it was really hot! I connected the charger but it still told me "connect your charger".
The player get's two years old in a few days.
I tried different cables and power supplies but it didn't charge. It stayed on the 15% battery level with the cable connected but it stayed very hot!
The question: Should I exchange it for a new ZX1 or better get a ZX100?
Did somebody already found out how to disassemble the ZX1 to replace the battery?
Before doing anything else, I would recommend allowing the ZX1 to continue to play until it performs its own automatic "emergency" power off. It's possible you're just experiencing a discrepancy between how much charge is left in the battery versus how much charge the operating system thinks it has. Allowing the system to play until it turns itself off will help realign that battery calibration.
I'd probably suggest looping a movie with the screen on and turned to max brightness, so it wears out as quickly as possible.