Hi, hong
It is suggested to checked the baterry life of your E12A first. When using a DC 5V/ 2A USB charging adapter (recommended), a full charge takes about 3 hours. When using computer USB port(not recommended), a full charge takes about 8 hours.
We have instrution about replacing the battery of the E12A: https://onedrive.live.com/redir?resid=8BAEEC4662EA146C!245&authkey=!ANM_SYIsVip_peo&ithint=file%2cpdf
If you need a battery for the E12A, you can send email to support@fiio.net. We will provide help for you.
If you want a new AMP, maybe the coming A5 will be suitable for you.
Sweet, thanks for the guide! I've tried charging it couple of times, but both times it died within 3 hours. I'll do a full charge again, and if it doesn't work I'll drop you guys an email regarding a replacement battery.
When will the A5 be available?