nope, as i said before, it randomly shutdown
i give it try a several testing and observing some behaviours:
1. stay untouch all day, and it still on
2. just a click to power button, sometimes it's getting locked/wake up/still on, sometimes it turn off
3. when processing a heavy task, like opera mobile, several apps running in background, it turn off itself
4. light activity like side swiping, or click the notification bar, it turn off itself
I can't make sure what's wrong with this device.

And battery said: Good

Oh, i forgot something, i always get auto-booting as soon as i plug in the charger, which is strange, considering the normal behaviour when device is off and get charge is just get the battery icon in LPM and stays off.