Battery Full by AC adaptor but Battery Charging via USB?

[kite7]

I am confused here. Which one is telling the truth? Is it possible that my AC adapter has gone bad or some circuitry in my D2 became faulty at detecting battery capacity?

I'm going to leave it in the USB and see if it ever says Battery Full

[swstar]

Nope, you won't get full charge with USB, that is just an icon telling you your battery can get electricity from USB.

But the best way to charge your device is via the wall charger.

[ProDigit]

It goes about twice faster via wall charger, but the D2 gets kinda warm when charging.
The USB doesn't support quickcharge.

[ManchesterBaby]

According to this http://www.batteryuniversity.com/parttwo-34.htm faster charge and discharge rates reduce the lifetime of a lithium-ion battery. So, in theory, your D2's battery may last longer if you charge with USB instead of the AC adapter...