I'm using the charger that came in the box with the phone. It used to always charge on AC when plugged into a wall. Then it started charging as USB SOMETIMES when plugged into an outlet, but you could get it back to AC just by unpligging and re-plugging it in. Now it ONLY charges in USB mode, which obviously takes forver. What the ****? I've only had it 8 months. No warranty I know of or insurance, so please don't just tell to replace it. That would mean buying a new phone.