The good news is that you can buy little adapters that show charging stats to help identify the problem. They’re called power meters, and they’re fairly inexpensive. USB power meters are pretty simple ...

A meter to measure the electrical parameters ... along with the calculated power, on the small 0.5″ OLED display. The circuit is built around an ATmega328. To keep the board size small, and ...

[Chris] tried his hand at using Optical Character Recognition in his server power monitoring rig ... We gather that the meter can show varying degrees of precision based on the total number ...