RE: Lipo not fully charging
The battery most probably had some energy still stored within it. If so it will only charge so that the residual plus what you now input to it is enough to fill it up. If the final voltage was 4.2 volts/cell, it was fully charged. Note that the 4.2 volt/cell value is not 100 percent accurate as the true value will vary slightly with temperature but should be very close to that value.