IS MEASURING INPUT CAPACITY DURING CHARGING OF VALUE?
Unfortunately this measurment is almost useless as the input capacity is not the retained capacity. Due to both thermal and chemical inefficiencies batteries require 20 to 60 percent excess charge. For instance if you are charging 600 mah battery at 60 ma it might take up to 16 hours to obtain full charge. It will never take just 10 hours since this would require ideal battery which we do not have. As the batteries age the internal resistance increases causing higher thermal loss and the excess charge must be increased. The above comments apply to fast charging as well. Since thermal losses are current squared multiplied by internal resistance of the battery the disparity between input and retained charge is even greater due to higher current during fast charging. The thermal losses described above occur also during discharging. At higher discharge current the apparent capacity is smaller than at lower discharge current. The difference will depend again on internal resistance of the ba
