An ampere-hour or amp-hour (symbol Ah, AHr, A·h, A h) is a unit
of electric charge, with sub-units milliampere-hour (mAh) and
milliampere second (mAs). One ampere-hour is equal to 3600
coulombs. The ampere-hour is frequently used in measurements of
electrochemical systems such as electroplating and electrical
batteries. The commonly seen milliampere-hour (mAh or mA·h) is
one-thousandth of an ampere-hour (3.6 coulombs). A milliampere
second (mAs or mA·s) is a unit of measure used in X-ray imaging
diagnostic imaging and radiation therapy. This quantity is
proportional to the total X-ray energy produced by a given X-ray
tube operated at a particular voltage. The same total dose can
be delivered in different time periods depending on the X-ray
tube current. An ampere-hour is not a unit of energy. In a
battery system, for example, accurate calculation of the energy
delivered requires integration of the power delivered (product
of instantaneous voltage and instantaneous current) over the
discharge interval. General