Unit cAh centiampere-hour Electric Charge A centiampere-hour (cAh) is a unit of electric charge used to measure battery capacity, particularly in smaller devices or batteries. It is derived from the unit ampere-hour (Ah), which is commonly used for larger batteries. An ampere-hour is a measure of the amount of electric charge that a battery can deliver over an hour. It is calculated as the product of electric current (the flow of electric charge measured in amperes, A) and time (measured in hours, h). A battery rated as 1 Ah can deliver a constant current of 1A for 1 hour, or 0.5A for 2 hours, or 2A for 0.5 hours, and so on. A centiampere-hour is defined as 1/100 of an ampere-hour (1 cAh = 0.01 Ah), which means it is a smaller unit used for expressing the capacity of smaller batteries, such as coin cell batteries found in some electronic devices. For example, a battery with a capacity of 20 cAh can deliver a steady current of 20 centiamperes (0.2 A) for 1 hour, or 10 centiamperes (0.1 A) for 2 hours, or 40 centiamperes (0.4 A) for 0.5 hours, etc. In summary, the unit centiampere-hour (cAh) is a unit of electric charge used to express the capacity of smaller batteries, indicating the amount of electric charge they can deliver over time.