What is difference between mAh and volt?

A milliamp-hour (mAh) is a measure of quality of a battery. It tells you how many hours the batter can provide one milliamp of current before it will die.

A volt is the unit of electric potential. AA, AAA, C, and D batteries are all 1.5 Volts. A 9 Volt is 9 Volts. Car batteries are 12 Volts.

AA's are typically rated in thousands of mAh. Cs and Ds are more, AAA and 9 Volts are typically less.

If you know the power that a device consumes [i.e. Remote, wireless game controller], you can calculate how long your batters will last in the following manner.

Time = [mAh / 1000] * [# of batteries * battery voltage] / device power

Ex:

Device is rated at 1W using 4 AA [1.5 Volt] batteries rated at 1000mAh.

Time = [ 1000mAh / 1000 ] * [4 * 1.5 Volts] / 1 W = 6 Hours