An ampere hour or amp hour is a unit of electric charge, having dimensions of electric current multiplied by time, equal to the charge transferred by a steady current of one ampere flowing for one hour, or 3,600 coulombs. The commonly seen milliampere hour is one-thousandth of an ampere hour.

What does the letters AH mean on a battery?

Select Your Cordless Tools Wisely

The letters “Ah” or “AH”(“amp-hour” or “ampere-hour”) that you see on your battery essentially denote the charge capacity. ... For example, a 2.0ah battery draws 2 amps of power and you will need to recharge it after 60 minutes of continuous use (under ideal circumstances).

What is the difference between a 2.0 Ah battery and a 4.0 Ah battery?

A 2.0Ah battery pack will have five 3.6V cells – each with 2.0Ah capacity – connected in series, and a 4.0Ah pack will have two sets of five batteries connected in parallel.