For those who are unfamiliar with the terminology that accompanies power tool batteries, making the correct portable power decisions becomes that much more difficult. And since there are quite a few different terms that are somewhat unique to the world of power tool batteries, here are 3 that will make the battery selection process a little easier to understand:

1. Amp hours (Ah): A unit of electric charge that measures capacity. In power tool batteries, this is a very key measurement as it represents how long it can deliver a certain amount of charge before it runs out. The measurement milliAmp hour (mAh) is most commonly used to represent how much charge is left in a particular battery. It’s important to note that Amp hours don’t dictate the flow of electrons at any given moment, meaning that the actual length of time that an Amp-hour symbolizes can change depending on how efficiently the battery is being used.
2. Amps (A): Named after the French mathematician and physicist André-Marie Ampère, the Amp is a measure of the amount of electric charge passing a point per unit time. In power tool batteries, Amps measure the volume of electrons passing through a wire in a one second. One Amp equals 6.25 x 1018 electrons per second.
3. Volts (V): Named in honor of the Italian physicist Alessandro Volta, the volt is an electrical measure of energy potential. In power tool batteries, a volt represents the pressure being exerted by all of the electrons at the negative terminal of a battery as they try to move to the positive terminal.