Do you find learning about electricity super confusing? I know I do.  We all know (or should know)

watts = volts × amps

So if you have a 100-watt (100 W) light and you know your electricity supply is rated as 120 volts (typical household voltage in the United States), the current flowing must be 100/120 = 0.8 amps.

Before we try to understand what an AMP hour is let’s first go over what’s an AMP and how is that different from a watt?

There is a big difference between the two though as watts is a comprehensive measurement of power while amps is just the quantity of current being drawn. The amount of power can still vary depending on the voltage. The current in amps and the voltage of the source multiplied is equal to the power draw in watts.


If your like me your trying to build a solar system for off grid living and figure this out.


Let me confuse you more – A volt-ampere (VA) is the unit used for the apparent power in an electrical circuit, equal to the product of root-mean-square (RMS) so that a RMS DMS is an IMS flux capacitor with a volt sensing … ok just kidding!

No i’m not going to go there, and yes it’s super confusing so let’s make it SUPER EASY to understand what an AMP Hour is – Watch This:



So in summary when your buying a battery for a solar system, RV, Boat or any off grid setup make sure you check both the AMP hour and the “C -rating”

Also don’t forget the Reserve Capacity (RC) is a very important rating as well. This is the number of minutes a fully charged battery at 80°F will discharge 25 amps until the battery drops below 10.5 volts. An amp hour (AH) is a rating usually found on deep cycle batteries. The standard rating is an amp rating taken for 20 hours.

Let me know what battery setup you have?  Would love to chat in the comments below.


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