# Electric power |  | **Electric power** is the transfer of electrical energy within a circuit. Its SI unit is the watt, the general unit of power, defined as one joule per second. Standard prefixes apply to watts as with other SI units: thousands, millions and billions of watts are called kilowatts, megawatts and gigawatts respectively. | |-|-| | | wikipedia:: [Electric power](https://en.wikipedia.org/wiki/Electric_power) | [[Electric battery]] [[Solar power]] [[Anode]] [[Cathode]] [[Electrolyte]] Watt hours - Wh mAh = miliamps hours > How to convert mAh into Wh (Watt Hours) > > While mAh only suggests "two dimensions" of capacity, Wh is a solid "three dimensions" figure that calculates battery capacity as a whole. > > Ah * V = Wh > > You may not have heard of AH before. > > Don't feel stressed about another unknown terminology. > > Ah is just a different unit that is equal to 1000mAh > > For a 3.7V 2600mAh battery, the Wh will be: > > 2600mAh * 3.7V > > 2.6 Ah * 3.7V = 9.62 Wh > > So now we know the energy of a 3.7V 2600mAh battery is 9.62Wh.