It’s tough enough needing a kid with 20:20 vision to read the information on a AAA battery. Things get worse when they demand to know “what’s a watt hour and why.” We thought it was time to define the difference between Watts and Amps. Then we can shop with more confidence and purchase the right battery for our device.
The Difference Between Watts Defines Power Capacity
Watts are the rate that energy flows through a circuit, in our case a battery. We also compare light bulb brightness in terms of the difference between Watts. This is because more energy causes them to burn brighter. However, this does not tell us how much energy will flow over time.
We find the solution for that puzzle in the second unit of measurement, namely Amps. These are the amount of electrical current the circuit can deliver. It is important to relate the resistance in a device to this. Or else, to continue the example the light bulb may burn out, or just glow dimly.
Bringing Power Capacity and Power Capability Together
Watts are the raw capacity of the battery. The difference between Watts and Amps is the latter is the capability, or rate of delivery. We can combine these in this calculation: Amps x Watts = Watt Hours (Wh). This unit of measurement also frequently appears on batteries as Amp Hours (Ah).
It’s time to draw these somewhat confusing threads together about how electricity flows in electrical circuits. We’ll use the Water Flow Analogy to help us understand this better. In a plumbing system, Amps would be the volume of water in the pipes. Whereas Watts would be the water pressure.
Finally, it’s important to note why we define the rate of delivery per hour. This is because we need a standard time-measurement-unit to be able to compare. However, we do need to remember that Amp hours and Watt hours are the maximum delivery rate a battery can manage. And that it will run out of energy rapidly if we drain it at that rate.
Related
Water Flow Analogy of Electricity
Amp-hours, Current, Watts & A Coffee Pot
Preview Image: Lovely Little Glowing LED’s
