## Amps, Volts, Watts and WattHours - 101

This article contains the basic Formulas you need to understand electricity as well as two analogies to help beginners understand.

Watts = Amps * Volts {can also be written Power= current x voltage}

Amps = Watts / Volts

Volts = Watts / Amps

Watt-Hours = Volts * Amp-Hours {or energy = voltage x current x time}

To create voltage, magnets are used. The magnets strip electrons from atoms. As the electrons accumulate a negative charge builds. Likewise, the atoms with the missing electron accumulate on the other side and this becomes a positive charge.

In a battery, the - side of the battery is an accumulation of electrons. The + side is an accumulation of atoms with an electron missing. Electrons are strongly attracted to the atoms just as magnets attract. This is the magic that makes it all happen!

Amps are defined as a certain number of electrons passing a given point in a given amount of time. (1 Amp = 6.24 * 10^18 electrons per second past a given point)

Or use the analogy of water spraying out of a pipe onto the watermill paddle wheel. High volume low pressure will spin the mill wheel as fast as low volume and high pressure.

So Watts are equal to volts * amps. To measure the total power (or liters) delivered, you specify the power level

i.e. kilowatt-hours or total energy consumed.

Notice also that if you increase the pressure in the pipe (or voltage in the wire), the flow (current) will increase. Therefore, your power also increases. Put another way, if you increase the pressure (voltage), you can deliver more water (electricity) with a smaller pipe (wire). That's why electric power transmission over any distance is done at higher voltages, not at the much lower voltages typically seen by end users.

We hope this clears up some basic electricity physics.

**Formulas:**Watts = Amps * Volts {can also be written Power= current x voltage}

Amps = Watts / Volts

Volts = Watts / Amps

Watt-Hours = Volts * Amp-Hours {or energy = voltage x current x time}

**Water analogy:****Voltage**is defined as*difference of potential*. The Volt is the SI unit of measurement of this potential. Voltage is analogous to water pressure in a pipe. Voltage is the electromotive force that moves the electrons through the wire. Increasing voltage increases current (electron) flow.To create voltage, magnets are used. The magnets strip electrons from atoms. As the electrons accumulate a negative charge builds. Likewise, the atoms with the missing electron accumulate on the other side and this becomes a positive charge.

In a battery, the - side of the battery is an accumulation of electrons. The + side is an accumulation of atoms with an electron missing. Electrons are strongly attracted to the atoms just as magnets attract. This is the magic that makes it all happen!

**Amps**(amperes) is a measurement of the flow of electrons in a wire, which is analogous to water's flow rate in a pipe like "liters per minute". 1 Amp = 1 Coulomb (SI unit measurement of electric charge) x 1 Second. In the above battery for example, Amperage is a measurement of the electrons moving from the - terminal, through the motor or other device, to the + terminal. Once the atom and electron combine, the atom becomes neutral thus has no charge. As this migration continues, the voltage is steadily decreasing as the electrons rejoin their atoms.Amps are defined as a certain number of electrons passing a given point in a given amount of time. (1 Amp = 6.24 * 10^18 electrons per second past a given point)

**Watts**, or the rate of power delivery. A watt is analogous to the energy or power like water in a watermill. If the same volume(amp) of water falls from a higher fall(volt) (like a 15 foot drop), it will produce more power than the same volume water from a lower fall (like a 3 foot drop).Or use the analogy of water spraying out of a pipe onto the watermill paddle wheel. High volume low pressure will spin the mill wheel as fast as low volume and high pressure.

So Watts are equal to volts * amps. To measure the total power (or liters) delivered, you specify the power level

*and*for how long -i.e. kilowatt-hours or total energy consumed.

Notice also that if you increase the pressure in the pipe (or voltage in the wire), the flow (current) will increase. Therefore, your power also increases. Put another way, if you increase the pressure (voltage), you can deliver more water (electricity) with a smaller pipe (wire). That's why electric power transmission over any distance is done at higher voltages, not at the much lower voltages typically seen by end users.

We hope this clears up some basic electricity physics.