Typical Voltages – Batteries, Grid, Lightning

30-second summary

Typical Voltage

In physics, voltage is the difference in electric potential between two points.

Voltage, denoted by V, is defined as the amount of work energy needed to move a unit of electric charge from a reference point (a) to a specific point (b) in an electric field.

ΔV = V_a – V_b

To help compare different orders of magnitude, the following list describes typical voltage levels.

1.5V (DC) – A common open circuit voltage for non-rechargeable alkaline batteries (e.g. AAA, AA, and C cells). 

3.8V (DC) – Almost all smartphone batteries work at 3.8 volts. In order to make current flow from the charger to the battery, there must be a potential difference. Therefore battery chargers or USBs for almost all smartphones provide a voltage of 5V.

12V (DC) – A common voltage for automobile batteries is 12 volts (DC).110 – 120V (AC) – The most common electrical outlet in any home. The American continent uses a voltage of 110 to 120 volts (AC) while Europe, Asia, and Africa use 220 to 240 volts (AC). 

3kV – Voltage required to generate every 1mm of an electric arc. Air is a very bad conductor of electricity and has high dielectric strength. The dielectric strength of air is nearly 3000V/mm.

110kV – The voltage in electric power transmission lines used to distribute electricity from power stations can be several hundred times greater than consumer voltages, typically 110 to >500 kV (AC).

300 MV – A typical lightning flash is about 300 million Volts and about 30,000 Amps.