Typical Voltages – Batteries, Grid, Lightning – en

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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.