Volt - Common Voltages

Common Voltages

Nominal voltages of familiar sources:

• Nerve cell resting potential: around −75 mV
• Single-cell, rechargeable NiMH or NiCd battery: 1.2 V
• Mercury battery: 1.355 V
• Single-cell, non-rechargeable alkaline battery (e.g., AAA, AA, C and D cells): 1.5 V
• LiFePO₄ rechargeable battery: 3.3 V
• Lithium polymer rechargeable battery: 3.75 V (see Rechargeable battery#Table of rechargeable battery technologies)
• Transistor-transistor logic/CMOS (TTL) power supply: 5 V
• USB: 5 V DC
• PP3 battery: 9 V
• Automobile electrical system: nominal 12 V, about 11.8 V discharged, 12.8 V charged, and 13.8–14.4 V while charging (vehicle running).
• Household mains electricity: 230 V RMS in Europe, Asia and Africa, 120 V RMS in North America, 100 V RMS in Japan (see List of countries with mains power plugs, voltages and frequencies)
• Trucks/lorries: 24 V DC
• Rapid transit third rail: 600–750 V (see List of current systems for electric rail traction)
• High-speed train overhead power lines: 25 kV RMS at 50 Hz, but see the list of current systems for electric rail traction and 25 kV at 60 Hz for exceptions.
• High-voltage electric power transmission lines: 110 kV RMS and up (1.15 MV RMS was the record as of 2005)
• Lightning: Varies greatly, often around 100 MV.

Note: Where RMS (root mean square) is stated above, the peak voltage is times greater than the RMS voltage for a sinusoidal signal centered around zero voltage.