Electric Charge
About Electric Charge Conversion
Electric charge is a fundamental property of matter that causes it to experience electromagnetic force. It's measured as the quantity of electricity, the amount of charge that flows or is stored. Charge comes in two types (positive and negative), carried by protons and electrons respectively, with opposite charges attracting and like charges repelling. This basic property underlies all electrical phenomena from static electricity to chemical bonds to electronic devices.
The SI unit is the coulomb (C), defined as the charge transported by one ampere of current in one second. However, ampere-hours (Ah) and milliampere-hours (mAh) are more common for batteries because they directly relate to how long a battery can supply current at a given rate. Understanding the relationship between charge (Ah) and energy (Wh) is essential for proper battery sizing. You must account for voltage to compare batteries meaningfully.
Our converter handles all standard electric charge units for electronics, battery applications, and electrochemistry calculations.
Common Electric Charge Conversions
| From | To | Multiply By |
|---|---|---|
| Ah | C | 3,600 |
| C | Ah | 0.000278 |
| mAh | Ah | 0.001 |
| Ah | mAh | 1,000 |
| mAh | C | 3.6 |
| C | mAh | 0.278 |
| C | μC (microcoulomb) | 10⁶ |
| C | elementary charges (e) | 6.242 × 10¹⁸ |
| Faraday | C | 96,485 |
Electric Charge Unit Reference
Coulomb (C) – The SI unit of electric charge, named after Charles-Augustin de Coulomb who quantified electrostatic force. One coulomb equals the charge transported by one ampere of current flowing for one second (1 C = 1 A·s). This represents about 6.24 × 10¹⁸ elementary charges (electrons or protons). A typical lightning bolt transfers 15-350 coulombs. A static shock involves microcoulombs.
Ampere-hour (Ah) – One ampere flowing for one hour, equal to 3,600 coulombs. The standard capacity unit for larger batteries: car batteries (50-100 Ah), power tool batteries (2-12 Ah), e-bike batteries (10-20 Ah). To calculate runtime: hours = Ah ÷ current draw. Capacity depends on discharge rate. Manufacturers often specify C-rate conditions.
Milliampere-hour (mAh) – 1/1000 of an Ah (3.6 coulombs). Universal specification for portable device batteries. Smartphones: 3,000-5,000 mAh. Tablets: 5,000-15,000 mAh. AA alkaline: ~2,500 mAh. 18650 lithium cells: 2,500-3,500 mAh. Always compare batteries at the same voltage. Energy (Wh) is more meaningful across different voltages.
Elementary charge (e) – The fundamental unit of charge, equal to the charge of one proton (or the magnitude of one electron's charge). 1 e = 1.602176634 × 10⁻¹⁹ C exactly (defined value since 2019). All observable charges are integer multiples of e. Quarks carry fractional charges (⅓e, ⅔e) but are never observed free.
Faraday (F) – The charge of one mole of electrons, equal to 96,485.33 C (Avogadro's number × elementary charge). Essential for electrochemistry: plating one mole of a monovalent metal requires one faraday. Named after Michael Faraday who established electrolysis laws.