Your phone battery moves more electric charge than a big lightning bolt
A typical lightning strike carries about 15 coulombs of charge, and even a monster bolt tops out near 350. A standard smartphone battery holds around 10,800. The difference is speed: lightning dumps its charge in an instant, while the phone doles out its supply gently over a day.
The coulomb is the SI unit of electric charge: the amount delivered when a current of one ampere flows for one second. Everyday quantities span a huge range. The spark from rubbing a balloon on your hair involves only a few millionths of a coulomb, an alkaline AA cell pushes about 5,000 through a circuit from full to flat, and one ampere hour, the unit printed on many batteries, equals 3,600 coulombs.
At the other end of the scale sits the elementary charge, the charge on a single proton. Since the 2019 overhaul of the SI it has been fixed at exactly 1.602176634×10^-19 coulombs, which makes a coulomb roughly 6.24 billion billion elementary charges. Oddly, the conversion never comes out even: a coulomb is not a whole-number multiple of the charge on one proton, so the decimal can be extended forever.
Chemists count charge in bigger bundles. A mole of elementary charges, about 6.022×10^23 of them, is called a faraday and is worth roughly 96,485 coulombs. In circuits, the coulomb links to capacitance: one farad stores one coulomb for every volt across the capacitor. Before 2019, the unit hung on the ampere, which was defined by the force between two current-carrying wires.
The name honours the French physicist Charles-Augustin de Coulomb. It arrived late: in 1878 a British scientific body already had official definitions for the volt, ohm and farad, yet none for charge. The International Electrical Congress adopted it in 1881, alongside the volt and ampere. A laboratory-based international coulomb followed in 1908, and when those reproducible units were dropped in 1948, it became the modern coulomb.
Source: Coulomb
