Convert coulomb to millicoulomb

A coulomb is the charge that one ampere carries in one second, about 6.24 × 10¹⁸ electrons; the practical unit of batteries, the ampere-hour, is 3,600 C, so a 4,000 mAh phone battery stores 14,400 C. The charges of everyday electrostatics are tiny – a crackling jumper or a doorknob shock moves a microcoulomb or less – while a lightning stroke transfers some 15 C, and a 1-farad capacitor holds exactly 1 C per volt.