Today, a charger is a full-fledged computer with more processing power than the Apollo 11 spacecraft that brought humans to the Moon. Before the charging adapter starts pumping the voltage, it must first communicate with the smartphone. Incompatibility of the communication software protocol is the reason why a smartphone with USB PD, for example, cannot fast charge from a VOOC charger.

Read on technical details of fast charging technologies. Find out why the best charger – is your old feature phone's charger.