Contactor

An electrically operated switch for high currents; in a DC charger it connects the output to the car only after both have checked the connection and matched the voltage.

Explained in

EV charging fundamentals · Stop 04Why doesn't electricity flow immediately?Authorisation is approved, yet the display shows Preparing and power later falls on its own. Safety checks, the handshake and the charging curve explained.

Precharge. The charger matches its output voltage to the battery before the contactors close.

From “What fills those seconds”, stop 04

Also in

  1. Charging hardware · Stop 02Where does AC become DC?Why the charger asks before it switches
  2. Charging hardware · Stop 08Why do chargers fail, and how are they maintained?Five kinds of outage
  3. Charging hardware · Stop 09One charger, fully understoodThe morning in eight moments
  1. BMSBattery management system: the car's electronics that decide how much power the battery accepts at each moment.
  2. Load managementShares a site's grid connection between the cars charging at the same time.