The Combined Charging System (CCS) is a standard for charging electric vehicles. It can use Combo 1 (CCS1) or Combo 2 (CCS2) connectors to provide power at up to 350 kilowatts (kW) . These two connectors are extensions of the IEC 62196 Type 1 and Type 2 connectors, with two additional direct current (DC) contacts to allow high-power DC fast charging. In response to demand for faster charging, 400 kW CCS chargers have been deployed by charging networks and 700 kW CCS chargers have been demonstrated.

Direct current (DC) is one-directional flow of electric charge. An electrochemical cell is a prime example of DC power. Direct current may flow through a conductor such as a wire, but can also flow through semiconductors, insulators, or even through a vacuum as in electron or ion beams. The electric current flows in a constant direction, distinguishing it from alternating current (AC). A term formerly used for this type of current was galvanic current.