02. Basic Concepts and Illustration

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AC vs. DC charging – what's the difference?

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  • AC (alternating current): this is the “normal” charging used at home and at most public locations. The car's own charging electronics (on-board charger) convert the current, so the speed is determined jointly by the car and the wall charger (e.g. 7.4 kW single-phase, 11 kW three-phase).
  • DC (direct current): “flash charging,” where the charger feeds current directly into the battery at high power (50–350 kW). Faster, more expensive, and puts more strain on the battery.

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What does kW mean? Give an everyday example!

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[answer]

kW is a unit of power. A kettle or hair dryer is about 2 kW. An 11 kW wall charger is like running five kettles at once — for hours. That's why a dedicated circuit and proper protection are needed.

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[question]

How do I estimate the charging time?

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Roughly: battery capacity (kWh) ÷ charger power (kW).
Example: 60 kWh battery ÷ 11 kW ≈ ~5.5 hours (ideal case, without losses).

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