Electric mobility made simple: A guide to the key terms
Charging a car is essentially like charging a mobile phone, except the cables are thicker and the physics a little more tangible. To help you find your way around, here are the key terms that will turn you into an expert at every charging point.
1. kW vs. kWh: Power vs. Capacity
This is the most fundamental stumbling block. For simplicity, picture a garden hose and a swimming pool:
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kW (Kilowatt): Represents power (the flow of water). It determines how quickly electricity "flows" into your car. The more kW, the sooner you are "fully fuelled".
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kWh (Kilowatt-hour): Represents capacity (the volume of the pool). It is the amount of energy that fits into the battery. If your car has a 60 kWh battery, it tells you how big your "tank" is.
2. AC vs. DC: Where does the current "convert"?
The electrical grid in our homes runs on alternating current (AC), but the batteries in cars require direct current (DC).
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AC charging (Alternating current): The conversion takes place directly in the car (via the so-called on-board charger). It is slower but gentler. Ideal for overnight charging or during work.
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DC charging (Direct current): The conversion takes place in the charging station itself. Energy flows directly into the car's battery at enormous speed. These are the large charging posts on motorways (50 kW to 350 kW).
3. Dynamic Load Balancing (DLB): The guardian of your fuses
This is the "brain" of modern home charging. Imagine you come home, plug your car into the charger, but at the same time you start cooking dinner, switch on the oven, the washing machine and the kettle. Without regulation, you would probably be searching for the fuse box in the dark.
Dynamic Load Balancing (dynamic load management) works as follows:
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An intelligent sensor continuously measures how much electricity your household appliances are currently consuming.
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The home takes priority: If you switch on the cooker, the charger immediately reduces the car's charging power.
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When you finish cooking and switch off the appliances, the charger automatically increases the power back to its maximum.
This means you charge at the maximum possible speed without having to pay for an expensive increase in fuse capacity from your electricity distributor.
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