When you charge at home, some of the electricity you pay for never reaches the battery: usually 5% to 15% on a wallbox, and up to a quarter on a 3-pin plug.
At a rapid charger, less is lost after the meter, because the charger changes the electricity before it's measured. That loss is built into the price per kWh instead.
In tests by the ADAC, Germany's biggest motoring club, five current cars lost 12.7–24.2% on a 3-pin plug and 5.1–7.0% on a three-phase wallbox at full power. Most UK homes have a single-phase supply, where cars from 2017 to 2022 lost 11–14% in their own charger alone (Technical University of Denmark).
When it works out the cost per mile, Fuelripper allows for 12% of the electricity you pay for being lost when you charge at home or at a public charger under 50 kW, and 5% at rapid chargers.
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