ADAC tested five EVs for charging losses. One wasted a quarter of the energy

ADAC measured charging losses on five EVs, finding household sockets waste 12.7-24.2% of drawn electricity while an 11 kW wallbox reduces losses to 5.1-7%. The Mercedes CLA lost 24.2% on a socket (dropping to 6.9% with a wallbox) due to its 8-amp on-board charger, and the other models showed similar improvements, saving roughly €76-€231 annually at 37 c/kWh. Fast-charging DC losses range from 5% to 15%, decreasing when the battery is pre-conditioned.