If you want to charge a plug-in hybrid or fully electric car at home, you can do so in various ways. You can simply charge your car via a charging cable at a conventional socket, but you can also charge a ‘wall box’ go, a socket on the wall with which you can charge your electric car. This not only charges a lot faster, but also prevents a considerable amount of power loss, according to research by Adac.
The Adac investigated how much power was consumed in several electric cars when recharging at the 220/230V connection and at a so-called wallbox. The differences were significant. For example, when recharging with a so-called standard Granny Charger (charging cable of 2.3 kW), there was a power loss of 24.2 percent on a Renault Zoe, while that was only 9.7 percent on a wallbox (11 kW).
When using a wallbox, the charging power is also important: the higher, the better. For example, with a Tesla Model 3 you lose 7.7 percent power if you top up with 11 kW, but 11.4 percent if you charge with a wallbox with 3.5 kW. The advice of the Adac is therefore: charge with the highest possible power to lose less power. Since charging with a low charging capacity takes longer, more power is also lost. That is why charging with the highest possible charging capacity (and therefore also with a wallbox) is the most efficient.
According to the organization, power is lost on the way to the car battery in various ways. With a standard charger up to 4 percent power is lost via cabling before the power reaches the car, with a wallbox this is only less than 1 percent. The on-board charger then consumes another 5 to 10 percent (because of charging management, among other things) regardless of the charging method, and the 12 V systems on board the car can also grab 5 to 15 percent of power for the battery.