power drop through household sockets?

power drop through household sockets?

In its latest study, ADAC shows that wall sockets cause significant losses in cars when recharging.

In its latest study, ADAC, the German automotive association, shows that electric vehicles lose a large amount of energy when recharging. An interesting discoverywhile these losses sometimes cost the driver a lot, without the latter realizing it.

Charging electricity, local stores showed

To carry out this research, ADAC tested for payment on four different types. The association compared charging in an indoor socket (alternating current) and in a Wallbox type wall outlet. Selected examples are the following: Renault Zoé, Fiat 500e, Volkswagen ID.3 and Tesla Model 3. The results are as follows.



Wall box


A recessed wall box


Renault Zoe

2.3kW / 24.2%

11kW / 9.7%

there is no measure


2.3kW / 13.6%

11kW / 9.0%

5.5kW / 9.2%

Tesla model 3

2.3kW / 15.2%

11kW / 7.7%

3.5kW / 11.4%

Fiat 500e

2.3kW / 12.7%

11kW / 6.3%

3.6kW / 13.9%

Source: ADAC

Based on the data obtained by ADAC, we see that the losses are sometimes significant. So, in a typical household socket, the observed loss during recharging on the Renault Zoé is 24%. We note that losses are also high in Wall Boxes, and sometimes around 10% of energy is lost during recharging. Losses that have costs, since this it can cost up to €120 per year for the Renault Zoé model.

How can these losses be explained?

If household sockets lose a lot of energy during recharging, it is due to the nature of the current. Indeed, electric vehicle batteries cannot just save the live stream. However, the home network only provides alternating current. Therefore, the on-board charger must itself convert alternating current to direct current, which describes great loss.

The study also shows that other losses occur within the vehicle’s electrical system. Not least because of the different control units, which work during recharging. These consume a lot of energy.

Finally, ADAC notes that a charging cable that is too long, or aging or faulty equipment may cause additional energy loss.

Read also:
The new Citroen C5 X plug-in hybrid in front of our readers
NEXSD One: an innovative motorhome model
Green insurance sticker: the end sooner than expected?

How to avoid these losses?

To avoid these disadvantages, ADAC recommends “always charge in a wall box with the highest charging capacity”. Therefore, the battery should be charged as soon as possible, because the higher the power, the shorter the charging process.

ADAC also provides three measures that producers must put in place to reduce these losses:

  • Manufacturers should make the resulting load losses transparent so that electric vehicle users can act accordingly.

  • The efficiency of on-board chargers needs to be improved. AC charging mirrors most of the charging processes, so it’s more likely to save energy.

  • The onboard 12 volt system should be turned down to minimum during the charging period.

Source: ADAC