ADAC tests smart wall boxes: Good functionality, moderate information

As part of a practical test, the automobile club ADAC investigated whether the supposed overloading of the home power grid caused by multiple charging EVs can be avoided using wall boxes with load management, and came to a positive conclusion. The intelligent wall boxes reliably distributed the available power among several electric cars or paused the charging process until enough power was available again, according to the main findings of the test.

The automobile club examined four systems to represent the variety of solutions offered on the market. The number of maximum possible charging points ranges from six (ABL) to theoretically unlimited (TMH). ABL, KEBA, and Webasto integrate solely wall boxes of the same type, while the system from The Mobility House (TMH) can incorporate wall boxes from various manufacturers into the load management system, the club outlined the test setting. All systems were provided on loan by "The Mobility House."

Reliable function, partly cryptic information

Although the load management systems functioned reliably, the testers see potential for improvement in terms of usability. Information on which vehicle is currently receiving how much power would be helpful for the user. A graphical explanation of the LED charging status display on the wall box is found only at ABL – at KEBA, there are text hints on a display, the club specifies. Otherwise, one has to remember the meaning of various blinking LEDs or – even less practical – have the user manual handy in the parking garage, the criticism states.

In case of charging errors of the car or power failure, the examined systems restarted the charging processes by themselves in most cases after resolving the issue – only with the Webasto system this was not always the case. Considering the costs of wall boxes, manufacturers should also think about theft protection, the club further urges. Only the cheapest product from ABL had a – albeit simple – theft protection. For selecting the appropriate load management system and for installing, configuring, and commissioning the wall boxes, consumers should choose specialized companies with experience in this rather complex topic, the recommendation says.

Creating uniform standards and symbols

The ADAC now sees the manufacturers responsible for making wall boxes as intuitive as possible in configuration and operation. This includes wall box manufacturers agreeing on uniform blinking codes and colors for charging status and error messages. The club also sees car manufacturers as responsible and suggests that they generally display important information during the charging process, such as charging power, battery charge level in percent, and estimated charging duration on the vehicle display.