VW’s New Bi-Directional DC Charging Station

Volkswagen unveiled today a new 22 kW bi-directional DC charging station for electric vehicles called the DC Wallbox. The bi-directional device could enable vehicle-to-grid functionality in electric vehicles. It’s a new charging station that aims to close the gap between level 2 charging and level 3 DC fast-charging.

The German automaker described the new device during a press release today: “With the new wallbox, electric vehicles can be charged with direct current (DC) up to 22 kW – which is about double the speed of a typical wallbox working with alternating current (AC). In charging technology based on direct current, the electricity flows directly into the lead traction battery, provided that the electric vehicle features a combined charging system (CCS) charging port. Unlike systems based on alternating current, electric vehicles are charged independently of their integrated on-board chargers that limit charging capacity. Charging the lead traction battery with a direct current, on the other hand, increases the potential charging capacity when compared with alternating current. The charging process can therefore be significantly shortened.”

Electric vehicles can typically be charged with 3 different levels of charging. Level 1, also known as trickle charging, uses a 120-volt regular wall outlet. It definitely is not the best or most common level of charging as it only provides a limited amount and could take days to provide enough charge for a long-range EV. 

A 240-volt outlet provides more power for Level 2 charging which can typically reach around 11 kW depending on the mobile connectors and on-board charger, which converts AC to DC power in order to charge the battery pack.

DC fast-charging or Level 3 uses commercial charging stations which supply power into the battery pack directly. It’s charging rates start at 50 kW and can reach up to 300 kW making it the fast charging solution to date. However, not all EVs are equipped to connect to a commercial charging network.

Although Volkswagen did not elaborate on the use cases of the DC Wallbox, in order to test it, the company is planning on deploying 20 of them at different sites across Germany.

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