Future Stellantis EVs might flex 800V at 400V Superchargers

• Patent enables higher charge rates from lower-voltage DC fast chargers
• Solution adds a series of relay switches and a capacitor
• It’s a sensible workaround for Tesla V3 Superchargers, which may’t charge at 800 volts

Stellantis is working on hardware to spice up the output of low-power DC fast-chargers for electric vehicles that may handle that extra power, while keeping added weight and complexity to a minimum.

Between the lines, although the patent makes no mention of Tesla, it could make a serious real-world charging difference. The thought might allow 800-volt EVs—large EVs just like the upcoming Ram 1500 REV—to charge at the next rate when plugged into sub-800-volt fast-charge connectors, equivalent to the overwhelming majority of those on the Tesla Supercharger network.

Stellantis confirmed plans to adopt the Tesla-based charge port, otherwise called NACS and now a part of a normal called SAE J3400, in February.

This proposed boost system is described by the automaker in a patent filing published by america Patent and Trademark Office (USPTO) Oct. 31, 2024, but originally filed Apr. 25, 2023. In it, Stellantis says the system is designed to take full advantage of the charging capabilities of 800-volt vehicle electrical architectures even when charging at 400-volt DC fast-charging stations.

Stellantis DC fast-charging boost system patent image

While dedicated DC boost modules exist, these add significant cost and weight, and could be difficult to package, Stellantis says within the document. As a substitute, the automaker proposes using a series of relay switches to spice up voltage. These switches, together with a small DC capacitor, can be the one additional components needed, in line with Stellantis, which added that such hardware might be applied to plug-in hybrids in addition to EVs.

When charging at a lower-power station, the relay switches would allow current to flow through a vehicle’s inverter and an electrical motor during charging, with those components generating two AC phase currents that might be converted right into a third, higher-power DC current that may then be fed into the battery.

Stellantis DC fast-charging boost system patent image

The feature may not immediately be relevant for all that many models. Stellantis is sticking with a 400-volt architecture for a lot of the near-term EVs built on its STLA platform strategy set to underpin the 2024 Dodge Charger Daytona and 2024 Jeep Wagoneer S. Nevertheless it has confirmed those big Ram EVs will charge at 800 volts.

Streamlining charging hardware has been a significant focus for Stellantis. In 2023 the automaker discussed plans to drop onboard chargers and inverters altogether in a bid to simplify future EVs.