One of the reasons General Motors designed the batteries for its latest EVs as double-layer packs (that can be switched from being connected in series to parallel) may have been to charge both halves at the same time from two separate chargers. Such a battery pack is already in use in the GMC Hummer EV, but similar ones will also power the upcoming GMC Sierra EV and Chevrolet Silverado EV.
The automotive giant recently applied for a patent on dual charging ports for its EVs. But aside from charging the two sides of the pack independently, and thus theoretically cutting charge times significantly, GM also presents additional use cases for the dual ports, like charging another EV while the one with the twin port is itself being juiced up - this would be useful when there’s only one charger, and the GM EV would provide a port for the other electric car to draw from.
Multiple other situations were also mentioned, like having one port charge the battery pack, while the other would power tools and equipment that you could plug into the vehicle. Based on what we gather reading the patent application, it sounds like GM is looking to make one port fast charging-capable, at up to 350 kW, while the other will just charge the vehicle at slower rates of up to 22 kW.
This would not be something out of the ordinary, though, since there’s already a vehicle in production today, the Porsche Taycan, which has two charging ports of which only one is fast charging-enabled. GM’s patent application does say that for its twin port solution, you would be able to pay to have the second port upgraded to 800 volts, presumably in order to charge both sides of the pack at rapid rates.
What sets this dual port solution apart from the one used in the Taycan is that unlike on the Porsche, which has the ports one on each side, the GM approach is to have them on the same side, one next to the other. This stems from the fact that in the Taycan they were not designed to be used at the same time.
Source: USPTO via Green Car Reports