GM is proud of its . Why shouldn’t it be? The Ultium platform has , while still allowing a to hit 60 miles an hour . But now, it seems, GM wants to add one more trick to its Ultium-branded bag: Dual-port charging.

A , as spotted by , would add a second two-way charging port to the company’s electric vehicles. In its most helpful use case, the second port could allow a vehicle with a dual-layer battery pack (say, a or ) to charge other vehicles or devices through one port, while the second port is plugged into a charging station. From there, however, things get a little more complicated.

The primary charging port, as specified by the patent, supports charging at up to 800 volts — making it compatible with EV chargers. Yet, curiously, when using both ports to charge both levels of the battery pack, each one will only draw 400 volts. Bad news if you were hoping you could charge at 1,600 volts.

If you’re using one of today’s fastest chargers, dual-port charging may not make a difference. But for slower charge points, the difference could be massive. A dual-port vehicle could hypothetically plug into two Level 2 (240 volt) chargers at the same time, essentially charging as fast as a Level 3 charger.

This new patent may not revolutionize high-speed charging, but the two-plug setup could do wonders for those who have to make do with low-speed chargers (provided they’ve got 2 plugs that can reach the car). By accepting the full input voltage of multiple low-speed chargers, owners of GM cars and trucks with two-level batteries could get back on the road twice as quickly — assuming this dual-port technology makes it to production.