The battery system on an electric car can either charge—from regenerative braking or an external power supply—or discharge—powering the EV's motor(s) or supplying that power via so-called vehicle-to-load. As a rule, it can't do both at once, but General Motors has some thoughts about that. The patent analysis site CarMoses spotted a recent GM patent application for a system that is capable of charging and discharging simultaneously. The patent describes a "charging system" with a pair of charging ports.