Bidirectional Charging
Bidirectional charging allows electrical energy to move both into an electric vehicle battery and back out through compatible equipment. It describes a charging-system capability, not one specific destination or service for the exported energy.
What it includes
During ordinary charging, power flows from a building or charging point into the vehicle. A bidirectional system can reverse that flow when the vehicle, EVSE, power electronics, communication, installation, and control software all support it.
The destination determines the use case. Export may supply a portable load, a home, a commercial building, another vehicle, or the electricity grid. These are commonly described as V2L, V2H, V2B, V2V, and V2G. Support for one does not prove support for the others.
Important boundary
A vehicle advertised as bidirectional is not automatically ready for vehicle-to-grid service. Grid-connected export can require compatible EVSE, electrical protection, an approved interconnection, metering, a utility or market program, and permission under local rules. Backup operation can instead isolate a home or building from the grid before the vehicle supplies it.
Bidirectional charging is also different from smart one-way charging. Smart charging can change when or how quickly energy enters the battery without allowing export.
For the system architecture, standards, use cases, and buyer checks, see Bidirectional Charging.