BPT Channel (Unified vs Separated)
ISO 15118-20 parameter that describes whether bidirectional energy flow uses one shared channel (Unified) or two dedicated channels (Separated) for opposite directions.
Technical Details
Unified typically measures both directions on one metering path; Separated uses two metering paths and switching hardware (dual channel). When switching between charging and discharging in Separated setups, ISO 15118-20 requires explicit 0 kW steps and the EVSE applies 0 kW until contactors are ready for the new phase.
Fleet Applications
Helps fleet operators and integrators understand retrofit feasibility, metering implications, and transition behavior when enabling V2G at depots.
Related Terms
ISO 15118 (Plug & Charge)
Family of standards for high-level communication between an electric vehicle (EV) and a charging station (EVSE), enabling certificate-based "Plug & Charge" and advanced charging control (including bidirectional charging in newer editions).
Bidirectional Power Transfer (BPT)
ISO 15118 concept for charging and discharging where an EV and EVSE coordinate power flow in both directions (V2G/V2B), not just charging.
Bidirectional Charging
Charging that allows energy to flow both into the vehicle and back out to a building or the grid.