Plug-in hybrid vehicle energy flow
Vehicle Stop

The mode means the vehicle is stopped. (There is no energy flow.)
EV Propulsion

Electric power is used to move the vehicle.
(Battery → Wheel)
Power Assist

Electric and Engine power are used to move the vehicle.
(Battery & Engine → Wheel)
Engine Only Propulsion

Engine power is used to move the vehicle.
(Engine → Wheel)
Engine Generation

Vehicle is stopped with the Engine charging the hybrid battery.
(Engine → Battery)
Regeneration

Hybrid battery is being charged by regenerative braking.
(Wheel → Battery)
Engine Brake

The vehicle is being slowed down by engine compression.
(Wheel → Engine)
Power Reserve

Engine is both driving the vehicle and charging the hybrid battery.
(Engine → Wheel & Battery)
Engine Generation/Motor Drive

The vehicle is being slowed down by engine compression and regenerative braking. The hybrid battery is being charged by regenerative braking.
(Engine → Battery → Wheel)
Engine Generation/Regeneration

The engine and regenerative braking system charge the hybrid battery driving deceleration.
(Engine & Wheel → Battery)
Engine Brake/Regeneration

The engine compression can be used to slow the vehicle. The regenerative braking system can be used to charge the hybrid system.
(Wheel → Engine & Battery)