A full hybrid electric vehicle or FHEV for short, is a type of hybrid vehicle that combines an internal combustion engine (ICE) with an electric motor and a battery pack. The combustion engine in an FHEV typically runs on petrol or diesel, while the electric motor is powered by a battery pack. The battery pack, typically smaller than on plug-in hybrids, is charged regeneratively.
How Does It Work?
Full hybrid electric vehicles can operate on the internal combustion engine, the electric motor, or a combination of both. The hybrid system finds the right balance and switches automatically between petrol and electric power, using each power source as efficiently as possible based on the driving conditions and power demands.
The FHEV’s electric motor assists the combustion engine by providing additional power during acceleration and low-speed driving. By doing so, it reduces the load on the ICE, improving overall efficiency. In relation to this, it means that when driving on a motorway at a constant high speed, the electric motor’s contribution would be minimal.
The electric motor is often used on occasions when the petrol engine is least efficient, e.g., when the vehicle is setting off. But also during low-speed driving and in other such situations. This includes urban environments with frequent stops and starts, where the electric motor’s instant torque can have a big impact on fuel efficiency.
The ICE in FHEVs typically kicks in when additional power is needed, such as during high-speed driving, passing other vehicles, and uphill climbs. That is, in those situations where more torque is required. Should the vehicle be driven solely using the ICE, the fuel efficiency would be lower compared to using the hybrid system as intended.
By combining the combustion engine and electric motor, hybrids offer improved fuel efficiency and reduced emissions compared to conventional internal combustion engine vehicles.
No External Charging
Unlike plug-in hybrids, full hybrids do not need to be charged from an external power source. Instead, FHEVs utilise regenerative braking, a process that captures and converts kinetic energy. The electric motor functions as a generator, converting kinetic energy into electrical to charge the hybrid battery. By harnessing the energy generated during deceleration and braking, which would otherwise be lost, FHEVs maximise their efficiency and reduce energy waste.
When the FHEV is running on its internal combustion engine (ICE), a portion of the engine’s power is directed towards charging the hybrid battery. Excess power generated during acceleration and cruising is used to charge the battery instead of solely powering the wheels.
This charging method helps to maintain the state of charge of the battery and ensures it has sufficient energy storage.
Full hybrid electric vehicles are environmentally friendly with low CO2 emissions and improved fuel efficiency. The most obvious drawback is their higher cost. Also, compared to electric vehicles and plug-in hybrids, FHEVs have limited electric-only range.
The benefits and drawbacks can vary depending on specific vehicle models and manufacturers.
Synonym(s):
- Self-charging hybrid
- Full hybrid
- Strong hybrid
- Parallel hybrid
- Hybrid car
- Hybrid electric vehicle
