Plug-in Hybrid Electric Vehicles (PHEV): A complete guide

Electric vehicles (EVs) will revolutionise the automotive industry with their unique and innovative technology. But that revolution is at least a few years away from now. Although electric cars are gaining popularity, it’s not everyone’s cup of tea, especially in India. One of the closest alternatives to EVs is the Plug-in Hybrid Electric Vehicles (PHEV). They provide the flexibility of switching between electric mode and conventional engine mode. Read on as we provide you with a complete guide on PHEVs.

What are Plug-in Hybrid Electric Vehicles (PHEV)?

The PHEV full form is Plug-in Hybrid Electric Vehicle. It is a vehicle that uses a combination of an electric powertrain and a conventional Internal Combustion (IC) engine. Unlike a traditional hybrid car, the PHEV comprises a larger battery pack which enables it to run on pure electric power at slower speeds.

One can charge the battery by plugging it into an external power source. The battery also gets charged via regenerative braking or through the IC engine. The IC engine can take over and propel the vehicle during high-speed cruising. In some scenarios, the electric motor can also assist the engine for better efficiency. A PHEV is similar to a standard hybrid vehicle except for the larger battery pack and the capability to run on pure electric power.

PHEV cars in India in 2022

Like electric vehicles, the Plug-in Hybrid Vehicles command a premium price tag. That’s predominantly due to the advanced electric powertrain and a larger battery pack. Hence, you don’t see many manufacturers offering PHEVs in India. Below is the list of the plug-in electric vehicles in India as of April 2022.

*As per ARAI (Automotive Research Association of India)

Best PHEV SUVs

As mentioned earlier, only a few plug-in hybrid cars are on sale in the Indian market. Hence, there are not many options available in the SUV segment. The Volvo XC90 Recharge is the only PHEV SUV available in the country.

Best PHEV sedans

The story is no different when it comes to the sedan segment. Since plug-in hybrid technology is complex and expensive, only a few manufacturers are keen to explore this segment. Currently, the BMW 7 Series is the only PHEV sedan available in India.

Best PHEV hatchbacks

In India, hatchbacks are predominantly mass-market offerings. Even the premium hatchbacks carry an affordable price tag. A plug-in hybrid hatchback may be way too expensive in a price-sensitive market such as India. That’s the reason why there are no PHEV hatchbacks in India.

How does a Plug-in Hybrid Electric Vehicle work?

The overall working principle of PHEV vehicles is similar to standard hybrid cars. The only difference is the larger battery pack which needs to be plugged into an external power source. Refer to the points below to understand how a plug-in hybrid car works.

• Typically, a PHEV starts up in all-electric mode, wherein the electric powertrain independently propels the vehicle.

• The vehicle will continue to run in pure electric mode until the battery pack runs out of charge.

• In some PHEVs, the vehicle switches to hybrid mode (electric motor + IC engine) once the car hits cruising speeds.

• Once the battery charge is depleted, the IC engine takes over, and the vehicle functions as a conventional petrol/diesel car.

• The battery pack can be charged by plugging it into an external power source.

• The battery also gets charged via regenerative braking and with the help of the IC engine.

Also read: How do electric cars work?

Types of PHEVs

Further, there are two types of plug-in hybrid configurations.

• Series plug-in hybrid: In this type of configuration, only the electric powertrain propels the vehicle. The vehicle runs on all-electric mode until the battery charge depletes. Once the battery loses its charge, the engine powers the electric motor. The series plug-in hybrid may not use conventional fuel at low speeds and short commutes.

• Parallel plug-in hybrid: In this type of setup, both the electric powertrain and the conventional engine propel the vehicle in almost all driving conditions. Generally, the vehicle can operate in all-electric mode only at slow speeds.

Key components of PHEV

Below are the key components of a Plug-in Hybrid Electric Vehicle.

• Electric motor: An electric motor is a crucial component of the electric powertrain. It propels the vehicle in pure-electric mode or works in tandem with the IC engine. Depending on the PHEV type, the electric motor draws power from the battery pack or IC engine.

• IC engine: The conventional engine propels the vehicle when the battery runs out of charge. The IC engine may also power the electric motor or charge the battery pack in some vehicles.

• Battery pack: There are mainly two types of batteries in a PHEV. The primary battery pack is the traction battery that powers the electric motor, and the secondary or auxiliary battery powers other electrical components of the car. The traction battery can juice up by connecting it to an external power source.

• Onboard charger: Since the battery needs to be charged, the onboard charger plays a crucial role. It converts the AC (Alternative Current) electricity to DC (Direct Current) electricity to charge the battery pack. It also monitors various parameters such as battery voltage, temperature, charging status, etc.

• Generator: It generates electricity with the help of an IC engine. Some electric motors also act as a generator as they convert kinetic energy (energy loss while slowing down the vehicle) into electrical energy. The electrical power is utilised to charge the battery.

• Transmission: Without a gearbox, the electrical energy and IC engine are of no use; because it is responsible for the transmission of power from the engine/electric motor. A PHEV uses a conventional transmission like any other petrol/diesel car.

• Charging port: It allows the battery pack to connect to an external power source via a cable. The charging cable connects to the charging port and a power source such as the standard household socket or a dedicated charging station.

• Fuel tank: It holds the fuel for the Internal Combustion engine. When the battery runs out of juice, the IC engine takes over, and the engine can only run if there’s fuel. Hence, it’s also a crucial component of a plug-in hybrid car.

PHEV: Pros and cons

You already know what a PHEV is and how it works.  Now, let’s look at the advantages and disadvantages of plug-in hybrid vehicles.

Advantages of Plug-in Hybrid Electric Vehicles

Below are some of the pros of PHEVs.

• PHEVs produce zero emissions when running on pure electric mode.

• They produce fewer carbon emissions compared to conventional petrol/diesel cars.

• The plug-in hybrid cars are fuel-efficient at slow speeds, with the electric powertrain assisting the engine.

• The running cost is low if you drive for short distances.

• No range anxiety as you can rely on the IC engine for longer journeys.

Disadvantages of Plug-in Hybrid Electric Vehicles

Here are some of the cons of plug-in hybrid electric cars.

• PHEVs are expensive compared to their conventional and standard hybrid counterparts.

• The fuel efficiency may more or less be the same as a conventional vehicle during long highway journeys.

• The pure electric performance may take a hit with the deteriorating battery life.

• The battery charging takes a few hours, depending on the type of charger.

• The repair costs of the electric powertrain may run high.

How to charge a plug-in hybrid car?

PHEV charging is similar to charging an electric vehicle. You need to connect the charging cable to a power source and plug in the connector to the onboard charging connector. If you charge your plug-in hybrid car via a standard home power outlet, you can follow the steps below.

• Step 1: Connect the charging cable to a power outlet. Typically a 3-pin plug slots into the household power socket.

• Step 2: Locate the charging port in your vehicle and ensure that it is accessible.

• Step 3: Connect the connector plug to the charging port.

That’s it; your PHEV will start charging.

If you have set up a home charging station, all you need to do is slot the charging connector into the charging port on the vehicle, and the battery will start charging.

Lastly, you can also charge your PHEV at a public charging station. However, ensure that the charging plug or the connector is compatible with your vehicle. You can drive your car to a public charging station, connect the plug to the charging connector slot, and the battery will start charging. Once done, you can make the payment for the consumed electricity.

Also, read: Charging an electric car at home: Time, cost, set up and more

Difference between PHEV and BEV (Battery Electric Vehicles)

Refer to the table below to know more about PHEV vs BEV. We have compared both vehicles based on various parameters to highlight the key differences between pure electric and plug-in hybrid cars.

Difference between PHEV and HEV 

Refer to the table below to get a better understanding of PHEV vs HEV (Hybrid Electric Vehicle).

Upcoming plug-in hybrid cars in India

As mentioned in the previous sections of this article, PHEV is a very niche segment in the Indian automotive market. There are only a few cars on sale in India. Moreover, the major car manufacturers are focusing on EVs rather than PHEVs. Hence, there is no concrete information regarding upcoming PHEVs in India. However, expect Volvo, BMW, Toyota or Hyundai to explore the plug-in hybrid segment in the country.

How do PHEVs impact the environment?

One of the significant benefits of PHEVs is the lower carbon emissions. Since vehicular emissions are the major contributor to the increasing pollution, plug-in hybrids have a substantial impact on reducing vehicular pollution. With bigger battery packs, PHEVs are capable of operating in pure electric mode with zero emissions. And in hybrid mode, the vehicles produce significantly less carbon emissions. Overall, PHEVs are the next best alternative to EVs when it comes to reducing vehicle emissions.

Frequently Asked Questions (FAQs)

Let’s look at some of the most frequently asked questions and their answers regarding PHEV cars in India.

Is a plug-in hybrid car as reliable as any other petrol or diesel car?

Yes, plug-in hybrid cars are reliable since they have an electric motor and an IC engine. If the battery runs out of juice, the engine will take over. Hence, you need not worry about getting stuck due to battery issues or electric powertrain problems.

What happens if I don’t charge my plug-in hybrid car?

If you do not charge a plug-in hybrid car, it will start with the help of the IC engine and will function as a normal hybrid car. That means the electric motor can only assist the engine since it does not have enough charge to propel the vehicle.

Are PHEVs a better option than pure electric cars?

The answer to this question depends on your requirements. If you are worried about the EV range and charging infrastructure, then PHEVs make for a sensible choice. But if you reside in a metro city with good charging infrastructure, then EVs make for a better option as the long term benefits make up for the high initial investment.

Which PHEV has the longest total range?

The BMW 7 Series PHEV has the longest total range of 1,817 km with an electric-only range of 53 km.

Explore More: 

• Best electric cars in India

• Hydrogen fuel cell electric vehicles in India

• Upcoming electric cars in India