What is a self-charging hybrid?
Find out how self-charging hybrids work and why you might benefit from driving one
The term ‘self-charging hybrid’ is often used in car advertising, particularly from Toyota and Lexus. These brands use the term to differentiate certain models from plug-in hybrids, as a ‘self-charging hybrid’ is simply a different name for a conventional hybrid car.
Let’s look at the differences between a conventional hybrid and a plug-in hybrid. All hybrid cars have three elements: an engine that uses petrol or diesel, a battery, and one or more electric motors. The only difference is that a plug-in hybrid’s battery can be recharged using a plug and an external power source, while a conventional hybrid - or ‘self-charging hybrid’ cannot. These models instead use the petrol or diesel engine to charge the battery, hence why they are called self-charging.
Some confusion might arise around these models because the term hybrid was originally used only to describe cars such as the Toyota Prius and Hyundai Ioniq Hybrid that didn’t have plug-in capability. This meant that when plug-in cars did arrive, there was suddenly a different type of hybrid around and new terms were needed to differentiate them.
Conventional hybrids, or self-charging hybrids, don’t just use the engine to recharge the battery - they also take energy recouped from the wheels when you brake to slow down. However, since they still require petrol or diesel to work, some have criticised the term ‘self-charging’ as misleading.
However, since both types of hybrid car can drive without using the engine at all for short periods - improving air quality and driving comfort for people outside and inside the cars - they’re cleaner than a normal petrol or diesel car, especially in cities. However, conventional hybrids tend to have much smaller batteries, so the engine will need to come on to charge them back up after a shorter time.
One of the reasons that Toyota has started to call its products 'self-charging hybrids' is to appeal to those who want a more efficient hybrid car but don't have the means to plug in and charge up at home. For those people, a traditional hybrid is an excellent choice.
Toyota has been a major player in bringing self-charging hybrid technology to the mainstream, with its flagship hybrid model being the Toyota Prius. The Japanese manufacturer has sold more than 10 million hybrid vehicles, introducing the technology across most of its model range, from the Yaris supermini to the RAV4 SUV.
Read on below to find out more about how hybrid cars work in detail and find out whether choosing one as your next new car could save you money.
How does a hybrid work?
Most full hybrid (or self-charging hybrid) cars feature an internal-combustion engine, an electric motor and a small battery pack. As you drive along, some power from the engine and the kinetic energy recuperated from regenerative braking and coasting is used to charge the battery pack – this is what leads some manufacturers to use the term 'self-charging'. Then, as you accelerate, electricity from the batteries powers the electric motor and helps the car gain speed, making the petrol engine’s job easier and improving fuel economy.
When enough charge is in the battery pack, most self-charging hybrid vehicles can also pull away just using electricity and travel for a short distance at low speeds, using no fuel at all. This is most beneficial in traffic jams, car parks and town centres where there’s a great deal of air pollution.
Some hybrid vehicles, such as the Toyota Prius, allow you to choose how much energy you put into the batteries when you release the accelerator. If you choose a higher level, you can learn to allow the recuperation of energy to slow you down, putting more charge into the battery pack and reducing wear and tear on the brakes. Several Toyota models also feature a fully electric mode, with the brand claiming the latest Yaris Hybrid can manage around 70% of journeys in-town in this setting, using only electric power. Of course, you’ll still need to use the brake pedal to come to a halt or to brake suddenly or in an emergency.
What are the pros of driving a hybrid car?
If you drive a hybrid in built-up areas, with lots of traffic, the technology can keep your petrol or diesel engine switched off for a high proportion of your journey, reducing fuel costs and cutting air pollution.
For this reason, hybrid models tend to emit less CO2 than conventional models, which qualifies them for several incentives. For a start, the Benefit-in-Kind (BiK) bands used to calculate company-car tax are based on CO2, so hybrid cars tend to be somewhat affordable for business users to drive, with most getting a mid-range BiK rating.
As hybrid technology has become more mainstream, the vehicles have also become more affordable, costing a similar amount to an equivalent diesel. Hybrid powertrains are also offered in a wider variety of cars now than ever before, from superminis to luxury SUVs including the Honda Jazz or Renault Clio E-Tech, and the Range Rover Sport Hybrid.
Almost all hybrid cars have an automatic gearbox and are designed to be very quiet and smooth to drive, so they're typically relaxing and easy to master. When sitting in congested traffic, light controls and the lack of a clutch can help reduce fatigue.
Hybrids also require very few changes to your driving habits, because they can be parked anywhere (you don’t need to find a charging point), refuelled at any petrol station and require the same level of care and maintenance as any ordinary car. A major hurdle for electric vehicles has been ‘range anxiety’, with early models often having a range of less than 100 miles and the need to find a working charging point to top up the batteries. A hybrid doesn’t need to be charged and can drive for hundreds of miles on a tank of fuel.
What are the cons of driving a hybrid car?
Once the traffic clears and you head out of town on faster roads, or on the motorway, hybrid cars rely on their petrol or diesel engines to sustain higher speeds. Because of this, hybrids lose their economical advantage in these conditions and will often use slightly more fuel than a modern diesel car.
Because of the small capacity of the battery packs fitted to a self-charging hybrid vehicle, they can’t travel very far, or for very long, on electric power alone – typically less than a mile. If you want to travel for a greater proportion of the time using just electricity, a plug-in hybrid model is more suitable, as most of these can be driven for 20-30 miles without the conventional engine kicking in. To achieve this, plug-in hybrids require a much larger battery pack that requires charging from a mains supply or public charging point, but they're also significantly more expensive to buy as a result.
Lastly, driving a hybrid car may not suit all drivers, particularly enthusiasts. With an automatic gearbox, engine and even eco tyres all designed to reduce fuel consumption, hybrid models aren’t going to appeal to devotees of hot hatchbacks or sports cars. However, times are changing, and hybrids are becoming far better to drive and much faster. A world where sports cars and even supercars are fitted with hybrid technology is already here, and we've ranked the best hybrid and electric sports cars here.
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