Do you need to charge a hybrid car?

To charge or not to charge, that is the question. Happily, we have the answer for all the different types of hybrid cars…

James Wilson
Jun 6, 2022

With all the fanfare surrounding mild hybrid, hybrid, plug-in hybrid and electric cars, it can be very difficult to suss out all the differences. Knowing which of these can be charged and which must be charged, is one of the most important things to get to grips with.

Car makers don’t exactly help the situation with their countless ways of describing hybrid vehicles. For example, traditional hybrids are sometimes referred to as HEVs (hybrid electric vehicles), while mild hybrids share 'hybrid' in the name but are a very different type of car.

Likewise, the term ‘self-charging’ is used by some brands. On the face of things, this sounds like a car that can create energy from nothing but the truth isn’t as impressive. Self-charging hybrids are still great cars for some types of drivers, though. We’ll look at them in more depth later on.

For simplicity, it is best to break hybrids down into three distinct types. There are mild hybrids, hybrids and plug-in hybrids. One thing to remember about all models is that, as long as there is petrol or diesel in the tank (which specific fuel depends on the exact model), a flat battery will not leave you stranded as these cars can simply use their conventional engines, with little or no electric assistance.

This is a major difference to fully electric cars, which require charge in the battery to keep moving. Do bear in mind, however, that electric cars have much larger battery packs than hybrids, so their electric range is much higher than plug-in hybrid, hybrid and mild hybrid equivalents. Also, while plug-in hybrid models can run absolutely fine with a flat battery, they are highly inefficient if you do this, as you're lugging the additional weight of the electric motor and battery pack around, with little electric assistance.

Mild hybrids

These have the smallest amount of battery assistance. Often they combine a traditional car battery with another larger one that powers a small electric motor which assists the engine for short periods - such as when setting off - rather than allowing for mile after mile of battery-powered driving.

Being the simplest type of hybrid, mild hybrids are normally the most affordable, although some very expensive performance cars use this kind of setup to provide slightly greater fuel economy. Examples of mild hybrids include the compact and funky Suzuki Ignis and the rapid, upmarket BMW M340i.

Do you need to charge a mild hybrid?

Mild hybrids cannot be manually charged. Mild hybrid tech can be thought of as a self-contained system, which manages charging using software and microchips. Mild hybrids are engineered to use battery charge when it will have the biggest benefit to fuel economy or in some cases acceleration, and recharge when this will have the least impact on either of these.

Importantly, as mild hybrid systems can only assist an engine, without petrol or diesel, a mild hybrid is going nowhere. It's best to think of these as conventional petrol or diesel models with a small amount of electric assistance for boosting fuel economy.

There are two ways in which a mild hybrid battery pack is charged. The first is through regenerative braking. This is where the electric motor effectively works in reverse when the driver brakes, slowing the car down and putting a little charge back into the battery pack. The second is when the engine is used as a generator to send charge back into the battery pack.

Hybrids

If a car is simply called a ‘hybrid’, more often than not it will be a ‘conventional’ or ‘traditional’ hybrid. These have more electronics than mild hybrids and can even power the car using electrons alone for short distances at lower speeds. Hybrids can be especially economical in towns and cities - it is for this reason taxi drivers like them.

The batteries these use are much bigger than those in mild hybrids and will normally be sited underneath the car. There will also be at least one electric motor that can assist the engine or work independently to turn the wheels. The original Toyota Prius is one of the most famous hybrid cars, but in recent years other models including the Hyundai Ioniq, Kia Niro and Toyota Yaris have all found popularity.

Do you need to charge a hybrid?

Just like with mild hybrids, you do not need to do anything other than drive to replenish the battery of a traditional hybrid. This is because charge can only be added through regenerative braking and using the engine as a generator.

Thanks to the size of the battery packs used in traditional hybrids, these take longer to charge, but likewise, they last longer, providing a greater amount of electric assistance. Therefore, you can expect a hybrid to be more economical than an equivalent mild hybrid.

Plug-in hybrids

This type of hybrid is often referred to as a PHEV (which stands for 'plug-in hybrid electric vehicle'). PHEVs are as close as hybrid cars get to being fully electric. Depending on the make and model PHEVs can typically travel somewhere between 25 and 45 miles using the battery alone - provided you've fully charged the batteries beforehand.

PHEVs make the most sense when charged regularly, as this ensures the greatest fuel economy and lowest emissions. Fail to charge a PHEV and you might as well go for a cheaper hybrid car, as you'll likely be paying more and getting very little benefit from the larger battery pack, but have heavier batteries to lug around, which will reduce the car's efficiency.

Some of the best PHEVs can reach motorway speeds without needing the engine to assist - handy if you regularly have shorter trips that include 70mph roads. To achieve a longer range and better performance, PHEVs have relatively large batteries and more powerful electric motors than the other types of hybrids. 

Plug-in hybrid cars are becoming increasingly popular, which is why all manner of car manufacturers make them. At one end of the scale there is the relatively affordable Renault Captur and at the other end the decidedly less affordable Range Rover Sport.

Do you need to charge a plug-in hybrid?

Yes, but also no. If you want to take advantage of the potential fuel bill savings and reduce your car's emissions, then you absolutely need to charge a plug-in hybrid. And charge it regularly at that. PHEVs should come with a charging cable which you can plug into the mains but using a compatible charging point is also an option.

Thanks to PHEVs having smaller batteries than fully electric cars, completely charging is quite quick even with slower chargers (which are typically rated at up to 7kW). This is good news for anyone who does not have access to a fast-charging method at home as it means they won’t miss out on electric range due to a lack of time to charge.

Batteries can also be charged using the engine, but this is much less efficient than plugging in and will burn more fuel. Regenerative braking is useful for topping up the battery as well, though this has less impact than simply plugging the car in.

In theory, a driver could never charge a PHEV and it would get them from A to B just fine. In that scenario, though, it would be a complete waste of time and money driving a plug-in hybrid. This is because the batteries and electric motor are heavy, so carting them around everywhere is like lugging around a large block of cement. As a result, more fuel will be used compared to not only mild and traditional hybrids but potentially also regular petrol and diesel cars.

If you're concerned about your environmental impact, it's worth remembering that plug-in hybrids require all the materials needed in a typical petrol or diesel car, plus many of those in electric cars, too - such as those in the battery packs and electric motors. This means they have a large ecological impact and if you're not going to charge the car, it makes more sense to get a hybrid model.

 

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