Explaining Electric Cars - Should I Buy an EV and Will It Save Me Money?
Electric cars do make sense - here's all you need to know
There are many reasons to go electric, but it’s not the right choice for everyone. Those covering vast distances each day might want to stick with diesel power, those wishing to tow caravans might be best served by avoiding electric power, and those needing outright performance should stick to a powerful petrol model. For the rest of us, electric power might just make sense, but there’s a lot to understand about it.
What’s a Hybrid, Plug-In or EV?
There’s more to electric than a pure-electric car, with a variety of systems available...
MHEV Mild Hybrid Electric Vehicle: These usually involve a petrol engine combined with a small boost from a tiny battery or capacitor, via a 48-volt electrical system. Efficiency gains come in at around 5-7% over a standard car, at little cost or complexity, which is why you’ll be seeing a lot more cars coming through with this system.
HEV Hybrid Electric Vehicle: The most common type of electrified car, the hybrid was made famous by the Toyota Prius. Sometimes called ‘self-charging’, there’s a petrol engine and an electric motor with a small battery pack under the bodywork, and they combine to share the workload. They never need plugging in, hence the self-charging title, but instead gather energy from braking, coasting and, yes, that petrol engine. They tend to offer efficiency slightly ahead of a similar diesel-powered model, but without the emissions and particulates associated with the fuel.
PHEV Plug-in Hybrid Electric Vehicle: This is a further development of the hybrid powertrain, but includes a far bigger battery. This makes it possible to cover 25-30 miles on electric power alone, making most drivers daily mileage emissions-free. The engine can still kick in to help out, when accelerating hard or climbing a steep hill, for example, but the car tends to favour using the battery power available first. Once the battery has been depleted, the car can continue running on petrol power alone.
EV Electric Vehicle: What everybody thinks of when they think of an electric car. Here there’s no engine, just a battery pack and an electric motor to drive the car. In use, they feel remarkably normal but just much quieter. And, of course, there are zero emissions from the tailpipe. You generally can’t travel as far as you could in a petrol-powered vehicle, which means you’ll need to stop and recharge on long journeys. This can take up to 45 minutes, although you probably won’t need to do that until after two or three hours driving, and you should be taking a break at that point anyway.
What is the range of an EV?
How far you can go in an electric car depends entirely on how big a battery is fitted. The ratio between battery and distance doesn’t vary too much, so any given level of kWh capacity will take you roughly the same distance regardless of the car. Most family cars tend to promise between 200 and 300 miles, with only Tesla breaking the 300-mile barrier for now. You pay handsomely for that extra range, though - a clue that batteries are expensive.
Smaller, city cars, tend to have smaller battery packs, with the Smart fortwo EV able to cover just 99 miles before coming to a halt. However, with the average journey in the UK being less than 10 miles, there’s an argument to be made that ever-increasing range capabilities aren’t necessary, especially as it adds significant cost. The charging network needs to be improved to provide the necessary backup, though.
Plug-in Hybrid vehicles offer an interesting balance, as they’re generally able to cover 25-30 miles on battery power alone, which is enough for most journeys, most of the time. However, once the battery has been depleted, the engine (which is generally a little underpowered) has to drag along the car, battery pack and electric motor, impacting efficiency dramatically.
Hybrid and Mild Hybrid cars aren’t intended to offer a decent range on purely electric power and are often incapable of reaching even a single mile. However, that’s not the point of the technology, which instead focuses on increasing overall efficiency rather by sharing the load between petrol and battery power. Toyota suggests an average journey could see the car running on electricity for as much as 50% of the time, even if you can’t cover much ground in one burst of electric energy.
Charging Types and Times
Charging facilities have been narrowed down to three basic speeds, although there’s still a huge variance within them. However, there’s no need to pay too much attention to speeds, as the car or the charger will limit energy transfer accordingly - that means that plugging a slow charging car into a rapid charger will still see it charging slowly.
Using a Kia e-Niro as a benchmark, the slowest option would be charging it by simply plugging a standard three-pin plug into a wall socket at home. This is likely to provide around 3kW of power, which will provide a charge of 75% of the e-Niro’s capacity in 16 hours.
Most users will opt to have a home charger installed, a dedicated box that allows charging of up to 7kW, cutting that time down to under seven hours. This enables the car to be fully charged while sleeping. Some home chargers can reach speeds of as much as 22kW, but these are rare and expensive, and you’ll need some heavy-duty wiring installed at the house.
Fast chargers run from 7kW to 25kW, although most will be either 7kW or 22kW. Using that e-Niro again, the 22kW option allows for 75% of charge in two and a quarter hours, which should be plenty while out shopping or taking in a show at a theatre. However, most hotel chargers, so-called destination chargers, tend to be at the lower end of the scale, although that’s fine for an overnight stay.
Rapid chargers are generally 43kW or 50kW, and usually (though not exclusively) found at motorway service stations, the latter topping up the Kia’s battery in just under an hour, but tend to be the most expensive way of adding energy to the car.
These times are obviously affected by the size of the battery pack in any given car. The Nissan Leaf’s 40kWh battery pack will take less time to fill up than the Kia’s 64kWh battery but, of course, the Nisan won’t be able to go as far on a full charge.
Connectors and Plugs
There were countless different connectors in the early days of this new generation of electric motoring, but a dominant force is emerging.
Most popular is the Type 2 connector. This uses an alternating current (AC) connector that’s round with a flat top. Inside there are seven pins, able to send electricity through to the car at speeds of up to 50kW. Most charge points are limited to 22kW on this connector, but that will still provide a Kia e-Niro with almost 35% charge in an hour, which is good for about 90 miles.
CCS connectors build on the Type 2 interface with the addition of two extra pins in an extension underneath the plug. These Combined Charging System connectors are used for direct current (DC) charging which allows for speeds of up to 350kW, assuming the car can cope with that level of input. The CCS sockets are also compatible with the slower Type 2 connectors, enabling users to use just one cable rather than carrying around multiple options.
Finally, there’s the less common CHAdeMO, short for Charge de Move. This is a chunkier, round plug socket that contains ten pins allowing for rapid DC charging at up to 400kW. However, there’s no way of charging slowly (something you’ll want to do at home, for example) so cars with CHAdeMO connectors generally also have a Type 2 connector alongside.
Finally, Tesla’s own connector might look like the Type 2 unit, and it is exactly the same size and layout, but the technology behind it is specific to the brand. That means you can’t charge your Kia at a Tesla station, but a Tesla can connect to a Type 2 unit when necessary.
While maximum charging speeds with all these technologies are impressive, the UK charging network is generally limited to 50kW currently, with only 11 charge stations offering 100kW or more. Tesla’s 120kW Superchargers are available across the country.
What is a Watt, kW or kWh?
Think back to your physics lessons at school and you’ll remember that a kilowatt, or kW, is a unit of power, and it’s how it’s being used that really matters. Charging units measure their output in kW, the higher the number the faster the machine pumps energy into your car.
The same is true in reverse, with how quickly a car is using that energy also measured in kW. The harder you drive, the sportier the acceleration, the more kW of energy you’ll be using.
The kWh measure tries to explain how quickly you’ll use the available energy in a battery pack. It stands for kilowatt-hour and explains how many hours it can provide a kilowatt of power for. The Kia e-Niro’s 64kWh battery, for example, shows that it can store enough energy to provide 1kW for 64 hours. The maths work as you’d expect too, so it could also provide 2kW for 32 hours, or 64kW for just one hour.
Will an Electric Car Save Me Money?
In terms of pure running costs, absolutely. Even using the most expensive motorway-based rapid chargers, an electric car driver will be spending around 7.5p per mile. Even a particularly frugal diesel car can’t match that, with a Volkswagen Golf GTD costing just over 10p per mile.
Charging at home reduces those costs significantly. The average cost for a single kWh of electricity is 15.5p, which means it costs just £10 to ‘fill’ a Kia e-Niro’s battery. As that 64kWh battery pack is good for an official 282 miles, that works out at just 3.5p per mile. London to Birmingham will cost just £4.13 in the Kia, against £12.13 in the Golf.
Maintenance costs tend to be lower too, as the motor in an electric car has far fewer parts than an engine, with no timing belts, valves or spark plugs to worry about. The gearbox is simpler too, as there’s usually just a single-speed gearbox, and brakes wear very slowly thanks to the braking offered by the motor. Of course, there’s still climate control system, lights, infotainment, and all the other luxuries we expect these days, but overall costs should show a significant saving.
However, all this needs to be balanced by the higher purchase costs. Electric cars are still more expensive than an equivalent petrol or diesel model, although the gap is closing, and depreciation tends to be higher as buyers are concerned by batteries that may have degraded. This means that monthly payments also tend to be higher on PCP deals, although leasing deals are very competitive as the cars will reach the end of their term well before any battery issues rear their heads.
It’s also worth noting that while taxation for both private and company car drivers is low now, it might not remain that way in the long term.
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