TG's big EV glossary: the A to Z of what every electric car term means | Top Gear
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Tuesday 3rd October

TG's big EV glossary: the A to Z of what every electric car term means

WLTP? BEV? mpkWh? Don’t fret, pet – Top Gear is here to clear things up

  • Welcome

    Much like clowns, making sense of electric vehicle terminology can seem daunting, and even downright scary. But, unlike clowns, electric vehicles can actually be really entertaining and are unlikely to emotionally scar your children for life.

    And, because we at Top Gear love nothing more than helping you (and also because our editor made us... hi boss!), we’re going to demystify the serried ranks of acronyms and initialisms and jargon that make the simplest cars on the road the hardest to understand. So, if you’ve ever stared, dumbfounded, as someone talked about how a PHEV blends its ICE and electric motors well, but is let down by a 3.2kWh battery and CHAdeMO plug when it should use a CCS, this is probably for you.

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  • Contents

  • EV


    Let’s start with a simple one. EV just means Electric Vehicle, as opposed to one powered by petrol, diesel, used chip oil, Chanel No.5 or magic.

    This is the broadest genre there is; there are sub-groups within EVs that all approach the same idea from different origins. And we’ve gone ahead and explained all of the damn things, so hold on tight.

    If electricity runs through an electric motor to move – or help move – the car, you’ve got yourself an EV of one description or another. Although anyone with a shred of honesty in their soul would call the hybrids, and especially the mild ones, ‘electrified vehicles’, not ‘electric vehicles’.

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  • BEV


    Welcome to the most pointless of all acronyms. And, what’s worse, it isn’t pronounced ‘Bev’, like the lunch lady that’d sneak you an extra pizza pocket on Fridays, but ‘B-E-V’. So it’s not even an acronym – it’s an initialism. And it stands for Battery Electric Vehicle. As opposed to what... steam-fuelled? Just call them EVs like everyone else does and stop being so damn contrarian. That's our job.

    But if we’re absolutely forced to be pedantic, we’ll admit that there are many cars that you could call electric vehicles – there are hybrids (HEVs, known to Toyota as ‘self-charging hybrids’, like they're perpetual-motion machines), plug-in hybrids (PHEVs), and mild hybrids (MHEVs). But like we said before, it's more ‘electrified vehicle’ than ‘electric vehicle’.

    And, with hydrogen fuel ‘just around the corner’, we’ll have to delineate between electric vehicles powered by batteries – BEVs – and those powered by fuel cells, or FCEVs.

    For right now, at least, the chances are that if you’re driving what you call an electric car – sorry, Electric Vehicle – it’s going to get its energy from an onboard battery.

  • ICE


    The Internal Combustion Engine, or what tends to send the world about the place. There are many types of internal combustion engine – the ubiquitous Otto cycle, or what you’d recognise as a regular engine, dominates personal transport, but look to commercial and military applications and you’ll see the same ‘burn fuel in air, use power generated for movement... somehow’ flow chart in everything from a two-stroke weed whacker to a jet engine.

    For reasons only known to science, ICE can also stand for In-Car Entertainment (i.e. the stereo, touchscreen and so on). But we’ve applied some gentle corporal punishment to the few in the Top Gear office who deigned to use it in this manner and we’re told, when the casts and wires come off, they’ll have at least 70 per cent function in their limbs.

  • HEV


    This stands for Hybrid EV, or what most of us call a hybrid. And a hybrid is the unholy union of two cars, bred together to win the ‘Best new breed’ award at Car Crufts, then beaten out by an Australian Shepherd / Bernese Mountain Dog mix. Because have you SEEN those? A dog so cute it can win anything, including made-up car awards and nine tenths of our hearts forevermore.

    Hybrid really just means the use of both an internal combustion engine and an electric motor. It’s the most common form of electrification and the most likely to be used as a private hire car, at least in London. The streets here are lousy with that most ubiquitous of hybrid cars, the Toyota Prius. But thousands not-actually-employed-by-Uber drivers can’t be wrong about their choice of car, can they?

    Before we wade any further into that particularly goopy quagmire, let’s talk instead about the technology involved in your 3am ride home. Priuses – and a lot of other hybrid cars from manufacturers across the spectrum – use a specific type of petrol engine that’s designed to be more fuel efficient than the regular kind at the expense of torque and power. But that’s OK, because a battery-powered electric motor takes up the slack and combines its outputs with those of the sort-of-anaemic petrol one to deliver decent-enough performance. Not going to pin your ears back, or anything, but that was only really a concern for Wayne Rooney anyways.

    How does the battery get powered up? By generation – either when you're off the throttle entirely and coasting, or when the engine can make more power than the wheels need, and the rest is fed to the battery.

    If this sounds quite complicated, it is. Modifying a petrol engine to use less fuel, then using it to power the car AND as a generator to charge a battery, then using the power in that battery to drive an electric motor to help move the car. Bewildering. Yet such is the inefficiency of a regular petrol engine, this round-the-houses procedure uses less petrol. It’s one of those things that common sense suggests is entirely laughable, but physics – and real-world testing – prove to be entirely accurate.  

    Hybrids used to do exceptionally well on the old NEDC efficiency tests, because they're great when stopped or accelerating slowly. And, because the NEDC was basically that on repeat for a couple of minutes, they’d return unbelievably good test figures. But, as you’ll no doubt know, people can’t accelerate that slowly without falling victim to road rage, so the theoretical advantage evaporates.

    With that said, let’s burst a few petrolhead bubbles right now – hybrids are still more efficient than straight petrols and diesels in real life. In city situations, the electric assistance and reduced idling cuts fuel use and emissions by as much as 40 per cent. These advantages, as you might expect, don’t carry over to the motorway – unless it’s the M4 on bank holiday weekend, where traffic moves like treacle – but hybrids can still return about 20 per cent better fuel economy on the highway. Because we’re not scientists, we got those figures from some concerned ones, who have an organisation named after who they are and how they feel.

  • PHEV


    The Milli Vanilli of electric cars. Yes, there’s a great big song and dance by their manufacturers, but the reality is that when someone says Plug-in Hybrid Electric Vehicle, they’re just talking about a regular hybrid with a bigger battery that you can plug into a wall socket to charge, instead of using the engine or regenerative braking.

    They do amazing mpg figures in the official tests – especially the old NEDC. But in real life... well, just like Milli Vanilli, they have to admit they don’t deserve the plaudits. Sure, if you plug in every night and commute, say, 20 miles, you might not use the engine from one weekend to the next, meaning infinite mpg during the week. Conversely, if you drive one on the motorway without judicious charging overnight, you'll get three fifths of Buckley's improvement over a regular hybrid car.

    And here’s the gap between expectation and reality: the official mpg and CO2 figures depend on people actually plugging them in. Now, tell that to the wily characters who bought PHEVs to cash in on government incentives and didn't bother with the whole 'use the car as it was designed' faff. It worked, at least to begin with, when governments were throwing tax breaks and subsidies at these PHEV fibbers as if doing so would undo centuries of fossil-fuel-fired toxicity in one fell swoop. Cue the sad trombone when the truth about PHEVs began to emerge and the government money started drying up.

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  • MHEV


    If a PHEV is Milli Vanilli, then the mild hybrid EV, or MHEV, is someone who didnt even show up to their first guitar lesson. This, folks, is the very bottom rung of the electrified vehicle ladder. A small electric motor assists the engine, but it doesn't have enough gumption to push the car on its own. MHEVs usually manage a fuel saving of about 10 per cent compared with a pure-petrol car, which feels like the sort of saving you could manage by pulling all the crap out of your boot and being a bit gentler on the throttle. Y’know, rather than mine, refine and install electric battery gubbins at great expense.

    But here we find our old 'friend' – official economy figures, and the tax benefits that come with more efficient cars. We're all for saving petrol (and glaciers and the air and all that good stuff), but this really does feel more than a little disingenuous to call these things hybrids, let alone electric vehicles.

  • REX


    The name Rex comes from the Latin for ‘King’. Something to know if you were picking out dog names. Or trying to remember the first name of that dude from My Fair Lady. In this context, REX – sometimes written as REx – refers not to royalty, or a terrible musical you were forced to watch in high school, but Range Extenders, or small internal combustion engines used as generators to recharge the batteries of an electric vehicle. 

    Now, that sounds a lot like a hybrid car, and it both is and isn’t. Hybrids tend to refer to vehicles that use both petrol (or diesel) power and electricity to contribute to forward motion. In the case of the Range Extender, dino-juice is never put directly to work moving the car around; instead, it’s run at its peak efficiency at all times, converting fuel into electricity, which is then fed to the motors that supply the motive force. So, it’s roughly the same principle as what propels a diesel-electric locomotive, or those massive mining trucks.

    This is why a REx is also called a series hybrid: the engine feeds the battery, which feeds the motor. In series. Prius-type hybrids are called parallel hybrids: both engine and motor can drive the wheels at once, in parallel.

    Cars with range extenders have to lug around the weight of a petrol engine, fuel tank, exhaust pipes and so on. Because of this – and because of the advancement of the energy density of batteries – companies like BMW have generally decided to drop Range Extenders from their electric car offerings.

    Before it was canned, the Chevrolet Volt was king of the range extenders, or, if you will, the Rex of the REXs. Yeah, we know where the door is. We’ll see ourselves out.

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  • Volts, amps and watts

    Volts, amps and watts

    We’re going to go full eighth-grade science teacher on you and use an analogy. Imagine a river: the volts are how fast the river flows, the amps (or amperes, if you’re being fancy) are how much water is flowing, and the watts are how easily it’ll carry you downstream. A small amount of water can move quickly, without shoving much more than a twig, while big, fast-flowing floodwater can pick up buses and carry them... well, like twigs.

    This is also a helpful way to think about electrical safety. Volts hurt – and how – but amps kill. An electric fence will make you jump but the current is low. An electric car battery is a similar voltage but can deliver huge current, which is the deathy bit. It’s also why there are immensely strict safety rules when EVs need to be repaired.

    Multiplying volts by amps gives you watts. Watts is the measure of power. Take your domestic power supply for an example. In most parts of the world, it’s between 220 and 240 volts and 10 amps maximum, so the peak wattage it can deliver is between 2200 and 2400 watts (2.2 to 2.4kW).

  • kW


    Remember when the UK and US were going to change over to the metric system? And remember that alternate reality in which that happened, all without any fuss, and Prime Minister Stephen Hawking joined up with President Nye (the Science Guy) and brought about world peace, cured malaria and set up the 13-month year, so every month would have exactly four weeks and wouldn’t be confusing?

    Yep, much like everything else that’s gone wrong with our country, this one’s our fault. The UK half-heartedly cherry-picked a few metric things and left it at that, which is why you buy your fuel in litres and then get miles per gallon out of it. The US, on the other hand, stuck defiantly to their guns (quelle surprise) and told the metric system not to mess with their freedom. This is also why they still use Fahrenheit, the hieroglyphs of temperature measurement.

    Lovely, logical, metric countries know what a kilowatt (kW) is – they already use it to measure power from petrol and diesel engines. After all horses have always been, and will always be, horrible, stupid animals that are best used for burgers, leather and glue. So, when electric cars came along, with kilowattage, there was no confusion.

    For the rest of us, here’s a little primer – a kilowatt is 1000 watts, and is the most common measure of power in an EV. A kilowatt is equal to about 1.34bhp, and it’s used to measure the same thing: power, or energy transfer per unit of time. So, if a petrol engine – after mechanical and pumping losses, heat soak and other engineering malarkey – makes 134bhp, it’s transferring 100kW of power from the petrol. We should note that really well-done petrol engines run at about 35 per cent efficiency, and new, highly turbocharged diesels can do about 45 per cent. Electric motors transfer energy at 80 to 95 per cent efficiency.

  • kWh


    The keen-eyed among you will spot an addition to the kilowatt (kW) we explained earlier. The bill-payers among you will remember kWh from countless energy bills, in which it came after a few numbers, but – crucially – before the astoundingly large one at the bottom, with a ‘Still to Pay’ next to it.

    It stands for kWh, which means kilowatt hours. Because a watt (and a kilowatt, and even 1.21 gigawatts) are all instantaneous things, the kWh measures work (measured in kilowatts) over time (measured in hours). Science!

    This measurement can cut two ways – it can measure how much power you’ve used (which a utilities bill does), or how much capacity there is in a battery. For instance, a Tesla Model S 100D has 100kWh of capacity, of which you’ll be able to use about 90, because fully depleting a battery is a great way to ruin it forever and generally have a bad day. So, if you hotwired your Tesla to continuously use 900kW, and then somehow didn’t melt the thing around you, you’d have six minutes’ worth of cosmically large power. On the other hand, if you got another, not-melted Tesla, turned everything off, pressed the accelerator like your delicate parts were underneath it and somehow only used 2.5 continuous kilowatts, you could run for 36 of the boringest hours of your life.

    Right, that’s the mildly silly analogies covered. Now, to keep things simple, think of it like this: kilowatts are a measurement of motor power, like bhp in engines, and battery capacity, in kWh, is like fuel-tank capacity in gallons or litres.

  • AC and DC

    AC and DC

    And obvious references to Thunderstruck, right? Wrong. Some jokes are too easy, even for us. AC stands for Alternating Current, and DC stands for Batman comics… er, wait… Direct Current. So, these were two competing standards for the transmission of electric power back in the days of George Westinghouse, Nikola Tesla and Thomas Edison. There’s a fairly boring movie about it, starring Eggs Benedict Cucumberpickle, if you’re looking for more background on that.

    But let’s get down to brass wire connectors: AC is better for long-distance power transmission. This is because Alternating Current can be transformed much more easily than Direct Current. And that’s not the ‘Hey, presto’ kind of transformation – it’s changing the volts and amps while leaving the watts the same. The way to work everything out is that Volts x Amps = Watts.

    So, if you can (and you can, in the case of AC) get the voltage up and keep the watts the same, the amps have to go down. And this is really, really useful when it comes to transmitting that power where it needs to go.

    To send power through a wire isn’t all that hard, but wires do have resistance. Power lost (as heat) in transmission is equal to the square of the current through the wire, multiplied by the resistance of the wire. So, increasing the current makes power loss exponentially worse. But if you reduce the current – while increasing the voltage – you can send power with minimal loss.

    And this, more or less, describes the basic premise of the power grid that goes to your house, office, local shopping centre and roughly everywhere else that needs lights, fridges, computers and anything else powered by electricity. They use high-voltage lines (up to 400kV or 400,000 volts) to distribute the power around the country, and then transform it down in stages to 240V near your home.

    It’s really difficult to transform DC power, and generally involves converting it to alternating current first, then transforming it, then rectifying (converting back to direct current). It’s a complete faff. But, when used locally, DC can be very useful. For instance, most of your complex electrical appliances – computers, TVs, and so on – run on direct current, so they’ll actually have rectifiers, either onboard or in the power supply. You put electricity into a battery by DC. And when a DC rapid charger – be it Tesla, CCS or CHAdeMO – gets involved, you can charge very quickly indeed.

    Electric cars can accept AC charging – plug it into a wall socket, or a dedicated AC charger, and you’re away. But the speed will always be limited by the car – it has to, like all complex electronics, convert the AC into DC before it can feed it to the battery. This isn’t a specific electric car battery thing, by the way – all batteries supply, and are replenished by, direct current.

    And because it’s costly and inefficient to carry a gigantic rectifier (AC to DC converter) onboard, charging generally tops out at between 3kW and 11kW for an EV’s onboard charger. Because DC charging stations can be as big as they need to be, they can employ high-voltage power, giant transformers and rectifiers and get huge power – up to 250kW at the moment, with plans to extend to 350kW in the near future.

  • Slow, fast and rapid – or level 1, level 2, level 3 charging

    Slow, fast and rapid – or level 1, level 2, level 3 charging

    Level 1, level 2, level 3 charging… ah, ah ahhhhh. Look, we’re not entirely sure why the powers that be decided we needed yet more confusing terminology, but here we are. Generally, level 1, level 2 and level 3 are the American terms for what the Brits mostly call slow, fast and rapid charging.

    Level 1 is the easiest level in Super Mario and you should be able to complete it without dying. Also, in the case of charging electric cars, it’s when you use a regular wall plug. Somewhere in the lead between the wall and the car is a smallish box called an electric vehicle supply equipment (EVSE) that contains a couple of bits of circuitry to monitor things and keep them safe. This whole cable/box doodad is commonly called a 'granny lead', officially a level 1 charging cable. It'll get you out of trouble because you can plug in at any house. But not far out of trouble, because it charges so slowly, so most cars don't have one as standard.

    Fast or level 2 refers to the wall-mounted AC charging boxes you can install in your house / office, which still use the car’s onboard rectifier to convert the supply to DC so the battery can charge. They go up to 7.4kW on normal 240V single-phase AC, or 22kW on industrial three-phase.

    Rapid or level 3, on the other hand, is the high-power, DC supply, with the AC supply converted to DC inside the charging station. This is the sort you’ll find at motorway services and dedicated charging areas.

  • Choosing charge speed

    Choosing charge speed

    Right, time to see how that slow, fast and rapid charging works to get the car charged in daily use. For most electric car buyers, the cheapest and easiest way to charge will be at home. But if you’re on longer trips, have no opportunity to charge at home or if those thieving power pixies have spirited away your very last amp and volt, you’ll need to avail yourself of a fast charger.

    Here’s where kilowatts come into play again. Your regular wall socket at home can usually deliver about 2.3kW, so you’ll add (wait for it) 2.3kWh of range to your battery every hour. This is slow or level 1 charging. This also doesn’t sound great – especially if your battery has a capacity of 100kWh, and you’re wondering what 100 divided by 2.3 is so you know when you’ll have a full charge. It’s about 43 hours and 29 minutes, in case you were curious.

    Fast (level 2) home chargers can deliver a much healthier 3.6 or 7kW, which reduces the empty to 100 per cent charge time to 27 hours, 47 minutes, and 14 hours, 17 minutes respectively. You can also find fast chargers in car parks or at the side of residential streets where there are no driveways.

    But you don’t need a full battery any more than you need a full tank of petrol to drive around. If you charge overnight at home on a 7kW fast charge point, you can go from an empty 100kWh battery to more than half full in eight hours, all while buying useless, off-brand crap from Amazon and getting a bit of sleep in front of Netflix while it worriedly asks you if you’re still there. Even chucking it on to charge for an hour at home gives you another 20 miles of range, exactly enough for a trip to work and back for the average UK commuter.

    But, like we said, home charging isn’t always available, or situationally appropriate. While it does make sense to charge at home, it makes less sense to buy a series of houses at 120-mile intervals along the M1 so you can always charge at home. And here’s where rapid chargers come in.

    Out and about, rapid DC chargers are much more potent than anything AC or domestic. Tesla Superchargers can reach 250kW, or enough to fill a 100kWh battery in 24 minutes – theoretically. Porsche has plans to go as far as 350kW soon, which will (very theoretically) brim an empty 100kWh battery in 17 minutes. We’ll need to come up with a new phrase for splash’n’dash... zap’n’zip?

    But, because this is the real world, it’s never as simple as that. You’ll never be truly empty, and battery chargers have to slow down the rate of power transmission as the battery reaches full charge, otherwise there’s a risk of damaging the battery. But, for instance, if you’re at 7.5 per cent charge of a 100kWh battery – the electric version of fumes – and then top up at a 250kW charger for just the 15 minutes it takes to get a sandwich and a coffee, you’ve added 62.5kWh, and gone up to 70 per cent charge, netting yourself another 250-odd miles of range.

    This scenario is an ideal one, but it’s one that’s very likely to become more common as faster chargers spring up. We’ve personally used the 120kW Tesla Supercharger on a Model 3 (out at Membury, if you were curious) and spent somewhere between 30 and 45 minutes sitting down with a sandwich, a coffee and a laptop to type up articles (just like this one) and walked out to find that our Model 3 was basically fully charged. It really does happen faster than you think.

    So, if that’s the ideal (and idealised) scenario, what happens if you didn’t want (or didn’t get) a Tesla? Well, then we have to start talking about CHAdeMO and CCS.

    As of 2020, the maximum charger kW you’ll ever encounter is 250kW for Tesla, 350kW for CCS and 400kW for CHAdeMO. Now, that sounds, and is, incredible. But there are a few issues for the time being – a) they’re still being rolled out, so they’re rare, b) a lot of EVs won’t accept a charge that fast, so you’ll more likely be charging at 50 to 100kW regardless of where you hook up, and c) we’re going to need some pretty substantial work on the power grid before every man and his electric car are dragging hundreds of kilowatts at once. But we figured out space travel, supersonic flight and deep-sea submarines, didn’t we?

  • CHAdeMO


    CHAdeMO is not a droid, nor is it the password to a basement rave in Soho, nor is it the result of a cat walking across a keyboard. It’s basically the fast-charging standard that Japan came up with. Competing standards include CCS and Tesla Superchargers, which all look reaaaaally similar, but work about as well as putting an HD-DVD in your Blu-Ray player. And, as of 2020, it's capable of charging at a faintly terrifying 400kW, in very specific circumstances.

    There are, of course, a few caveats. The first of which is that current CHAdeMO chargers tend to operate at 50kW. This is still quite a bit, all things considered, but it’s not 400. Nor is it the 120kW of a Supercharger, nor the promised 250kW and 350kW from Tesla and Porsche. With that said, CHAdeMO (the company) is rolling out 100, 150 and 200kW chargers as we speak, but there are basically none in Europe. Actually, the only common vehicles in Europe to use CHAdeMO are the Nissan Leaf, NV200 van and Mitsubishi iMiEV. And they have air-cooled batteries that get overheated as soon as charge power goes much beyond 50kW. So a higher-powered CHAdeMO charger is as useful as a chocolate fireguard. And there's more: for its next EV, the Ariya, Nissan will instead use the rival CCS plug, at least in Europe.

  • CCS


    The DC charger you’re most likely to use in the UK and across Europe. And it’ll work in everything from a Tesla to a Volkswagen, but definitely not in CHAdeMO-equipped cars.

    The good news here is that third-party charging companies like Ionity, Ecotricity and so on know that they can double their business by offering CCS and CHAdeMO from one charge point. Check before you go on any number of websites and apps, but the chances are that there’ll be the right plug and charger for you, because they won’t make any money if you can’t use it.

    CCS is already running at 50kW and 100kW in a lot of locations, with an increasing number of 350kW locations starting to crop up as well. Newer EVs, even small ones such as the Peugeot e-208, can accept 100kW for at least part of their charging cycle.

  • Tesla Supercharging

    Tesla Supercharging

    If it looks like a CCS charger and works like a CCS charger... it could very well be a Tesla Supercharger, which you can’t use, unless you drive a Tesla.

    Yep, for the exclusive use of Tesla drivers, the Supercharger is, in TG’s experience, the easiest of all chargers to use. You don't need to swipe a card or register. The charger recognises your individual car and you're automatically billed. Every time we’ve used a supercharger, it’s worked flawlessly and charged in the time it took to water our boots, wash hands and ‘enjoy’ a motorway services sandwich.

    Compare and contrast to connecting to an Ecotricity CCS box, which required a lengthy phone call and the unsolicited ‘help’ of a neckbeard who’d parked next to us. Oh, and we should mention that Ecotricity has a near-monopoly of CCS and CHAdeMo at motorway services in the UK. Then there was the fiasco of trying to fast-charge an I-Pace, which steadfastly refused to take anything faster than the speed you’d get from a wall socket, then set its car alarm off for good measure. We left the damn thing there overnight to trickle charge and went to the pub, if memory serves.

    Another hot tip for prospective Tesla drivers: you can charge via CCS if you’re in a pinch. Any Tesla made before May 2019 will need a retrofit, and the Model S and X will need an adaptor. But, if you’ve got a brand-new Model 3, feel free to hook up when and as you need to. There are also adapters to enable Teslas to take a CHAdeMO charge, which is handy.

    With that said, it’ll probably still be easier to use the Supercharger.

  • Type 1 and Type 2 cables

    Type 1 and Type 2 cables

    For further confusion, while level 1 and level 2 refer to charging power, type 1 and type 2 refer to different plug/socket types on AC leads.

    Type 1 is used by Leafs, plug-in Priuses, Mitsubishi MiEVs and so on. Type 2 is used by most modern EVs, and is becoming the standard, not least because it's compatible with a CCS plug. Type 2 is also known as Mennekes, because that's the company that makes the connector. But isn’t that like calling your petrol Shell, or your vacuum cleaner a Hoover? Oh.

  • mpkWh


    Yeesh... someone get these metric and imperial measurements away from each other before everyone dies of sheer confusion.

    Not content with the unholy union of litres of petrol, pints of milk and, we assume, hundredweights of disdain for anything approaching logic, the UK’s uneasy blend of metric and Rees-Mogg means that we’re left measuring ‘fuel’ economy in Miles Per Kilowatt Hour. So, if you have 50 usable kWh, and run at 4.0mpkWh, you’ll do 200 miles before you’re stranded out in Wicker Man country, trying to charge your car from a farmer’s windmill.

    In Europe, Australia, New Zealand and other tourist destinations, economy is measured in litres of fuel per 100 kilometres. So, for EV’s electricity consumption, it's kWh/100km. Oh metric, you simple, logical and elusive mistress.

  • WLTP


    No, no-one’s mis-spelled ‘Would Like to Meet’. This snappy initialism stands for ‘Worldwide Harmonised Light Vehicles Test Procedure’. Except, much like a man in rehab, we’re missing H. We don’t know why the ‘H’ doesn’t make the grade, except for the fact that the old one was called NEDC and our groundless theory that they wanted to avoid acronym bloat.

    In the simplest terms, WLTP is a way to test new cars to see how much fuel, or energy, they use, how much planet-killing gas they expel, and how far they can go on one tank / charge. The old test, called the New European Drive Cycle, was about as close to real life as your average Instagram feed, so some clever clogs came together to create a more accurate test.

    We’re in flux at the moment, as the old standard is retired and the new one comes into effect. So, if you’re getting close to the manufacturer’s quoted economy and range, it’s safe to assume they’ve used WLTP figures. If that 500-mile range is pie lodged so far in the sky that the cream on top is, in fact, cirrostratus clouds, you’ll be unsurprised to see a heavily asterisked NEDC estimate.

  • NEDC


    The old way of testing the efficiency of cars, except for the fact that the test was about as strenuous as the one given to rich kids trying to get into private school.

    There was a lazy roll up to cruising speed with the air-conditioning, lights, fan, wipers and everything else off, a gentle deceleration, and some time spent stationary. The cycle was repeated a few times with the cruising speed going a bit higher, before one last lazy ascent to 120km/h and returning to rest.

    Needless to say, it wasn’t the most arduous test but, even so, manufacturers would try to game the system by overinflating tyres, removing parts, or (and you saw this coming) programming the car’s engine computer to recognise when the car was being tested and run the engine completely differently, cheating on one of the easiest tests ever devised.

    So when WLTP came in, no car's economy actually got worse in real-life – just the official economy figure changed. It's like if you weighed yourself on the moon and got a reading that'd embarrass athletes, then did the same thing back in the real world. You see what we're getting at.

  • RPH


    The Range Per Hour, or how much range you’ll add to the battery in an hour’s worth of charging. It’s an equivocation, really – it can be hard to conceptualise what 10kWh means, but if you charge for an hour and get another 100 miles of range, that’s easy to figure out, regardless of how few metaphorical light bulbs are on upstairs.

    More efficient cars make better use of the energy you pour in. You can get 10kWh from a 50kW charger in 12 minutes. So a car that does four mpkWh can go 40 miles, but a three mpkWh car can only do 30 miles. That equates to 200 and 150 miles of range per hour respectively.

    Thanks to high-power DC chargers, RPH is increasing out on the highway. If you’re a Tesla Model 3 owner and hook up to a 120kW charger, you can get another 170 miles with just 30 minutes of charging – or enough time for a snack and a ‘comfort break’. As a range per hour figure, that's 340mph. And yes, as a collective, we've landed on mph for how much electricity you're adding to your car. That won't be confusing in the slightest. 

    It must be said that you won't actually add 340 miles by sitting there for an entire hour, because, after a while, charging slows down to preserve the battery. And unless you were on the electric car equivalent of fumes, there isn't 340 miles' worth of juice to put back in a Model 3 battery. The mph figure for adding range is like mph for speed –  it can be an instantaneous measure, or an average. Car makers tend to quote the instantaneous peak for miles of range added, so it's the absolute maximum you'll be able to achieve for a short while. But, like we said, adding 170 miles of range in half an hour is entirely possible, and is generally as easy as plug and play.

    Eventually, charging at this speed will help remove range anxiety, and the obsessive desire for full batteries. You don’t need a full tank of petrol to drive because it doesn’t take long to fill up. Similarly, if it doesn’t take very long to recharge, it won’t matter that your battery isn’t full.

    If you’re looking to save money on charging, the best idea at this stage is still to charge at home as often as possible, setting a smart charger to turn on late at night, when the energy tariff (rate) is as low as possible. Unless you have solar panels, in which case set the timer to run in the hours of daylight.

  • Regen


    Regen is how the BBC explains replacing the actors in Doctor Who. It’s also industry shorthand for ‘regenerative braking’. It’s a unique benefit of electric cars, including hybrids.

    Imagine, if you will, that every time you coasted down a hill or braked gently in your dino-juice-powered car, you added a little fuel back into your tank to use later. That’s really what you’re achieving with regeneration.

    Electric motors work by using electricity and magnets to spin a shaft. It’s a lot more complex than that, but this’ll work for our analogy. So, if you were to spin the same shaft manually, say, by coasting, you’ll generate electricity. It’s the same principle used in generators and in diesel-electric locomotives, where diesel power spins the shaft and generates electricity, because generators are basically motors operating the opposite way.

  • Range


    The distance between the lowest and highest note a singer can hit. David Bowie had a four-octave range, and Mike Patton has an astounding six-octave range. We can do two. In a pinch. If we’re drunk enough, and someone lets us near a karaoke machine.

    As you might have guessed by now, it’s also how far you get in your car from the amount of energy you put into it. So, it’s been fuel from the tank for most of your life; now (or soon), it’s power from a battery.

    When it’s a 10-minute exercise to pull in, fill up and pop off, there’s no real issue. But when it takes ages to refill, range becomes a real problem. Which leads to…

  • Range Anxiety

    Range Anxiety

    The fear that your vocal range isn’t big enough to hit the high notes in Bohemian Rhapsody. And we’ll let you in on a secret: it probably isn’t. With this joke becoming as dangerously thin as a catwalk model, let’s move on.

    Because electric cars are an emerging technology, there can be gaps in the infrastructure. What this dry sentence alludes to is the prospect of being very far from home, on a dark and cold December night, without enough power to make it to a charging station. Which then leads to the prospect of spending said dark and cold December night standing by a powerpoint, furtively stealing someone else’s electricity at a rate that’ll give you enough electrons to get home... if you sleep in your car overnight.

    Manufacturers have, so far, attempted to solve this by building ever-larger batteries with bigger kWh ratings. But that has its drawbacks, too – a safe estimate for power storage per kilogram of an assembled battery pack is about 100 to 150 watt hours per kilo, taking into account cooling, wiring, protective case and so on. Scaled up to be useful in an electric car, we’re looking at a battery that weighs somewhere between 660kg and a 1000kg to net 100kWh. So you’ve a huge weight penalty to overcome with bigger, more powerful batteries, that works against the extra power reserve. Because it’s always going to take more oomph to shift a two-tonne car than something featherweight. For more information, consult your nearest Lotus nerd.

    Also, every kWh has an environmental and fiscal cost. If we don't have to mine, prepare and package hundreds of kilowatt hours into each car, we won't churn through lithium and rare-earth metals quite as quickly. Which means that the plan to dredge parts of the ocean we haven't even explored yet to bring up metal deposits from deep-sea hydrothermal vents won’t have to go ahead. Yes, that is a plan, not a script from Captain Planet. Surely, there's a better way, right?

    But what is the alternative to a hugely expensive and heavy electric car? Oh, we don't know... how about smaller, more efficient cars, like we've been doing with petrol-powered machines ever since we figured out that five miles per gallon wasn't really in anyone's best interest? Crazy idea, we know.

    In the short term, the solution to range anxiety is more fast charge stations, so that at least you'll be able to use all the range you've paid for, rather than having to recharge with lots of capacity remaining because you can't safely get to the next charger. If chargers go from 50 miles apart to 20 miles apart, that's the equivalent of giving 30 miles extra range to every electric car on the road, and might finally mean you don't have to lug around a literal tonne of batteries wherever you go.

  • Li-ion


    What Snoop decided to call himself when Dogg wasn’t doing it for him any more. Anyone sick of this ‘misunderstand definition for amusement’ schtick yet? No? Excellent.

    So, Li-ion is a contraction of Lithium-ion, which is a method of storing power in a battery pack. The 12V brick used to start your petrol-powered car is a lead-acid battery, for instance, and some Toyota hybrid high-voltage batteries are another kind called Nickel Metal Hydride, or NiMH. NiMH is also common in rechargeable AA batteries, but less so now that Li-ion is getting cheaper to produce, thanks to market forces, supply and all the other things that bore us to tears.

    There are scores of different mixes going on inside batteries – alkaline (zinc-manganese), nickel-cadmium, silver-zinc and any number of others. But they’re all proven technologies for storing electricity and deploying it later on.

    Just to make things confusing, Li-ion is actually a group of batteries, because there’s more than one way to electrocute a cat. Inside the cells, the electrodes (i.e. vital battery bits) can be made from metals such as cobalt, manganese and nickel. Clever clogs the world over are figuring out how to get better performance and reduce cost by fiddling with the innards of Li-ion batteries, with a new, better way promised every week or so. Also, sources of cobalt tend to be plagued with both environental and human rights horrors. That's (at least one reason) why chemists are also finding ways to reduce or eliminate it from future batteries.

  • Solid-state battery

    Solid-state battery

    Solid State is the protagonist from that fantastic game, Metal Gear Solid. At least we think it is. It has been a while since we played. A solid-state battery, on the other hand, is a type of battery that could transform Li-ion batteries. But, barring a few inordinately expensive prototypes and news of ‘breakthroughs’ by various tech companies, it hasn’t revolutionised batteries in the way its proponents were hoping for. At least, not yet.

    Here’s how the whole thing works. In general, Li-ion batteries use a heavy, flammable liquid electrolyte (the bit that conducts electricity). So they’re heavy, and need a whole suite of cooling, regulating and protective bits to ensure they don’t go up like those Samsung phones did. Which is also heavy. And that’s why lithium is light but batteries weigh literal tonnes. 

    In solid-state batteries, the electrolyte is dry, much lighter, and not given to catching fire, which is handy. So all the flame-avoiding bits aren’t necessary. As Captain Obvious would doubtless mention, this makes them lighter again.

    Ol’ Cap would also point out that lighter batteries offer serious advantages for the weight of future electric cars. They’re easier to cool, too, which means you can charge them more quickly before they get too hot. Also, it feels like we should mention the not-burst-into-flames bit again.

    So, lighter cars that you can refill more quickly and aren’t lugging around flammable material? Sounds pretty promising. But there are more than a few problems to sort out before we get there – huge expense, limited charge cycles and many more – including something called dendrites, which sounds like something old people put on their dentures but are actually little stalactites in the battery that tend to break important bits. And fixing these problems is hard. Toyota had planned to use solid-state batteries in cars by 2025. The Dyson car was due to get them sooner. Toyota's dates slipped back; Dyson abandoned the car project altogether.

  • Supercapacitor


    A capacitor from the planet Krypton, stranded on Earth after the destruction of its home planet. Lives in the Fortress of Solitude. Works at a newspaper. How are we selling this... well? We think well.

    Anywho, a capacitor is an electrical tool with so many uses – the mere fact that you’re reading this is only achievable with the use of capacitors in the nation’s power grid, however many that help run the Top Gear servers and the handful in your phone or computer.

    Essentially, capacitors store electrical charge, which can help smooth out power delivery, or deliver a huge spike of power instantaneously, like you’d find at the wrong end of a stun gun.

    So, you might be wondering, why don’t we use capacitors instead of batteries in our cars? Well, for much the same reason as we don’t use steam engines: there’s a better way. You see, per kilo, regular capacitors store a tiny fraction of the energy that batteries can, so they don’t really work as a car’s main energy storage.

    Enter the supercapacitor – these can hold hundreds of times more charge than a regular capacitor, can charge and discharge more quickly than batteries and can tolerate more charge and discharge cycles – basically, more times charging it and driving around – than batteries. But they’re still not as energy-dense as batteries, so you’re unlikely to see them used in EVs in place of batteries.

    So, even though your power comes through more slowly with a battery, there’s going to be more energy in reserve. And please, go try a Tesla in Ludicrous mode, then come back and tell us you need a bigger power hit in one go.

  • PiCG


    Genuinely, if you come across this mystifying contraction, you’re likely mere moments from being bored to death. For somewhere between a poofteenth and a picosecond, PiGC stood for the Plug-in Car Grant, or the money Her Majesty’s Government contributes to the purchase of plug-in cars that can travel further than 70 miles without any emissions. The scheme also contributes to electric motorbikes that do more than 31 miles between charges and mopeds that can do 19 miles between charges. For a car it was £5000, then fell to £3500, and is (at least for a little while) £3000. Also, it only applies to cars that are £50,000 or under.

    Even on the government’s website, it’s called the Plug-in Grant – probably because it extends to motorbikes, mopeds, trucks, vans and taxis – definitely not just cars. So, that's a government PiG that you're actually grateful for, then?

  • EVHS


    The Electric Vehicle Homecharge Scheme, or the few hundred pounds you can claim to install a fast(ish) charger in your house.

    On regular household power, you can generally choose between 3.6kW and 7kW, which will, respectively, charge at 1.5 and three times faster than just plugging into a regular wall socket.

    If you’re a lucky sod and have three-phase power, you can get a 22kW charger installed, which is about 10 times faster than a regular wall plug. But it's not as lucky as it sounds, at least for charging electric cars – very few cars sold in the UK can use three-phase AC, so you're unlikely to be any further forward. If they do – the Audi e-tron and various Teslas spring to mind – it's usually at a maximum of 11kW, not 22kW.

    In some cases, getting a home charger installed can require a full redo of your household electrical wiring, too. If you live in the city, this is much less likely, due to the fact that we have technological advancements such as proper power grids, indoor plumbing and 24-hour off-licences.

  • OLEV


    You can almost guess this one, can’t you? Something, something, Electric Vehicle, right? Wrong. Because no one ever prospered by making things easy for someone else to understand, the OLEV stands for the Office for Low-Emission Vehicles. That’s the government department tasked with supporting Ultra-Low Emission Vehicles, or ULEV, but definitely not super-cool magnetically levitating trains, or Maglevs. For shame.

  • CCZ


    Or what we’ve just called the Congestion Charge part of London. Because 'part' doesn’t sound official enough, it’s called the Congestion Charge Zone by official (and officious) types.

    The gist, in case you’ve not been to London – and the prospect of coming here is akin to going straight to hell – is that the area around the centre of London (or Dante’s ninth circle, if we’re continuing that particular analogy) is plenty crowded enough with Italian teenagers, lingering street-dance performances and people going to Zara. What it needs, like a spare hole in the head, is you gumming up the roads and getting in the way of buses, taxis and chrome-wrapped Lamborghinis on their way to Harrods.

    So, from 7am to 10pm, it's £15 to drive in this zone. It used to be cheaper and apply over fewer hours, but it's been 'temporarily' hiked to cover post-COVID costs for the authorities. But, with an electric car (which they call a zero-emissions vehicle), you can pay a one-off £10 for an exemption that lasts a year. Top Gear has done this successfully with its long-term-test Jaguar I-Pace and BMW i3.

  • ULEZ


    We’re going to ride right past the obvious joke and tell you the simple, easy fact: this suggestive acronym adds to what Londoners have called the Congestion Charge bit since 2003. That’s right – the ULEZ doesn’t replace the CCZ; it’s a separate and additional charge that just happens to apply to the same area. It operates in the exact same area as the CCZ, just for a very different reason: the CCZ is there to ease traffic; the ULEZ is to ease pollution. Birmingham and Glasgow have similar schemes in the works, too; Bristol and Leeds had plans but are now reconsidering them in the wake of the pandemic. So let’s just focus on the London ULEZ.

    The ULEZ is in effect every hour of every day, and will rain down with great vengeance and furious application of a £12.50 charge if you drive into the zone in a petrol car that doesn’t meet Euro 4 standards or a diesel car that doesn’t meet Euro 6 standards.

    The good news is that if you’ve got a fully electric car, you’ll be as safe as houses, regardless of when and how those standards change. If your car doesn’t emit anything, it is – shockingly enough – unlikely to fall foul of emissions regulations. Or congestion regulations, because... reasons.

    If you live within the Ultra Low Emission Zone, drive a London taxi, drive a car “with a 'disabled' or 'disabled passenger vehicles' tax class” or, excellently, a classic car if it's more than 40 years old, you’re entitled to a reduction in fees, a temporary grace period or a complete exemption. But, being the savvy kind of person you are, you’d never think about taking an article on a car website as gospel and then acting accordingly, would you? No, of course not – you’d head to the TfL website and find out for sure if you’re on the hook for an amount that could get you... whoo, nearly two pints in London.

    The Ultra Low Emission Zone sits (in general terms) to the east of Hyde Park, south of Regent’s Park, west of Whitechapel and north of Vauxhall, the same as the Congestion Charge Zone. But the plan is that, by November 2021, it’ll comprise everything within the North and South Circular roads.

    Just for context, have a look at the King’s College annual London air pollution map. The red zone is where the ULEZ has been applied. The white zone is for loading and unloading only.

    The upcoming extension of the zone to sit inside the Circular roads pretty neatly encompasses everywhere in London with moderate to high levels of air pollution. And, entirely coincidentally, the Top Gear office.

  • FCEV


    The Fuel Cell Electric Vehicle, also known as that Honda FCX Clarity you saw on Top Gear telly a few years back, and that Toyota Mirai you’ve never seen in real life.

    The crux of the idea is that, in the natural world, hydrogen and oxygen like to be together. This is what scientists refer to as water, and what we at Top Gear refer to as ‘the reason that London is as grey as a businessman’s suit for six months of the year’. But we digress.

    Much like a teenager and their phone, it takes a lot of energy to separate hydrogen and oxygen – if they’re already together as water. But if they’re already apart, reuniting them in just the right way releases energy. Burning hydrogen is the most obvious way, but definitely not the best way. See also: the Hindenburg.

    However, if you get hydrogen and oxygen back together in a special cell that has the same basic idea as an electrolysis cell – anode, cathode and all that stuff you learned about in high-school science class, but operating in reverse – you generate electricity, which we’re told is quite useful if you want to make an electric car work.

    And, just to indulge in a little trousers-too-high pedantry, we should point out that fuel-cell vehicles are technically hybrids, in the sense they also have a buffer battery, but absolutely no human being is boffiny enough to refer to them as FCHEVs.

    We also should point out that getting hydrogen from water via renewable electricity isn’t the only way – it can come from fossil fuels, too, if one were so inclined. And, while that does negate a lot of the good of electric cars, there’s a silver bullet: an FCEV will only ever put out water vapour from the exhaust pipe, which has a massive effect on pollution.

    It's also easier to move hydrogen over long distances than electricity. So you could have distant offshore windmills or desert solar farms, use that electricity on the spot to convert water to hydrogen, then pipe or ship the hydrogen to where the cars are. Not flawless, but still leagues better for the environment than fracking and drilling and so on.

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