EV Illiteracy: How to Spot Bullshit / by William Watts

On Saturday, while waiting to check out at Whole Foods, I saw a sleek magazine from Centennial Spotlight slotted in the rack between towers of bottled electrolyte water. The magazine was ambitiously titled “The Complete Guide to Electric Cars”, and the blurbs on the front promised not only "expert reviews " of some of the newest EVs, but also tips on "maximizing range" and "home charging." Intrigued, I bought a copy.

That was a mistake. The “guide” was riddled with glaring factual inaccuracies. I just wish I could say I was surprised.

We have a serious EV literacy problem in this country. Now, let me be clear: I’m a car guy. Actually, I’m interested in just about anything on wheels. I was 15 when I took apart my battered 1972 Datsun 240Z and put it back together again, and in the two decades since, I’ve owned and retooled more bikes, motorcycles, ATVs, and cars than I can count. But as a car guy, I understand not everyone shares my interest. Certainly most people don’t have the time to learn the intricacies of inverters and battery management systems. Yet if the United States is to successfully transition from gas to electric cars, a lot more attention needs to be paid to basic consumer education about how EVs work–and, more generally, about how to think about charging, power, and energy.

It is understandable that many of the concepts behind buying and living with EVs would be foreign to most drivers today, as most have never driven an EV, let alone looked for the best charger in their neighborhood. But despite their best efforts, even intrepid EV owners can be stymied by the lack of information and even misinformation about how to maintain their cars, manage the costs of charging, and improve their day-to-day driving experience. 

Dealerships are the average consumer’s first point of entry into the EV world, but they are often ill-equipped to educate consumers on how to purchase or use EVs, and sometimes have to be dragged kicking and screaming into supporting them at all. So consumers are likely to turn to published resources, whether online or in print, to find the answers to their questions.

Cue the talking heads and “complete guides.”

The first few pages of this magazine were an innocuous history of EVs dating back to 1835. But this was followed by a particularly problematic glossary section that contained so many errors that I covered my copy with notes.

Nothing could be more flagrant than the magazine’s nearly constant confusion about the difference between energy and power and repeated mix-up of the units used to measure each. For example:

Level 1 - This is the slowest and least recommended way to charge a vehicle, as it is merely an AC plug connected directly to a standard household outlet. It provides a scant 2.3 kilowatts per hour (kWh)

In fact, most circuits in the US can provide only 1.5kW, but the main issue here is that a kWh is a measure of energy, not of power. Charging power is measured in kW, not kWh.

Level 3 - Known as a DC charger, this is currently the fastest way to charge an electric vehicle with speeds of up to 250kWh.

Again, DC chargers today  can be as fast as 350kW, and again, a kWh is a measure of energy, not of power. 

Charging from home, consider the average cost of a kWh to be about $0.15, so an EV with a 66-kW battery would cost about $10 to fully charge at home

This one is particularly frustrating because it gets  the first unit right, but misses the landing on the battery size (which should be kWh). 

Confusing energy with power is not a minor mistake. In the context of an EV, energy describes the amount of electricity that is stored in your battery and determines how far your car can travel, while power is the rate at which that energy is removed from the battery to propel you forward. So, other things equal, a car with greater battery capacity (typically measured in kilowatt hours, or kWh) can travel more miles, while a car with an electric motor with a higher power rating (measured in kW) can accelerate more quickly.

Put another way, power is the amount of electricity used at any instant, as reflected in the units used to measure it: for example, a kilowatt is a thousand watts, and a watt is simply a joule of energy used per second. Energy is simply power multiplied by time. Putting the two concepts together, a space heater requiring 1kW of power running for 1 hour uses 1 kWh of energy. To compare the units to something more familiar, 1kW is equal to about 1.34 horsepower.

An EV charger rating is a power rating: it represents how fast electrical energy can be transferred from the charger to your EV's battery (at least in theory, even if not in fact). But you are billed for your charger use based on the amount of energy you put in your battery, which makes paying per kWh for an EV a lot like paying per gallon for a run-of-the-mill internal combustion engine (ICE) car. An EV owner might have a 100kWh battery, pay $.30 per kWh to charge at a 150kW public station, and go from 20% to 80% charged in about 30 minutes.

Some other egregious errors:

The PHEV(Plugin Hybrid Electric Vehicle) is the most commonly seen type of hybrid vehicle and is usually what first comes to mind when people use the term ‘hybrid car.’...Nonetheless, plug-in hybrid vehicles remain the most common and popular solution for American Drivers

This is the exact opposite of the truth. In fact, HEV (non plug-in Hybrid Electric Vehicles) were first to market and so synonymous with the archetypal Prius that Toyota had to add ‘Prime’ to the model name to distinguish the plug-in version. More to the point, even as recently as February, HEVs outsold PHEVs four to one. The section then goes on to list the Audi e-tron as an example of a PHEV. But that’s wrong again: the e-tron is Audi’s sub-brand for its full electric models. 

Level 3 Charging - Also known as DC charging, it charges at 480 volts with a direct current (DC) plug. It takes 30 minutes to charge an EV with a 100-mile battery.

This makes no sense as a way to think about charging speed.  For starters, charging voltage for a DC charger can be anywhere from 200V to 1000V, and charging time depends on the car and the rating of the charger itself. That said, what car has a “100-mile battery”? I’m aware of only one EV with such a limited range that can fast-charge, the Mazda MX-30. Presumably, the author meant a car takes 30 minutes to get 100 miles of range. But in any event, a more accurate statement would be “typical cars can charge to about 80% in around 30 minutes.” And depending on the car, 80% can mean a range of anywhere from 100 to 400 miles.

SAE Combo CCS - An enhanced Level 2 plug that supports DC charging levels of up to 170kW.

CCS Combo is the de facto standard Level 3 plug and supports charging levels of up to 350kW currently.

The magazine goes on to talk about upcoming tech from a company called uBeam that will “charge the battery via Wi-Fi with electromagnetic waves.” This vision–of “a safe way of beaming power to your devices,” from a company that has promised and failed to make the idea work for even phones since 2011–is preposterous. (To be clear, the so-called WiFi option is not the same as close-contact inductive charging, which has been around for a while.) The reference, by itself, makes clear this magazine is not to be taken seriously.  Now, I know that because I am an engineer working in the space. But you shouldn’t need a degree to filter out misinformation from a magazine whose entire contents are dedicated to EV education. Putting out this level of misinformation is borderline reckless, and will inevitably do more harm than good to consumers trying to educate themselves about what is likely the second-largest purchase they will ever make.