If you are charging an EV at home, charging speed is not a very important consideration. The car will be sitting idle for 10 hours or more. You will start your day knowing you have plenty of battery power to meet your daily driving needs. When you get back home at the end of the day, plug in and the charging process begins all over again.
But what if you have a long commute that requires you to charge along the way? Or maybe you are on a 6000 mile long journey in an EV like a Volkswagen ID.4. Then a new factor becomes important — charging speed, a concept that drivers of conventional cars don’t understand and even many EV owners are a little fuzzy about.
Charging speed is a the combination of a number of factors. Battery chemistry is one but that’s not the whole story. Every EV has a battery management system that sits between the battery and the charging port. It monitors the state of charge and temperature of the battery. When we shove a lot of electrons into a battery in a short period of time, things heat up internally. The BMS controls the flow of electricity so nothing gets too hot during the process.
Every manufacturer designs its own BMS. Some prefer to err on the side of caution to keep the risk of fire to a minimum. In theory, the battery could charge faster but the BMS prevents it from doing so as a safety measure. Temperature also plays a role. Batteries don’t like being charged in very hot or very cold temperatures. It is part of the job description of the BMS to know the ambient temperature and make adjustments accordingly. Each EV model has what is called a charging curve but finding that precise information can be tricky, Bloomberg says.
Another factor is efficiency — which is how far a particular EV can travel on a given amount of electricity. A car that can drive 5 miles for every kWh of energy in the battery will simply need to be charged less often than an EV that can only go 3 miles per kWh. For example, the Rivian’s R1S three row SUV uses twice as much electricity per mile as a Tesla Model 3, according to Edmunds testing, and will therefore need more frequent charging.
Edmunds Does Its EV Home Work
To assess charging speed, analysts at Edmunds recently tested dozens of vehicles in the US by charging them from 10% to 80% using high speed chargers. Then they determined how long, on average, it takes to add 100 miles of driving, based on the real world driving efficiency for each vehicle. Results ranged from less than 7.5 minutes for the Hyundai Ioniq 6 to almost 35 minutes for the Chevy Bolt EUV. (TheTesla Model 3 came in sixth at 10.6 minutes). “The conversation now is going past range, which dominated for so long,” says Jessica Caldwell, head of insights for Edmunds. “It’s range, it’s infrastructure, it’s how long these cars take to charge.”
The next issue to consider is charging power — which measures how fast a charger can shove electrons into a battery. The minimum for a DC fast charger is 50 kW, which was a lot 5 years ago but is pretty wimpy today. Many newer chargers today are rated at 350 kW or higher. The standard for federal funding under the NEVI program is at least two 150 kW chargers in each location.
Finally, there is the issue of how much power an EV can accept. The Chevy Bolt, soon to be taken out of production, can only accept a maximum of 55 kW. Many vehicles like the Ford F-150 Lightning top out at around 150 kW. The one thing we know for certain is that if you are driving either a Bolt or an F-150 Lightning and plug in to a 350 kW charger, you are going to get some dirty looks — and perhaps a nasty word or two — from other drivers whose cars can accept higher charging power and are waiting for that high power charger.
Bloomberg Green has come up with a matrix that rates every car tested by Edmunds according to how long it takes to add 100 miles of range combined with a ratio of its MSRP to its total range. The results put the Hyundai Ioniq 6 at the top of the list, followed by the Kia EV6 and Ioniq 5. The Tesla Model 3, Model Y, and Model S were next. (The Model X was not included as it was not rated by Edmunds.) If you are going to pack a lot of miles on your EV, those six cars are the best choice for your money as they have high efficiency, can charge quickly, and are relatively affordable.
Putting An EV To The Test On A 6000 Mile Trip
David Carlson lives in Montana and drives a Volkswagen ID.4. When planning a road trip to New England and back, he did what drivers used to do. He planned the trip in advance in order to avoid getting stuck in East Overshoe or South Succotash without enough electrons to reach the next charging station. People used to do things like that and some even enjoyed the experience. Yes it requires more thought than just getting behind the wheels and hitting the gas pedal, but it has its own rewards. Carlson writes,
On a typical travel day, covering 400 to 450 miles, I needed successful connections at three or four different charging stations. Each day, I started with at least an 80% charge. I would calculate the distance to the next charging location in advance. Because the PlugShare app showed likely charging vendors at each location, I preloaded Electrify America, ChargePoint, EVconnect, FLO, and Ivy apps with credit card information and money. Once I connected at a charging station, I repeated the process, charging to 80% or greater and calculating how far to the next charging stop of the journey.
Chargers were scarce near his home state but became more prevalent as he headed east.
I learned as I moved. I tried to keep moving eastward (later, westward) while also recognizing ever-present uncertainties about where to charge next. I found I could rely on Electrify America stops for ease of connection, reliability, and prominent locations. A westbound EV driver filled me in on new services available in Chamberlain, South Dakota. And I dealt with an unexpected problem in Quebec: Despite the apparent abundance of charging options, very few worked with U.S. credit cards, even though those same cards worked in motels, restaurants, and grocery stores.
Carlson says most of the places he stopped to charge at were empty or nearly so. “From connect to disconnect, it typically took 39 minutes to charge my car, though the total time varied from a low of 25 minutes to a high of 69 minutes. Occasionally, I would accept longer wait times to charge to ‘safer’ levels of 90% or even 100%. I proceeded cautiously, knowing that the range or efficiencies on my dashboard display might prove overly optimistic.”
Things To Do While Charging Your EV
What does one do while waiting for an EV to charge. Carlson says he “used bathrooms, dumped trash, and perused local stores. If I had extra time, I might take a picture, go for an exploratory walk, eat a snack, or read a few pages of my book. When possible, I compared notes with other EV drivers. Although I often visited charging stations at odd hours, I rarely felt hurried or unsafe.”
There were a few instances when Carlson needed help from customer service to get a charging session started but all went smoothly after that. “I traveled from Montana to Maine and back using an electric vehicle. Most people noticed no difference between my white VW EV and any other white SUV-sized vehicle. Those who knew about my EV seemed amazed at my successful arrival if somewhat confused about the effort required. Several people regarded the charge port with curiosity but bewilderment. ‘You mean it doesn’t use gas?’ ‘You charge it through that port?’
Would I recommend others to consider a similar trip? Yes. Charging my vehicle, largely an unknown factor before the trip, proved — for the most part — routine and easy. That said, charging infrastructure for EVs remains under development in most places. EV drivers need better charging stations at more locations. And charging systems need stability, reliability, and better data products. At the moment, many EV owners tolerate the chaos. We anticipate that improvements will emerge, soon.
An EV is different than a conventional car. Where yesterday we thought in terms of torque and horsepower, today we think in terms of range, charging curves, and charger power. That makes driving an EV more of a contact sport, one that involves our brains as well as our bodies. Some people don’t want that deeper level of connection with their cars but most of us appreciate the opportunity to be more engaged in the journey.
Carlson is right. Charging infrastructure is improving and tales of being stuck somewhere on a rainy night hell and gone from the nearest charging station are less common than they were just a few years ago. Most manufacturers have now installed software that will help you find available chargers along your route, which can reduce any anxiety about taking an EV on a road trip.
In general, if you want to drive an EV, educate yourself about its range, efficiency, and charging speed before you sign on the dotted line. When you have done your due diligence, get in, punch the exhilerator, and drive happy.