The Electric Vehicle World was set abuzz recently through a demonstration by Chinese EV leader BYD of a car which could add 150 miles of charging range in around 5 minutes, a speed that suggested some similarity to a gasoline fill-up. Many potential EV buyers fear the slower charging times of existing EVs, leading to speculation that such a charge speed could remove this anxiety. While faster charging is something everybody would want, all other things being equal, all other things are most definitely not equal.
BYD has been light on details on this announcement, though they have said that two car models coming out shortly, such as the Han L and Tang L will support it, and while there are no such public chargers, they plan to deploy 4,000 of them in China. Zeekr has cars in production that charge at about 400kW, able to do a decent charge in 10 minutes, and 0-100 (which you never do) in 22 minutes. Tesla’s fastest will do about 170 miles in 15 minutes, Mercedes claims 200 miles in 10 minutes. Many companies have claimed fast charge abilities in the lab.
Here are some of the issues with a fast-charge like that promised by BYD:
- Most foreign experts fear it’s likely not fully real. You may only be able to do it rarely, or it may require a shorter-range battery. BYD would have needed to reach a major breakthrough to pull off all that is claimed.
- Megawatt charging stations will be very expensive to install, and will need special locations. As a result the cost of charging at such stations may end up much higher than slower stations, and vastly higher than Level 2 (overnight) charging that most EV drivers use for most of their charging.
- 150 miles in 5 minutes is still not gas pump speed (which for a hybrid car is about 10 gallons or 500 miles in one minute.)
- This sort of rapid charging is very rarely actually needed, so if the cost is high, it will be rarely used, and may be hard to find. But it is desired or needed some times.
Is it Real?
BYD’s competitors are highly skeptical. Current thinking in battery design suggests charging at this speed requires thin anodes and cathodes and thus less capacity. It’s true that if you could really charge this fast you might tolerate less capacity, as while you would make more charging stops they would be shorter stops. A smaller battery is cheaper, but wears out faster. Others suggest charging at this speed was always possible, but with high risk of battery degradation. BYD has not indicated how often the car could charge at this rate. On the other hand, since you only rarely need to charge this fast (see below) it might indeed be the case that you only do this when in a real hurry (such as an emergency trip.)
Supporting shorter range cars doing more charges requires many more chargers, which is an issue as these chargers will be quite expensive.
What Does it Cost?
The faster charging is, the more it costs. Today’s fast chargers tend to cost 2x-5x what it costs to charge slowly at home. Providing a megawatt is going to be expensive, and in fact it’s hard to bring megawatts into charging stations and takes time. (As a plus, since such stations can handle more cars per hour, the cost is shared over more sessions.) Even so, it’s likely a megawatt charge is going to cost a fair bit more than slower charges, and as such used more rarely. BYD did not respond to questions about cost. If it costs 50% more, people are likely to only use it when they truly need it. Most EV drivers in their own towns charge at home, and never or rarely use much more expensive public fast charging except on intercity trips.
Do You Need It?
Charging at this speed evokes “gasoline thinking,” a desire to charge EVs the way will fill-up with gasoline. While gasoline does pump 15 times faster than even the BYD charger, you spend time on other things than pumping so it can seem only modestly faster. Smart EV drivers try to avoid waiting while they charge and as such don’t care too much about the speed as long as it’s in the right range. They charge while sleeping at homes and hotels and while working at offices, and are fine with very slow charging, as they need not even be aware of the speed. When it comes to fast charging, a good plan is to always do it during meals. Meals tend to take around 40 minutes with counter service, and an hour with sit-down, so charging rates of around 100kW or less are perfectly fine–even too fast, as you often have to get up from your meal to move your car.
Sometimes though, you want a faster charge. You may not want a meal (or to visit whatever stores or attractions have the charger.) You may be in a big hurry. You may wish to stop only for a short bathroom break, where getting as much as you can in 5 minutes is the order of the day. (Even those who charge at lunch often need a bathroom break and charge around 4pm which is early for dinner.)
As such you don’t need super-fast charging most of the time, indeed you almost never need it, but you may wish it. People who don’t yet drive EVs and who have only driven gasoline style are often convinced they need it, and don’t learn otherwise until after they buy. Many feel such super-fast charging is needed to get these buyers into their first EV; they want to think nothing will change.
The big question is the cost. If ultra-fast charging costs double what 100kW charging costs, people will probably only do it when they really need it. If it’s only 20% more, they will do it when they want it. But almost nobody will do it all or most of the time. Perversely, with a charge that fast, you must wait as you will be required to move your car immediately. There might be time for a bathroom break or beverage purchase, but not much more. (Today at gas stations, people usually keep their hand on the pump, and don’t leave it unattended.)
Because these stations and their megawatt-per-station will be pricey, stations will probably not be very large. That runs the risks of contention if too many show up at once. The lines will clear faster than for regular fast chargers, but if you were keen on a 5 minute charge, any line completely changes the experience.
BYD’s fast charger, and other super fast chargers are an interesting development, and they will be useful, but only some of the time, because they are likely to cost a fair bit more. That means they are not a game-changer, except in that they can assuage the false fear that those who have not yet bought an EV have about charging being unbearably slow, and not as good as gasoline.
