The automotive world is shifting from internal combustion to electric this decade. This shift will require updates to our general automotive knowledge and terminology. Everyone who owns a car now has at least a working knowledge of fuel pumps. But there are multiple ways to charge an electric vehicle — at home and on the road. And understanding how electric currents work — if it's been a few decades since you took a high-school science class — can be unfamiliar and confusing, even to car enthusiasts.
Here's what you need to know about EV charging levels.
Level 1 Charging
Level 1 is the simplest EV charging method: plug the car into a standard 120V outlet. It's also the least effective. A Level 1 charger adds a handful of miles of range per hour. That is enough for a plug-in hybrid, which can fully charge overnight. An EV with a much larger battery could require days to charge fully on a Level 1 charger. But theoretically, an owner with a short commute could still get by charging on a Level 1 overnight.
Level 2 Charging
Home is where 70-80% of the charging happens. Most EV owners will spend a few hundred dollars to install a Level 2 charger in their off-street parking. A Level 2 charger uses the same 240V outlet a homeowner would use to power a dryer or oven. Level 2 chargers vary but can add more than 30 miles of range per hour — enough to deliver a full charge to an EV overnight. Level 2 EV chargers typically operate at between 32-48 amps. Most units you buy will have adjustable settings. Many public charge points will also be Level 2 chargers.
Level 3 Charging
Level 3 charging is often called "fast charging." Level 3 chargers use direct current instead of alternating current. They require a much higher voltage than one would find in a typical household (and cost a lot more to install), so you'll only really find them in public settings. Charging speed will depend on the vehicle, but a Level 3 charger can typically deliver a full charge from 10-80% in under an hour — on cars that can fast charge. EV owners who own a Level 2 charger will typically charge on a Level 3 only on road trips.
400V vs. 800V Architecture
Teslas and most other EVs currently launch with 400V fast charging capability. Some electric vehicles, like the Porsche Taycan and the Hyundai Ioniq 5, have 800V architecture. Using 800V theoretically allows vehicles to charge at speeds above 150 kW, which could cut the full charge (10-80% time) down to less than 20 minutes. 800V is likely to become the standard in the future. But the components needed to add it remain costly right now.
Bi-directional charging is also called vehicle-to-load (V2L) functionality. This capability allows the vehicle to send power back out to power equipment, a campsite or even a home during a power outage (or to cut costs during peak electricity rate hours). Teslas notably don't allow this. Other EVs like the Ford F-150 Lightning make it a selling point.
Why do you charge an EV to 80%?
Manufacturers typically give the charge time to 80% as the "full charge." Over time, charging fully can increase battery degradation, and most manufacturers will recommend not doing so unless necessary. Yes, this is true of your smartphone as well.
The more practical reason is charging times slow as the battery becomes fuller. Even on a "fast charger," it can take the vehicle as long to charge from 80% to 100% as it took to get to 80% from much less.