When using a fast charger for your electric vehicle (EV), you may notice that it stops at about 80%. Countless charging stations throughout the United States feature fast chargers. Also known as rapid chargers, they live up to their namesake by quickly charging EVs. Rather than charging all the way to 100%, though, many of them only charge to about 80%.
The Basics of Fast Chargers and How They Work
To better understand why fast chargers stop at 80%, you must familiarize yourself with their functionality. Fast chargers are designed to charge EVs using direct current (DC). This is in stark contrast to level 1 and level 2 chargers, both of which charge EVs using alternative current (AC).
DC supports higher voltages than AC, resulting in faster charge times. Fast chargers are characterized by the use of DC. You can still charge your EV using a level 1 or level 2 charger. Both of them, however, use AC, so they will charge your EV more slowly.
Charging Slows Beyond 80%
Back to the question at hand: Why do some fast chargers stop at 80%? This is due to the fact that charging slows dramatically beyond 80%.
Depending on the particular type of fast charger, as well as the EV with which you use it, it may charge to 80% in less than a half-hour. Based on this information, you may assume that a fast charger will charge from 80% to 100% in 10 minutes or so. This isn’t the case. Charging speeds drop at about 80%. It may take a fast charger a half-hour to charge your EV from 0% to 80%, and it may take the same fast charger another half-hour to charge your EV from 80% to 100%.
Get Drivers Back on the Road
Another reason fast chargers stop at 80% is to help drivers get back on the road. Most fast chargers are found at charging stations. Charging stations sell charge time to drivers. If you’re in the middle of a road trip and your EV’s battery is running low, you can make a pit stop at a charging station.
By configuring their fast chargers to stop at 80%, charging stations encourage drivers to get back on the road. It promotes faster pit stops while moving drivers in and out of the charging stations more quickly.
Not all chargers will charge EVs to 100%. As revealed here, some fast chargers stop at 80%. This is because charging — even with DC-based fast chargers — significantly slows beyond 80%. And by stopping at 80%, charging stations can get drivers back on the road.
