You’ll need to charge elsewhere occasionally. That’s when charging time becomes a big deal.
Charging an EV battery takes longer than the 5-10 minutes to fill a gas tank, but how long depends on a couple of factors.
First, voltage from the charger. Getting 250 miles of range when you’re charging overnight at home is good, but it’s a deal breaker if you’re going on a 300-mile trip.
In that case, you’ll want to look for a public 400v DC fast charger. They’re not as common as 240v public chargers yet, but you can find the nearest DC fast charger from the Department of Energy. Companies that build charging stations, like EVgo and Electrify America, have apps showing their networks.
Charging at 400v, a Ford Mustang Mach-E’s range goes from 5% to 80% in 45 minutes. That’s about 216 miles for an AWD Mach-E with the 270-mile extended-range battery.
But why stop at 80% when we fill the gas tank to the brim? Because batteries are different from fuel tanks.
A fuel tank is like a bucket of water, a single container. An EV battery is more like an ice tray.
The Mach-E’s extended-range battery pack consists of 376 individual batteries. When all of the cells are near empty — about a 5% charge — fresh electricity immediately finds an open cell. As each cell reaches capacity, the battery controller finds another that still has room for electricity, and monitors as they top up, like when most of an ice tray’s compartments are full.
Charging to 80% is easy and fast. Finding space for the last 20% could take as long as the first 80. The most time-effective thing is filling to 80, getting back on the road and filling to 80 again when the battery runs low again, rather than charging for three to four hours and getting only an extra 54 miles.
There’s another factor: your EV’s onboard charger, which regulates how fast the battery can accept electricity. For instance: The Mustang Mach-E adds 216 miles of charge in 45 minutes and has an 11 kW onboard charger.
The Chevy Bolt EUV has a 7 kW onboard charger; connected to the same 400v, it adds 95 miles of charge in 30 minutes.
The holy grail all automakers chase is a full charge in 10 minutes. They’ll probably achieve it, but nobody knows when.