All modern EVs have chargers built-in. So what's that charging unit you plug into at home or at the grocery store? That's called an EVSE, short for Electric Vehicle Supply Equipment. More colloquially, they're called "charging stations" or "charge points" (not the be confused with the company called "Chargepoint" which we'll discuss in a bit). So, now that we've got the lingo out of the way, let's talk about charging.
Just like different smartphones use different types of charging cables, EVs use different types of connectors, too. In the U.S., the car you choose will have one of four different charging ports. It’s critical to understand the different plug types, because you’ll want to make sure that the car you buy is compatible with the charging stations in your area, as well as those along the routes that you’re most likely to drive.
Most public charging stations operate as part of a “network”. A network is a company that manages many charging stations, and facilitates payment.
Some charge stations are free to use, but many will require payment. Not all charging stations have the ability to accept payment at the plug, so for these you'll need to visit the network's website or download their mobile app, creating an account to activate the charge session. As you can imagine, arriving at a charging station and having to fumble with new apps and creating accounts can be kind of a pain. The good news is, you can sign up for most of the major networks in advance, and be ready when you arrive at the plug.
Some charging stations do accept payment at the plug, and some do but are limited to tap-to-pay methods. Overall it can be a very inconsistent experience, so we recommend downloading these apps in advance so you're ready. We'll cover the ones you should know about later in this lesson, in a chapter titled "Guide to EV Charging Networks".
Some charging stations charge faster than others.
Some are very fast, and meant to be used for quick stops while on the go, like the electric equivalent of stopping for gas. Others are slower, charging over the course of hours, not minutes. We’ll cover this in depth in the next chapter, for now just know that when shopping for a car, how fast it’s able to charge is related in part to the types of stations it’s compatible with.
Some cars charge faster than others.
Every plug-in EV has a maximum speed at which it can charge, called Maximum Charge Rate (or Peak Charge Rate). If the Max Charge Rate of the car is lower than the charge rate of the charger it's plugged into, the charging station's speed will be limited by the charger in the car. Charging speed is measured in kilowatts (kW). The higher the number, the faster that car can charge.
The fastest-charging EVs on sale today charge at over 250 kW. If a car capable of charging at 250 kW finds a charger that is capable of delivering 250 kW, you should be able to charge 80% of your battery in just over 20 minutes. That’s pretty quick!
If your car is only capable of charging at a max of 55 kW, and you arrive at that same 250 kW charger, you’ll wait closer to an hour for the same amount of charge.
Would you rather wait 20 minutes or an hour? That’s why it’s important to consider Max Charge Rate when choosing your EV.
We just discussed “Maximum Charge Rate”, and the key word there is “Maximum”. There are a number of reasons why your charge rate may be slower than the maximum, and most charge sessions will fluctuate speed as they charge (something called a "charge curve").
Let’s say your car is capable of charging at an impressive 250 kW, and you pull up to a fast 250 kW charging station. You plug in, but your dashboard says you’re only charging at 100 kW? What gives? Why is it taking longer than it should?
If your car’s battery is too hot or too cold, charging speeds will slow down. If your car’s battery is already near full, it will charge much slower than if it was completely empty. If there is another car charging and those two plugs share the same circuit, the available power could be split between both cars. For now just know that charging speeds are conditional, and may vary from session to session. We’ll talk more about how to anticipate these charge times later.