Charging Tech


ChAdeMO? 3.6kWh? SAE J1772? Trickle? Charger? EVSE?

There’s a lot to learn when it comes to electric car charging. Let’s begin with the basics, we’re now calling what we’re traditionally think of as “charger” an EVSE, this is because the actual charging is done by equipment within your EV. What the EVSE does is facilitate that. It’s also difficult to give easily digestible charging information because what people want to know is how many more miles I can go per hour of charging (after accepting empty -> full isn’t as relevant), which varies based on driving style.

Level 1 (a.k.a. trickle charging): Most EVs come with a level one EVSE. These allow you charge at a rate similar to 4 miles recovered per hour on a normal household outlet, like one you’d plug a toaster into. They’re portable, and come in handy to charge while out and about at the house of someone you know.

Level 2: These come in several flavors. Charging rates vary from about 3.6kWh to 6.6kWh about 20kWh (Tesla S) depending on what’s in your EV. They can pull anywhere from 12 amps to 30 amps, and even to about 80 amps (Tesla). Roughly speaking, for every hour spent charging you can recover around 12 miles on 12amp, 16 miles on 16 amp, 22 miles on 30amp, and around 62 miles using the tesla dual charger. Level two chargers are your bread and butter. It’s what you likely want installed at your home. This is what you’ll find the most at public charging stations. Standardization for this type of charging is currently the SAE J1772 connector. As to which station you purchase, that’s up to you really. If your EV can handle only 3.6kWh, there’s not much of a point in buying a 6.6kWh station because your EV cannot handle the extra power. A lot of owners have been opting to go with EVSE upgrade, which will upgrade your current level1 EVSE to be able to pull up to 20amps (essentially converting it to a mobile level two EVSE). This is especially handy for owners who have an existing electric dryer outlet to plug into. One caution with whatever station you purchase, be sure to have the right electrical run (verified with an electrician) and the right plug for the hardware you’re purchasing.

Quick Charge (QC): Not all EVs come equipped with this functionality (despite what salespeople will occasionally misrepresent, be warned), and their installations vary widely. These chargers, if present and compatible, will charge a car like the Nissan Leaf from 0-80% in about a half an hour. These are most useful on trips where you’re going to exceed the per trip range limits of the car significantly. Standardization for this technology comes in many flavors. Most in production QC chargers have standardized to CHAdeMO. The SAE-Combo plug is also widespread (or is slated to be soon). DC Chargers are being rolled out that accommodate both plugs, but the majority of the currently “in the wild” DC quick chargers are using CHAdeMO. At the time of writing there exists exactly one SAE-Combo charger (in San Diego, CA), and the Chevy Spark EV doesn’t have the option to come with one (nor can it be upgraded to later), but they do plan to release Sparks with it early next year. Tesla has their own system of superchargers and battery swapping, which is generally not for use by the rest of us.