A friend bought an electric car and, entirely reasonably, assumed charging was solved: the car came with a cord, the garage has an outlet, plug it in. That held for about a month, until he wanted to charge faster than the garage outlet could manage — and at that point the project stopped being about the car and became a question about his house. Charging at home isn't a purchase you install. For anything beyond the cord in the trunk, it's an electrical job that starts with someone qualified looking at your service, your panel, and your load.
Level 1 and Level 2 are two different projects
Level 1 charging is the cord that ships with the car, plugged into an ordinary 120-volt household outlet. It's slow — usually a few miles of range per hour — but it needs no installation at all, and for someone with a short commute and a car that sits in the driveway overnight, it can genuinely be enough. The U.S. Department of Energy's Alternative Fuels Data Center notes that Level 1 requires no installation cost and should be used on a dedicated circuit.
Level 2 is the wall unit people picture when they think of home charging, and it runs on 240 volts — the same class of supply as an electric range or a dryer. That's not a bigger version of the same thing; it's a new circuit, a new breaker, and in many homes a new conversation about whether the electrical service can carry it. The DOE's guidance on the same page is direct about who does that work: "A qualified electrician can add circuits to accommodate the capacity needed for Level 2 charging," and it recommends a certified electrical contractor, noting that electricians can tell homeowners whether their home has adequate electrical capacity. You can read the department's overview on the AFDC home charging page.
The capacity question comes before the charger question
The instinct is to pick a charger first and figure out installation second. It works better in the other order, because the answer to "which charger" often depends on what your house can actually spare. A Level 2 unit can draw anywhere from around 16 to 48 amps continuously, and that draw stacks on top of everything else the home already uses — heating and cooling, water heating, cooking, laundry, and the long tail of small loads that never turn off.
An electrician settles this with a load calculation: a structured accounting of the home's existing demand against the capacity of the service feeding it. Sometimes the result is comfortable, especially in a newer home with a 200-amp service and gas heat. Sometimes it's tight, and the honest recommendation is a smaller charger, or one that can be dialed down, rather than the biggest unit on the shelf. If you don't know what your service is rated for, the piece on how many amps your home actually has is a good place to start.
A dedicated 240-volt circuit, sized for continuous duty
Vehicle charging gets its own article in the National Electrical Code — Article 625 — and one detail there shapes the whole installation: charging equipment is treated as a continuous load. Most things you plug in run in bursts. A car charges at close to full draw for hours at a stretch, which is a meaningfully harder job for a conductor and a breaker. The code's response is to require the circuit be sized above the equipment's rated current rather than exactly to it, which is why a 40-amp charger lands on a 50-amp circuit rather than a 40-amp one.
That rule is why "there's already a 240-volt outlet in the garage" isn't the shortcut it looks like. A dryer or welder receptacle was sized for a different duty cycle, on wiring that may be fine for occasional use and marginal for four hours of steady draw. Whether it can be reused takes knowing the conductor size, the breaker, the run length, and what else shares the circuit — exactly what you can't read off the faceplate.
Where the panel becomes the bottleneck
Even when the service has capacity on paper, the panel can run out of physical room. A Level 2 charger needs two adjacent slots for a double-pole breaker, and a lot of panels simply don't have two adjacent slots left. From there the options branch: a subpanel to gain space, a load-management device that lets the charger and another large appliance share capacity by never running at full draw simultaneously, or a full service upgrade if the calculation says the home is genuinely at its ceiling.
Those are different jobs at very different prices, and which one you need comes from the calculation rather than preference. It's also why quotes for the "same" installation vary by thousands of dollars between two houses on one street. If a quote arrives without anyone opening your panel or asking what else runs in your home, that's a quote for a generic house.
Permits and inspection come with the job
A new 240-volt circuit is permit work in essentially every jurisdiction, and charging installations get their own attention from inspectors because the load profile is unusual and the equipment is newer than most of what's in the walls. The DOE's guidance reflects this too, stating that a site installation plan must be submitted to the permitting authority for approval before installation, and pointing homeowners to their local building authority for specific requirements.
In practice an electrician handles this as ordinary paperwork — pull the permit, do the work, meet the inspector. What you should notice is a contractor who proposes skipping it. Unpermitted work on a circuit this size surfaces during a home sale or an insurance claim, long after the savings are forgotten.
The shortcuts worth refusing
A few specific ideas come up often enough to name, and each one is a genuine hazard rather than a technicality.
- Extension cords. No charging setup should involve one, at either level. A cord not rated for hours of continuous current is a heat problem waiting for the right night.
- Unlisted equipment and adapters. Charging hardware should be listed by a nationally recognized testing laboratory. Off-brand adapters that convert one plug type to another are a common source of melted connectors.
- Sharing the circuit. Charging belongs on a dedicated circuit with nothing else on it — not the freezer, not the garage outlets.
- Reusing an old receptacle on assumption. An existing 240-volt outlet may be fine, and it may not be. That determination is a measurement, not a guess.
- Charging through a damaged cord. Look at the cable and connector before each use, and stop using anything cracked, discolored, or warm at the plug.
What to line up before the first quote
You can save a visit's worth of back-and-forth by gathering a few things in advance: the amperage on your main breaker, a photo of the open panel door showing the breakers and the manufacturer's label, the make and model of the car, the charger you're considering if you've picked one, roughly where in the garage or driveway you want it mounted, and a list of the large appliances in the house — electric range, dryer, water heater, air conditioning, heat pump. None of it requires touching wiring or removing a cover, and it lets an electrician give you a real number instead of a range.
The practical order of operations
The sequence that avoids wasted money is straightforward: call your utility about rates and rebates, have a licensed electrician run a load calculation and look at your panel, then choose a charger that fits the answer, then let them pull the permit and do the install. Buying the hardware first is how people end up with a 48-amp charger in a house that can comfortably support 24, or a wall unit sitting in a box for two months while a service upgrade gets scheduled. The car is the easy part of this project. The house is the part worth asking a professional about first.