EV Chargers: Everything You Need To Know

Here's what you want to look for in an EV charger, in descending order of importance for the average buyer.

Safety first

EV chargers are generally safe, but ensure the model you have in mind is UL-certified (an industry-standard mark of safety based on third-party testing by Underwriters Laboratories). As long as it’s UL-certified and you use it as directed, the charger is unlikely to cause a fire. All the models mentioned above are UL-listed, but some lower-cost models sold through Amazon are not.

Outlet vs. hardwire

Some EV chargers use a hardwired electrical connection – no plug, no outlet. Others plug into an outlet. For L2 chargers, that's typically a 4-prong, NEMA 14-50 outlet, like many electric stoves or clothes dryers. A lot of models come in both types.

Either type is valid, and it's a matter of personal preference. Here's what to know about each style:

Hardwired

• It's a cleaner-looking installation with shorter cable runs, no visible plug, and no outlet.

• You can avoid installing a bulky outdoor-rated outlet because the hidden electrical connection already makes the charger more weatherproof.

• Hardwired connections can charge faster than plug-in chargers (if your car and electrical wiring can support it).

• You'll need an electrician to install it, then uninstall and replace it when it wears out (though this shouldn’t happen for 5-10 years), so the costs can add up over time. 

Plug-in

• If you already have an outlet, you don't need to hire an electrician. Even if you need a new outlet, or your outlet wears out, you won't need an electrician to swap out chargers in the future, which saves you money in the long run.

• Certain models are weatherproof (for outdoor use), though you'll need to plug into an outdoor-rated outlet.

• They have a maximum charging speed of 40 amps (20-30 miles of range per hour). That's the safe limit for a NEMA 14-50 outlet.

Connector type: Tesla vs. everything else

In North America, EV chargers come with one of two connectors for at-home use: 

• A Tesla connector shaped for the port on a Tesla.

• A J1772 connector, shaped for the port on literally every other make and model of EV.

It makes some sense to get a charger with a connector that matches your car's port, but it doesn't actually matter because they're cross-compatible. Adapters to get a Tesla EV to work with a J1772 charger cost about $50. Adapters to plug a J1772 vehicle into a Tesla charger are about $150. 

Cord length

We've all pulled up to the gas pump on the wrong side, and we'll all end up parking our EVs too far from the charger at least once. You probably won't regret having the extra length of a longer cable.

According to the National Electrical Code, the maximum safe cable length is 25 feet. Most Level 2 chargers are at least 20 feet long. Aim for something in that range. 

Technically speaking, longer cords could be less energy efficient than shorter ones. More energy can get wasted traveling along the longer wire, but real-world testing by Car & Driver didn’t find any meaningful difference from model to model.

Scheduling

EVs draw a lot of electricity. If you can find ways to pay less for electricity, you can save a lot of money over time. Solar power is an excellent way to save (and EnergySage can help you get quotes for rooftop or community solar). You could also look into discounted rates from your utility company.

More than 60% of households in the US are eligible for discounted electricity at certain times of day, according to the Energy Information Administration. Utility companies usually call these programs "time-of-use" or "dynamic pricing" plans. 

If you sign up for one of these plans and do most of your EV charging when power is relatively cheap (usually overnight), you can save a ton of money.

An EV charger with a scheduling feature (via mobile app) can help you take advantage of those discounts. You can physically plug in the car whenever it's convenient, but it won't start charging until a time that you've specified in the app. You can always override the schedule if you need to start charging immediately.

Some lower-end chargers have a timer rather than a scheduling feature. You'll set it on a basic LED interface built into the power "brick" on the cord. It's not elegant, but it works.

Other notable features

An app: Most L2 charging stations can connect to Wi-Fi and have some sort of mobile app. It's where you'll set charging schedules (see above), adjust the power output (see below), monitor the charging status, and track your energy use over time. They all basically do the same thing, but some are better looking, others more prone to glitches, and a few try to shoehorn in an extra interface for public charging networks, too. If you think this will be something that matters to you, check the app store ratings before buying.

Output control: This lets you control the charging rate. If you own a 32-amp charger, you can usually set it to supply just 24 amps, 16 amps, or even 8 amps to your car. Why would you do this? Maybe you're trying to manually manage your home's electrical load to avoid tripping an underpowered breaker, or you’re acting out of some sense of courtesy for the electrical grid. 

You never really need to do this. The EV itself will only ever draw as much power as its battery can safely handle, and there's no good evidence that L2 charging is any worse for an EV battery's longevity than L1 charging. Still, most L2 chargers provide this option if you want it, though not all of them.

Demand response: Certain EV chargers are also compatible with demand response programs through your utility company. If you opt-in, it gives the utility some control over your charger (via software), typically in exchange for a small cash rebate. 

Demand response typically works like this: The utility can turn off or turn down an EV charger at peak demand to help avoid overloading the grid. That might be during the early evening on the hottest days of the year, as people arrive home from work and crank the AC or frigid winter mornings in regions with a lot of electric heat. All the demand response programs we know of allow you to override the utility company's control, but you might lose out on the rewards.

Overall, there are a few other things to keep in mind. One, you’ll rarely charge your battery from completely empty to completely full. EV drivers are far more likely to “top off” their battery—making charging times quicker in practice. (In general, most manufacturers suggest keeping the battery’s charge in the range of 20 to 80 percent to extend its life.)

And, of course, not every car has the same battery capacity. General Motors’ 2022 all-electric Hummer, with its massive 212 kWh battery, could take hours longer to fully charge than the Chevy Bolt’s more modest 65-kWh battery. That said, Level 2 charging can generally charge even the biggest EV batteries overnight.

Additionally, not every battery can accept electricity at the same rate, a limitation that’s most relevant when it comes to Level 3 charging. The first generation of EVs was often only capable of charging at 50kW, so they cannot take advantage of the 350kW Level 3 charging stations that are increasingly the industry standard and which can provide hundreds of miles of range in about as much time as it takes to get a coffee and use the restroom.

What are the different types of EV plugs?

EVs have distinct charge ports, which are like outlets on the car. This means that the shape of the plug you connect to your EV varies as well. It’s important to know what plug your car uses, as not every public charging station will be compatible with every kind of plug.

For Level 1 and Level 2 charging, all EVs sold in the United States (besides Teslas) use a J1772 plug (also known as a J-plug). For speedy Level 3 DCFC, all U.S. EVs (again, besides Teslas) use either CCS (which stands for “combined charging system” and is the most common) or CHAdeMO plugs, depending on the brand of car. Teslas use the same proprietary plug for all levels of charging—including at Tesla Supercharger stations. They also come standard with a J1772 adapter.