Can I Charge my EV with a Portable Generator?

There are plenty of perks that come with owning an electric vehicle (EV). Depending on where you live and when you buy one, your purchase can come with tax credits and other incentives. And since EVs don’t use as many of the fluids that gasoline-powered vehicles do—like motor oil—you won’t have as many recurring maintenance items to worry about.

One recurring item you will need to take care of, however, is charging your EV’s battery—which is a little more complicated than some people expect.

So how does charging an EV work, and how long does it take to do so? In a power outage, is charging an EV with a portable generator possible? Better yet, is it worth purchasing a portable generator for this reason? 

Today, we’re answering these questions in detail.

How to Charge an EV

Whether you’re at home or in the middle of a road trip, there are a few different ways to charge your electric vehicle.

These methods are generally categorized under three main levels. The first two levels mostly apply to charging your EV at home, while the third level applies to high-speed EV charging stations you’ll encounter on the road. To extend this dialogue, let’s review these categories.

Level 1: 120 Volts

When you purchase an EV, it will almost always come with a “Level 1” charging cord. It makes use of alternating current (AC) and plugs into a standard, 120-volt home outlet.

On one end, this charging cord will have a standard three-prong NEMA connector that plugs into a home outlet. At the other, there will be a connector that plugs into the EV’s charging port.

Level 1 charging cords are sometimes interchangeable, but not always. There are a number of different connector types that might be used, but the two main types are:

  • SAE J1772 connectors
  • Tesla connectors

Currently, the vast majority of EV manufacturers use the J1772 adapter for their vehicles.

The major exception to this is Tesla, which uses a connector type that’s only compatible with its own vehicles. Luckily, Tesla vehicles do come with J1772 adapters that you can use when you don’t have access to a Tesla charging cord.

Regardless of what kind of Level 1 charging cord you have, it’s important to keep it in your car when you’re not using it—this will give you more recharging options when you’re on the road.

How Long Does Level 1 Charging Take?

When recharging an EV from a standard home outlet, you could generally expect it to gain around 5 miles of range per hour.

An overnight Level 1 charge time could give you enough battery power for around 40 miles of range, depending on the vehicle. For many people’s purposes, this provides enough power to tackle the next day’s commute.

Level 2: 240 Volts

“Level 2” charging allows for faster EV charging speeds at home. In addition to your own home, you might find Level 2 charging equipment at public charging stations or in workplace parking lots. The Level 2 charging method is an especially appealing option for drivers who:

  • Have long commutes
  • Don’t have time for extended charging sessions between trips
  • Want added peace of mind if they need to leave for somewhere in a hurry

But it comes at an extra cost. That’s because Level 2 charging typically requires:

  • The purchase of additional equipment
  • An electrical upgrade

Level 2 charging equipment usually requires a 240-volt outlet—like what you’d use for a clothes dryer or another large appliance. If your garage doesn’t already have one, you’ll need an electrician to install one for you.

Installing a Level 2 charging setup in your garage doesn’t just double the voltage you're working with compared to a standard home outlet, it also provides more amperes (amps).

Depending on the capabilities of the equipment and the power source, a Level 2 charging setup could operate using anywhere from 30 to 80 amps, although around 30 amps will usually be more common in a residential setting (a standard home outlet, by comparison, typically provides about 15 amps).

How Long Does Level 2 Charging Take?

Just how fast Level 2 charging actually is for you will depend on the range of amps the charging equipment can handle and the capabilities of the charger inside your vehicle.

Depending on those capabilities, a Level 2 charging setup could potentially recharge your vehicle as fast as 25 miles of range or more per hour.

Level 3: DC Fast Charging

You’ll find the fastest charging speeds for an EV at public charging stations along interstates or other areas dense with traffic. As of 2021, more than 15% of public charging ports were DC fast chargers but expect to see even more of them in the years to come.

These charging stations utilize direct current (DC) for a charging speed that’s lightning fast when compared with Level 1 and 2 equipment.

Because of the difference in power, a DC fast charger requires different connectors.  The three main types of DC fast charging connectors are:

  • CCS connectors (also called the “SAE J1772 combo” connector)
  • CHAdeMO connectors
  • Tesla connectors

CCS connectors share the portion of the charging port that a Level 1 or 2 connector uses but makes use of a couple extra pins below it. CHAdeMO connectors, on the other hand, are usually a separate charging port found next to the Level 1 or 2 charging port.

No matter the charging level, Tesla’s unique connectors are conveniently the same across the board. However, if you needed to charge up at an EV charging station that only had CHAdeMO connectors, you’d need to buy an additional adapter.

How Long Does Level 3 Charging Take?

How long DC fast charging takes depends on the EV charger’s capabilities, but the bottom line is that it’s much faster. You could generally expect to add as much as 100 to 200 miles of range after just a half hour of charging—and in some cases, even more.

How Long Does It Take to Charge an Electric Vehicle?

Time for a quick recap. Now that you know how the main EV charging levels compare, here’s a comparison of how long each charging level can take, side by side:

  • Level 1 (120V) : 5 miles of range per hour
  • Level 2 (240V): 25 miles of range per hour
  • Level 3 (DC Fast Charging): 100 to 200 miles per half hour

If you’re not sure how long to charge your own EV to reach full battery power at various levels, you should be able to find out by checking your owner’s manual.

Can You Charge an EV with a Portable Generator?

Picture this: you’re at home in the middle of a power outage caused by a snowstorm. You don’t have a generator during your power outage, or know when your electricity will come back on, but you do know you’re still going to have to get to work on time in the morning (and your EV only had about 10 miles of range left when you returned home tonight).

Could you use a generator to recharge an EV in a situation like this? Yes, but whether it’s practical to do so depends on the circumstances. In some cases, you might be better off using your generator for other purposes. A generator should be part of your winter storm preparedness checklist.

Finding a Compatible Generator

The main challenge you’d be up against is compatibility.

While the majority of electric cars have fairly interchangeable charging cords, the technology in an EV’s onboard charger is often highly specific for its make and/or model, so there’s not a one-size-fits all recommendation for whether a portable generator will be capable of charging an EV.

If your generator and EV are compatible, most generators are going to give you Level 1 or 2 charging capabilities. That means it will likely still take a number of hours—and at least several gallons of fuel—to power your battery up to an acceptable range.

Before attempting to charge an EV with a portable generator, you should:

  • Review your owner’s manual for your EV’s specific charging requirements and special precautions
  • Review the features and capabilities of the generator you’re considering

With a stable output and the right amount of power, certain EVs could have no problem charging up with a portable generator, even if it does take a while.

If you’re already using a portable DuroMax home backup generator to power your home’s outlets, it’s possible one of those could be the one that charges your EV battery.

But again, make sure your portable generator and its setup are compatible with your EV before attempting to charge it. Connecting the wrong kind of generator to your charging port (or an improper setup) could damage the EV’s battery or other electrical components, and considering EV batteries alone cost thousands to replace, this is probably not a risk you’d want to take.

In some cases, it’s also possible that you could risk voiding your warranty by using a generator in an attempt to recharge your EV battery.

Keep the Lights On With Help From DuroMax

Whether you’re looking for a home backup generator to have in emergencies, a unit to power your RV for your next off-the-grid camping trip, or, in the right scenario, to add a little more range to your EV’s battery, DuroMax has a variety of generator options capable of meeting your needs.

Our industry-leading Dual Fuel generators can operate on either gasoline or propane, which offers additional flexibility when you need safe, reliable power the most.

Not sure what kind of generator you need? Not a problem. We have a quick and simple quiz to help you figure out just that. From there, you can browse our portable generator offerings to identify which generator is the best fit for protecting you and your family.

And if you’re wondering how long to charge an EV, we hope this quick primer provided the answers you were looking for.