Can You Charge an Electric Car With a Generator?

How Do Electric Cars Charge, and How Does That Affect Charging with a Generator?

Your car’s battery charges using DC power. When you connect your car to AC power, it uses an on-board rectifier to turn that power into direct current electricity. A fast charger has its own rectifier, turning AC power from the grid into DC power, which goes directly to your car’s battery.
 
The charging socket on your car has three sets of pins: AC power, DC power and signal pins. The signal pins let the charger and car communicate with each other. This lets the car control how much electricity it’s getting, so it can get the best charge rate for the battery. However, since all the hardware for AC charging is built into the car, it can manage charging rates by itself.
 
There are three types of charging plugs used on modern electric cars:
 
SAE J1772
Nearly all electric vehicles aside from Teslas use this plug standard. AC charging uses a round plug that connects to the AC and signal pins. A larger plug connects to these pins and the CSS pins below them for DC charging.
 
Tesla 
Tesla introduced their cars before the J1772 standard, so they had to develop their own charging system. Tesla’s connector puts the DC, AC and signal pins into one plug. Teslas can connect to J1772 and CSS connections with an adapter.
 
CHAdeMO
This Japanese standard was used on the Nissan Leaf until 2021, the Kia Soul EV until 2020, and all model years of the Mitsubishi Outlander PHEV. Its plug design is similar to Tesla’s, placing all the pins in one socket. However, unlike Tesla and SAE chargers, CHAdeMO uses the car as the ground, not the charger. This makes it incompatible with other charging systems, so you need to use adapters made specifically for CHAdeMO to connect it to a generator.
 
Since CHAdeMO cars have their own ground, you can connect them to a generator using an adapter. Both SAE and Tesla charging systems ground through the plug, so you need to add an external ground to your generator. Most 2,000 watt and larger generators have a grounding lug you can connect to an external grounding rod. This rod is pounded into the ground like a tent stake.

Do You Really Need to Charge Your Electric Car with a Generator?

With America’s DC fast charger network expanding to meet new demand, car reviewers focus on using them for road trips when they review electric cars. This may give you the impression that most of your charging will be done at these stations, and you’ll always be worrying about access, station breakdowns and long charging times.

However, the vast majority of EV owners do almost all of their charging at home. A Level 2 charger adds between 10 and 30 miles of range every hour, so you’re pretty much guaranteed to get a full charge between coming home from work and leaving the next morning. A Level 1 charger, which plugs into a regular household outlet, adds between 3-5 miles of range every hour. If you drive less than 40 miles per day, that’s more than enough to keep your battery topped up.
 
Although early EVs had ranges as low as 60 miles, new models have ranges between 200 and 400 miles. If you’re without power, you still have several days worth of range to get to work and run errands.
 
You may not even need a generator for home backup power if you have an EV. With new two-way charger systems, you can use your car’s battery to power your home. These use the vehicle’s DC connectors to send power from the battery to an inverter built into charger, then out to the rest of the house. For example, if you have an Intelligent Backup Power station and a Ford F-150 Lightning, you can power an average home for up to three days.
 
If you’ve been in a natural disaster before, you know electricity is restored on major roads first, so stores can reopen. That way, people can get the supplies they need. Fast charging stations are attached to gas stations, large stores and shopping areas, so they’re one of the first places to get power. It’s unlikely that you’ll be without power long enough that you’ll need to use a generator to charge your car.
 
With this in mind, here are some situations where you could use a generator to power your electric car
 
Solar power : You may not be ready to invest in a home solar setup, but you might be able to add a few miles of range to your car by plugging it into a solar generator.
 
Emergency power storage : Already using a generator for backup power? What if you also charge your car, then use it to power your appliances at night? That way, you don’t have to worry about your generator shutting down or running out of gas while you sleep.
 
Losing power in a remote area : What if you manage to run out of power far from any source of electricity? You can use a generator to add a few miles of range, so you can drive to the nearest plug.

How Fast Can I Charge My Car?

Since generators don’t have signal pins to communicate with your car, you will need to set the charging speed manually. Your car’s infotainment system should display charging options once you connect it to the generator. Check your owner’s manual for more details.
 
When you set the charging speed, you need to keep it from overloading the generator. Generators are rated in watts, while your car chooses its recharge rate in kilowatts (kW.) One kW is equal to 1,000 watts.

The amount of power you can draw depends on several factors:

Which Connection Works Best for Charging My Car?

NEMA connectors are rated in amps. There are four types of NEMA connectors you’ll find on generators: 5-20, L5-30, TT-30 and 14-50. Sometimes, you’ll see these codes with an “R” or a “P” at the end. “R” identifies sockets, while “P” is used for plugs.
 
5-15 is the standard three prong socket used for home power outlets. This socket supports up to 15 amps. That’s equivalent to 1,875 watts or 1.8 kW. Most 120 volt outlets on generators use the 5-20 standard. This is compatible with both 5-15 and 5-20 plugs. 5-20 supports up to 20 amps. That’s equal to 2,500 watts or 2.5 kW.
 
L5-30 and TT-30 are 120 volt RV shore power sockets. They support 30 amps of power. That’s a maximum of 3,250 watts or over 3 kW.
 
14-50 sockets are used for RV shore power and clothes dryers. They support up to 50 amps. That’s equivalent to 6,250 watts, or just over 6 kW. This socket supports both 120 and 240 volt power. Generators only make single phase power, while household 240 volt outlets provide three-phase power.  However, since this AC power is converted into DC power to charge the battery, the phases don’t matter. You can use 240 volt mode if your car and adapter support it, or you can get the same amount of electricity in 120 volt mode.

Frequently Asked Questions

Can You Charge an Electric Car With a Solar Generator/Power Station?

Yes. A solar generator has a battery that charges from a wall outlet or solar panels, and circuitry that converts that power into different forms for appliances. As far as your car is concerned, there’s no difference between plugging into a solar generator outlet or a home outlet.
 
Keep in mind that power generation is going to be the biggest limiting factor. If you have a pair of 100 watt solar panels, you’re only going to make about one kWh of electricity on a sunny day. You can be ready for emergencies by charging your generator ahead of time.

Do You Need to Use an Inverter Generator to Charge an Electric Car?

No. Alternating current constantly switches polarity. An inverter generator uses circuitry to smooth out this switch, so this power is the same as what you get from the grid. Inverter generators are a must for electronics. However, since your car converts AC power into DC, it removes the electrical interference you get from standard generators. That means you can use either an inverter or standard generator to charge your car.

Is a Generator a Good Charging Option if You Live in an Apartment?

For most apartment dwellers, the easiest way to charge is with a DC fast charger. Charging with a gas or diesel generator is really inefficient, and it may violate noise ordinances. However, if you have access to street parking, you might be able to set up a solar generation system to add a few miles of range each day. If you work from home or use public transit, and only drive a couple times per week, this could cover most of your charging needs.

How Long Does it Take to Charge an Electric Car with a Generator?

Range recovery varies depending on the type of electric vehicle you drive, in the same way fuel efficiency varies between bigger and smaller vehicles. You’ll get a lot more range from a small car than a large truck or SUV. Your car should be able to tell you your average miles per kilowatt hour. From there, you can figure out how many miles of range you’ll get from each hour of charging from your generator. Expect to get 3-5 miles of range per hour using a standard household connection, and up to 10 miles of range for every hour charging from RV connections.

Can You Charge an Electric Car with a Generator While Driving?

No. Obviously, you don't want to drive around with a running generator and a power cord dangling between it and your car’s power outlet. Even if you figure out a safe way to run and transport your generator, it still won't work. Electric cars are designed to cut power to the motor while charging. This keeps owners from driving off while the power cord is still connected.

Can You Charge an Electric Car With an RV Generator?

Yes. If you’re familiar with charging options, you know you can get adapters that let you use shore power connections at RV parks. These same sockets are included with most generators that have an output over 2,000 watts.

Can You Charge an Electric Car with a Diesel Generator?

Yes. It doesn’t matter what the generator is using for fuel. The power coming out of the generator is going to be the same.