How to Charge Your Electric Vehicle Using a Portable Generator

Last Updated on July 5, 2022

Can a portable generator really charge an electric vehicle? This seems to be an awkward question.

Happily, the answer is yes! Nevertheless, some cautionary steps are in order. As noted, some might find it ridiculous that anyone can suggest using a portable generator to charge a motor vehicle.

It Works During Emergency

However, why do most people buy electric vehicles? Often, it is because they want to save on using gas. However, life is often not always about what we want. Unexpected situations arise. We use generators to serve as backup power source in case of power outages. These outages can occur and affect you while traveling to a remote area or camping faraway. It can be safe and effective, in such circumstances, to charge your car using a generator if you are knowledgeable about how to do it correctly.

We will now tell you all that you should know about using a portable generator to charge an electric vehicle. The first point to note is that you cannot use any kind of generator and expect to charge your car successfully.

Factors to consider when choosing a Suitable generator for EV charging

The generator you choose must have a clean output of sine wave. For this to happen, you need an inverter generator. Some vehicles like the Tesla can easily tell when the output produced is not pure clean sine wave. In such a situation, it just refuses to charge. This safety mechanism is important because a power surge can be quite damaging to the car. For this reason, such vehicles as the Tesla will only charge when the power is stable.

Remember that, theoretically, all inverter generators offer pure sine wave. The reality, however, is far from that. For instance, some inverters have a sine wave that is modified. It can be a modified square wave or a simple square wave. The Tesla car, that we are using as an example, will automatically consider this sine wave as dirty energy and, therefore, will fail to charge. For this reason, always insist on an inverter with pure sine wave effect. Note also that most relatively cheaper generators usually offer modified sine wave rather than pure sine wave.

How to Charge Your Electric Car with a Portable Generator

You have now determined that you have an inverter generator with stable energy and clean pure sine wave. It is ready. You have checked the grounding and found that it is all right. Now, you need to know exactly how to charge your electric vehicle using the generator.

The first thing you should be aware of is the amount of charge needed. Always start with the lowest possible charge rate. Gradually adjust this to about 28-30amps. This is good because it prevents overloading and protects the motor. Remember to adjust the amperage down before you try plugging in the generator.

General Guidelines on Charging Electric Vehicles Using a Generator

Apart from the Tesla car that has been used as example, some other vehicle models can also be charged using a generator.  These include the Chevy Volt and the Nissan Leaf. Both of these can be charged fast using a gas powered generator. While doing these, use the same caveats regarding appropriate sine wave inverter, proper grounding and the right amperage adjustments.

Extra Notable Factors

You need to know that charging an electric vehicle using a portable generator can be a slow and lengthy affair. Good enough, this kind of activity is not usually an everyday activity. It only applies in emergency times. For this reason, you don’t really need to have the car fully charged.

Using a 4000W generator, it will take you 24 hours to fully charge the vehicle. This can mean using several tanks of gas. It is generally practical to use just about one gas tank to charge the vehicle to reasonable power levels rather than do this for a whole day.

Don’t Charge on the Road

If you use a Generac IQ2000 generator, you should be able to get about 12-18 miles per gallon, measuring gasoline value. Can you, however, use the generator while on the road in order to extend the drive time? This might be enticing. It is, however, not safe.

When driving a vehicle like the Tesla, cited above, this would be a breach of warranty since the manufacturers explicitly warn against charging the car using a generator. Otherwise, you would have to make some huge modifications to the car. Both of these options are neither viable nor advisable.

Remember that every generator needs regular maintenance. Unless you do this, the machine will refuse to start the next time you need to use it. If you purchase a generator simply to charge your car, it is likely to have maintenance issues since emergencies do not occur every day. It can take long before you use the generator. This can lead to possible problems when starting the machine in future.

Generac IQ2000 Generator – A Powerful Beast to Charge Your Car

One of the most highly recommended generators for charging electric cars is the Generac IQ2000 generator. Apart from being one of the quietest in the market, it has   good gas consumption rating and powerful capacity. It has a rating of 3.3 amps at 120 volts. It has a maximum AC output of 2000w starting and a fuel capacity of 1.06 gallon.  It can run for 9 continuous hours on this fuel, carrying a load of 500w. Using it, you are able to power multiple devices beside the exciting ability to successfully charge your electric car when necessary.

Portable Generators with the Right Sine Wave Output

The following generator models are guaranteed to offer a pure sine wave output:

Note that it is important to ground the generator while charging your car or vehicle. In most cases, the generator frame usually provides adequate grounding for the machine. The inbuilt charging system for some cars like the Tesla are capable of sensing that the generator is not properly grounded. Again, in such cases, it simply refuses to charge.

You will find most Honda generators behaving similarly. You can solve such issues by using an adapter plug to bridge the ground and the neutral with resister. For certain generators, you may have to literally ground the generator before commencing the charging. You can easily do this using a metal rod driven into the earth and connected appropriately. Use a generator with fair wattage amount. This means about 1500 watts at the least. Do not use a small generator since it is less powerful and will likely not charge the car successfully.

Final Thoughts

All factors considered, a portable generator can offer a cheap and reliable means of backup power supply during times of need. It can help to power your electric vehicle when necessary. For this reason, it is advisable to carry a generator and a little gas whenever you go out on a road trip or some far away camping expedition.

While at home, keep a generator and some gas handy in preparation for the inevitable power outage at some point or the other. Definitely, if you make sure to use an inverter generator with a pure sine wave and appropriate means of grounding, you will be able to charge your electric vehicle successfully, without hassle.

The most highly recommended generator for this activity is the Generac iQ2000. This is because it offers great pure sine wave, contains a built-in bridge for ground neutralization purposes and is relatively affordable when compared to most of its peers.


Join the discussion and tell us your opinion.

June 4, 2019 at 8:18 pm

Why not have an outside source that could be applied such as a small wheel connected to a generator that would drop down once the car is moving at full speed independent of the existing motor to recharge it as it speeds along, almost the same way that large airplanes have an emergency propeller that drops down if engine power is lost to maintain power to the instruments and hydraulics??

December 15, 2020 at 8:18 pm
– In reply to: LAURIER

Actually, you probably do have this already… its called reGENERATIVE braking. Capturing a portion of your energy back as you break. But the system is also working while you drive and if you let off the accelerator, you should see some level of charging occurring. You never get back as much as you spent getting up to speed, but every bit helps!

September 28, 2019 at 8:19 pm

I drive a Kia Soul EV – I’m looking more at a Battery powered generator , I can charge my car for free off a huge solar panel and charge my backup battery generator off it , if I had one, and then connect a solar panel to the battery generator , for camping and long distance road trips , this would be amazing

Thinking about the YETI 3000W

September 18, 2022 at 8:50 pm

The car’s battery is 64 kWh. The Yeti 3000 capacity is 3kWh. – So you’re planning to fill up your luggage space with an extra battery to be able to drive another 10, maybe 15 miles rather than keeping an eye on your charge and taking on board another 250 mi by charging the car’s own battery. – I don’t really get this idea – I guess it’s a bit like carrying spare fuel in a can for one of those obsolete internal combustion engines that grandpa’s generation used to drive, though a lot less dangerous.

November 14, 2019 at 8:19 pm

I agree to the comments above . Someone i know say. that way only for the people live out is space made it’s.

FRANK P.reply
November 21, 2019 at 8:20 pm

What about electric generators are they strong enough

December 15, 2019 at 8:20 pm

Loved the article. I own 2 vehicles, one is a plug in hybrid, and the other is pure electric, that pertain to this article. In regards to WHY you would want to do this? I can tell you that fast, reliable chargers are coming online with increasing regularity, but… they are not always working! My wife and I travel all over Florida in a 2019 Leaf, which accepts a DC fast charge or AC charging with the J1772 connector you show in the photo. We routinely arrive at a ChadEmo equipped charger (30 – 60 minute charge) and find they are not in service, despite what the “app” says. Sometimes we find this out past “the point of no return”, and scramble to find power solutions along our path. Driving electric today is an excercise in PLANNING

Obviously the DC charge is not going to happen from a store bought generator, but the A/C charge should be doable. Our home charger is A/C, 240V and runs about 32 Amps. That seems doable on many generators I have seen… but now I know I need an Inverter/Generator with a pure sine wave output. Thanks so much!

October 29, 2020 at 8:21 pm

I have a 3500W peak power out generator without inverter , can i use this generator for leaf car charging. manufacturer said that it could be used to Power computers TVs and many sophisticated electronic gives exactly 50Hz 230V ac power but sine wave output is not confirmed git has 12V DC output for battery charging i use this 12V DC out put with 2500-5000W watts separate pure sine wave inverter to charge nissan leaf please reply to [email protected]
Jayantha Perera

January 10, 2021 at 8:21 pm

I’ve tried a van mounted inverter and a 6.5kva generator today in an attempt to charge a Nissan Leaf that ran out of charge about 1/2 mile from my home. In both cases the charging unit recorded a fault code ‘not grounded’ and refused to charge. I had asked the hire shop specifically about what model generator I needed to ensure grounding, and used the one they recommended. So not at all that easy to do. No generator that I asked about had a grounding spike as an accessory.

J PRICEreply
February 9, 2021 at 8:21 pm

Why does an EV need a ground in order to charge? The car sits on rubber tires. Can you just ground the chassis to neutral?

July 15, 2022 at 5:58 pm
– In reply to: J PRICE

Exactly because of what you say. On any fault the electronics need to discharge to ground. EV are equiped to charge a 240v, in US, those are 2x120v lives together (no neutral). is ground is a MUST for this circuit. If something fails the care is insolated and is more provable to catch fire or discharge to a person that is touching the car and touching the ground. that’s why ground is a MUST. and glad that cars wont charge without it, or a lot of people would get shock every time that they touch the car and convert themselves in a ground

May 11, 2021 at 8:22 pm

I have an electric golf cart with a 2000 Honda generator in the storage compartment in the back if I get stuck I can stop and he charges a fine is there anyway that I can actually let it charge as I drive down the road
Right now it will not allow me to do that because when it’s plugged in it will not move

I’m sure that is a safeguard so that you don’t drive away with the cord still in the car

July 15, 2022 at 6:01 pm
– In reply to: JIM SWINGLEY

Yes, the car not moving while charging is a “security feature” that is actually there ver compliance (all cars must have that). Specially since you put it to charge and leave it over the night or long periods so is easy to forget it. Imagine people still drive off from a gas pump still connected to it, and it was like 5 minutes… Still some people flashed the firmware and disabled this. or just installed a secondary charge controller on the side. There’s a guy with a rav4 in NYC, that put a trailer with a tesla battery pack behind and he is driving and charging at the same time. He has like 400 miles range on an hybrid rav4 😀

June 8, 2022 at 8:22 pm

I was wandering if anyone made emergency generator with charging circuit and plug to specific cars to be more efficient than the plug in chargers that come with the car?

July 15, 2022 at 6:03 pm
– In reply to: ONICK

Well if source is gas would be never more efficient. What already exist are “portable” carts with batteries banks that will charge at level 2, or even DC Fast charge (level 3). So you can have this secondary pack and charge your car in emergencies. (some mobile tesla mechanics has them) Imagine that electric cars are simpler with less moving parts than an internal combustion cars. So, again add an engine, a gas tank, etc. is just complicating things, adding weight and price to the car. At that point just sell your car and get another electric with better range like kia, or a charging grid like tesla.

June 16, 2022 at 8:22 pm

A true test of the practicality of EVs will be the first hurricane evacuation with an accurate collection of EV performance and issues data. I suspect EV salespeople don’t want to know the truth; so, I’m not holding my breath.

July 15, 2022 at 6:07 pm
– In reply to: TERRY KELLNER

I lived in florida until last year. and I owned a chevy Bolt. The first thing that you dont have during a hurricane (not even a real one, just an advisory), is gas. the gas is gone because all people fill up their tanks. So, you still can keep using your car and topping off the battery until the “posible” power shortage. I felt way more safe having an electric car than a gas car every time that a hurricane alert came. In any case I have a propane generator. Propane is way easier to keep finding during the worst hurricane escenario. Easy to store. Y could have 4 propane bbq tanks stored like forever, for the cost of 100U$. and those 4 propane tanks are 40 hours of electricity. Your fears are way wrong 😀

Chris Zreply
July 26, 2022 at 1:21 pm
– In reply to: deftoner

From what I’ve heard the Propane generator is a much better idea than a gas generator. I understand it is cleaner and quieter as well. Can you give a little insite into this as far as power output compared to gas, emissions etc? I’ve also seen that there are companies creating solar tano (sp) covers for the pickup trucks when they come out. Sounds like people are thinking for the solutions already, which is good.

George Masterreply
August 15, 2022 at 3:30 pm

Called my Generac dealer about the grounding of the IQ2000 and was told that it does not have a ground to earth setup but GFI outlets. Do you think this will satisfy the grounding requirement for charging an EV?

Hunter Greply
September 1, 2022 at 2:22 pm

I own a EV and I can’t wait until all cars are mandatory electric. I wish there was a company that would install the generator right into the engine so my EV could run directly on gasoline. It seems like a better solution until they can make the grid more reliable.

John Parkerreply
September 7, 2022 at 12:36 am

I was thinking more along the lines of a roof rack, and solar panels mounted flat to minimize wind resistance, get a continuous level one charge during the day, as well as providing shade for the passenger compartment reducing AC demand; but it sounds like the charging circuit will not allow even level one charging while in motion. Any hacks or would the grounding issue make that unsafe? I’d buy it if priced reasonably and made as a package. Maybe anti-static style grounding straps that hang down and contact the road when vehicle is stopped would help?

George franzreply
November 23, 2022 at 10:03 pm

I’m looking at a generator on my land in far east Texas. Ican make the drop from dfw only one way, and the only working charging station near the land is in texarkana, 35 miles away (70 round trip) from the land. But if I could get to my land and then add about 100 miles to my charge, I could make the round trip without taking a 70 mile detour (plus charging time) in a Ford Lightning. I already have 3 generators of different sizes and a tiny solar setup. I just want to be able to top off when I get there so I can safely make the trip back without huge detours. I need some way to slow charge at 1 to 4 kw for 15-20 hours. It’s too bad about using gas, but I only make the trip monthly, and the only other option for a truck is ICE or a hybrid. I got the 2021 ford hybrid just because I can’t make it there and back in a lightning. In the hybrid I can go 650 miles on a tank, there and back easily, if more expensively.

December 4, 2022 at 4:26 pm

Stick to proven and now almost perfect petrol cars and just carry a spare can of fuel in the boot. Sorted!

December 10, 2022 at 8:13 pm

That is why the volt was a perfect EV

Dana Parkhurstreply
February 24, 2023 at 12:41 am

I say that the best resolution is a hybrid vehicle that if there is no gas you can make it to gas off the electric charge and it’s electric charges dead you still have the gas to run. I do agree with any hybrid vehicles heading solar panels to all the flat surfaces such as the front hood rear deck and the roof. I rented a Kia hybrid SUV and achieved 48 miles a gallon average from New York to North Carolina 630 miles each way. I had a Ford festiva which got 45 miles to gallon by itself and contemplated trying to turn it into a hybrid because I thought I could get maybe 80 miles a gallon with that.

Robbie Robinsonreply
March 8, 2023 at 12:03 am

George Franz, hello fellow Texan! To help answer your question, if you got the battery generator EcoFlow which “should” charge an EV as stated, and paired it with solar from a roof rack perspective, you could increase your range when you stopped to do your business.

I have been looking at a similar setup so that I can charge my car during the working day since I drive 100 miles round trip.

March 9, 2023 at 2:31 am

i tried charging a newer prime and a 2014 leaf with a well grounded honda 2000inverter. neither worked. vehicles would not recognize inverted generation as good power. generac inverter is a cheap version of a honda/yamaha…same as hyundai/champion/ insert any brand cheap gin joint knockoff/, and any inverted power is an artificial wave, so EV’s have trouble with them( although there is a trick to tie neg to ground, but i am not doing that with a $50000 car) A QUALITY old-school motor generator by honda/yamaha/onan, even generac, actually produces a natural sinewave by rotation and may well do BETTER than an inverter. Also they are steel frame grounded. I would like to hear if anyone has made the old genny work as a charger

Frank Hughesreply
April 5, 2023 at 8:20 am

Small and large vans have condensors on the roofs for the refrigeration units with 2 fans to cool the unit , if two generators were connected using fans the wind drives the fans so the batteries are being charged whilst driving ,or a solar panel as part of the roof

May 29, 2023 at 5:37 pm

Stick to a good old, proven technology, petrol engine and keep a spare gallon of gas in the cars trunk!

Joseph khalo.reply
September 14, 2023 at 8:12 am

Hello EV Fellows,i do drive an OUTLANDER EV and the car covers
150kms with about 50-60kw/h on daily basis.
But when on work,i wll make sure my EV get charged with our companies power whch usually take 5-8 hrs of charging.
I encourage all u guyz wth EV to do that with alternate charger from your advanced technician.

Leave a reply