How to Charge Your Electric Vehicle Using a Portable Generator

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.

Alexey P. , Qualified Electrician and Website Founder
Alexey P. , Qualified Electrician and Website Founder

My name is Alexey P. I was born in Poland but later moved to the USA in 1998. As a well-qualified and fairly experienced electrician, I love working with DIY projects. As a result of my professional training in the field of electrical engineering, I am well versed with the key elements of the trade. I am generally knowledgeable with all inspecting codes and important regulations governing electrical components and repair. I presently live in Dover, Delaware, USA. Want to know a little about my life outside work? It is no wonder. If you encounter any challenges with your portable generator while on that camping expedition, you can count on me to help deal with that decisively. I love life. I love people. And yes, I love generators, of course!

  1. 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??

    • 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!

  2. 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

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

  4. What about electric generators are they strong enough

  5. 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!

  6. 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

  7. 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.

  8. 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?

  9. 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

  10. 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?

  11. 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.

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