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Can You Charge A Tesla With A Generator?

Can You Charge A Tesla With A Generator?

If you have a Tesla and also have a generator for your home or for camping, you may have started to ponder the possibility of using a generator to charge your Tesla. 

Doing so would give you a lot of flexibility on long trips with a lot of time and distance between charging stations.

But can it be done, can you safely charge your Tesla with a generator?

You can actually charge a Tesla with a generator. You’ll need the proper adapter, to ground your generator, and ensure that it can provide a clean, unmodified sine wave. Also, the generator must be warmed up first, and the amps set to the lowest setting possible through your Tesla’s dashboard monitor. 

Now that you know it can be done, let’s take a closer look at what’s involved in using a generator to charge your Tesla.

How Big of a Generator Do You Need to Charge a Tesla?

If you want to charge your Tesla up to 100% when it has almost no power left whatsoever, you will need a generator that has a minimum of 1500 watts of power. 

Anything less, you will likely be unable to get your vehicle charged sufficiently before your generator dies.

For most Tesla owners who want to use a generator to charge their car, a generator of at least 4000 watts of power is needed. 

But remember, the generator must be properly grounded, the Tesla must detect that it is properly grounded, and the generator must have a pure sine wave.

With all this in place, we’ve found you’ll still need to be prepared to wait a long time to get your Tesla up to 100% power.

In fact, even using a generator of 4000 watts power, it will take at least 24 hours to complete the process. 

Also, remember that your generator will need multiple tanks of gas along the way to keep it running, so consider the cost and convenience factors before using this method of charging your Tesla.

How Long Would it Take to Charge a Tesla with a Generator?

To answer the question of how long it takes to charge a Tesla using a generator, we need to examine the charging times when other methods are used. 

For example, let’s begin with using a standard 110V electrical outlet to charge a Tesla. 

Once the vehicle is plugged in, it will take about seven hours for the car to be completely charged.

Next, when a 220V outlet is used, the charging time is reduced by 50%, with most cars being at 100% capacity within slightly less than four hours. 

Should you opt to use a Supercharger site for your Tesla, we find this only takes 60-75 minutes to be ready to hit the road. 

Though a typical home or portable generator will work in most cases to charge a Tesla, the difference in charging times may not make this a viable option under normal circumstances. 

To begin with, the Tesla owner’s manual advises against using portable generators. 

Also, not all generators will work on your Tesla vehicle.

If an invalid power source is plugged into the car’s charging system, the vehicle will not allow this to work. 

To get a Tesla charged to maximum power, it will take most of if not an entire 24-hour cycle, and that assumes you will be using a generator operating at a minimum of 4000 watts of power. 

Can You Charge Any Electric Car with a Portable Generator?

The answer to this question is yes, but you must be willing to be very patient, use the right type of generator and accessories, and take the necessary precautions. 

Unfortunately, one of the biggest stumbling blocks in these situations is that most smaller generators don’t produce enough power to charge electric vehicles in a reasonable amount of time, while larger generators designed to power homes are often too big for the job. 

However, using a portable generator, even if it does take longer to get your Tesla charged, does offer some advantages. 

Along with the obvious one that charging stations are not as numerous as gas stations, they also make you self-sufficient should your power grid go down or if you want to live off the grid altogether. 

When using a portable generator, you should expect it to become louder and louder as the charging process continues. 

Since most portable generators are not specifically designed to charge electric vehicles, your generator will struggle to keep up with your car’s power demands. 

In many cases, generators may die trying to do so, which if this happens could have you out hundreds of dollars for a new generator. 

To sum up, you can use a portable generator to charge your electric vehicle, but expect it to happen at a snail’s pace and be more inconvenient than anticipated.

How Many Watts Do You Need to Charge a Tesla?

Since electric cars such as Tesla are built to need a large amount of power, it stands to reason that you will need a high number of watts to get them properly charged.

If you wonder why this is so, consider that the Tesla Model S can go from 0-60 mph in only 2.5 seconds, while also going at least 270 miles on a single charge.

If you are not careful, you may choose to get the first generator you find and assume it will work to charge your Tesla. 

However, that may or may not be true. 

Should you use a portable generator that possesses only about 1500 watts or perhaps less, we can assure you your Tesla will take at least a full 24 hours to charge, if it does at all. 

To have any chance you will have a charged-up Tesla in no more than 24 hours, you’ll need a generator with an output of 4000 watts or more. 

However, since the more watts they possess the bigger their size, you may not find a portable generator that will adequately fit inside your Tesla’s trunk. 

But if you do, make sure you are in a position where you can afford to wait around, and also have plenty of gas for your generator.

When is a Portable Generator a Practical Option for Charging a Tesla?

Though we have touched on many ways where it may not be practical to use a generator when charging a Tesla, there are times when using a generator is better than the other options in front of you, especially if your Tesla is almost completely out of power. 

If you are on the road quite a bit for your job or when you go camping or on other trips, having a generator available gives you the ability to know your Tesla can get recharged, even if you are in a remote area. 

Also, should you find yourself facing a prolonged power outage due to a natural disaster, rolling blackout, or other situation that will have you in the dark for a long period of time, you will still be able to give your Tesla the power needed to drive to stores and other places to get the necessities you and your family will need. 

As the popularity of electric vehicles like Tesla grows more with each passing year, we believe so too will the demand for generators that will make it easier to charge up vehicles in a faster manner. 

By having a generator at your fingertips, you’ll have one additional option to use if needed when charging your Tesla.

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Zach Reed

Hi, I'm the founder of! Having owned a wide variety of vehicles in my life, I was astounded at how hard it can be to find answers to common automotive questions. Rather than sit idly, I decided to create this website to help others!