How Long Can You Safely Run a Portable Generator? Answered


Are you wondering how long you can safely run your portable generator?

Believe it or not, that’s a very common question. In today’s electricity-geared world, running out of power is simply not an option, so it stands to reason that you’re interested in knowing exactly how long your power source will last.

Below, you’ll find some useful information that will hopefully answer your most burning questions and provide a clearer perspective on the situation.

Keep reading to keep the power on!

Safe Run Times By Model

There are lots of external factors that could change how long it is safe for you to run your portable generator. Some of them are:

  • How cool you can keep the generator
  • How much oil there is in the generator’s engine
  • How much fuel you have on hand
  • The temperature outside

To illustrate this a little better, check out this simple table:

Portable Generator Fuel TypeHow Long You Can Safely Power the Portable Generator
GasolineUp to 16 hours. You should not refill the generator while it’s running.
PropaneIf managed well, between 150 and 200 hours.
DieselWith a steady supply of diesel and careful observation, up to 500 hours

Portable generators are great to have in case of a blackout at home or to stay connected with the world while on a camping trip. These appliances are extremely convenient, and there are many models out there that won’t burn a hole in your pocket.

Portable generator on campsite
Portable generators provide more freedom: especially when camping

You may wonder how long you can run yours without running into problems, and the answer is: it depends. The runtime of your portable generator will vary greatly depending on the type of fuel that it runs on. There are other additional factors worth considering, and that we’ll explore below.

But first things first.

Gasoline vs Propane Portable Generators

There are two main types of portable generators on the market – propane models, and their gasoline counterparts. While they both do a great job at saving you from an emergency, the former will typically run for longer than the latter due to the substance it uses to draw power.

As you can imagine, in addition to what was said above, there are other major differences between gasoline and propane portable generators, such as:

Portable Gasoline GeneratorsPortable Propane Generators
Should not be refueled while the generator is running. Can be refueled while the generator is running
Should be cooled down before refueling the generator.Can be refueled continuously as long as the engine is kept cool.
Their runtime depends on the size of the fuel tank and the amount of energy you consume.Their runtime depends on the amount of oil in the generator’s engine
Can run for up to 16 hours.Can run for anywhere between 150 to 200 hours.

Cons of Gasoline Portable Generators

Now, you’re probably wondering why there’s such a massive difference between one portable generator and the other. Well… the main reason behind this is the ease of refilling. As opposed to propane models, gasoline generators can’t be topped up while they’re hot, as the fumes in the air could cause an explosion.

And to make matters worse, while larger gasoline portable generators can last up to 16 hours, there are many models out there with smaller tanks that last much less.

Pros and Cons of Propane Generators

These, unlike gas generators, can be refilled while they’re hot. This gives you the potential to run yours for anywhere between 150 and 200 hours.

That being said, not everything’s peachy, and there are a few things that could affect the runtime of your propane generator. Below, you’ll find some of the most common problems you can encounter, as well as some countermeasures you can try to keep them from shortening the generator’s run time:

ProblemHow to Stop it From Affecting Your Generator’s Runtime
A Build-Up of HeatA generator will begin to overheat once you have used it nonstop for more than 24 hours. You should also try to blow cool air from a fan on the engine to prevent it from overheating. 
The Amount of Oil in Your Generator’s Engine

Most generators will shut off when the oil levels are low in the engine. Make sure that you top up the oil levels before you begin using the generator. The generator should run for 150–200 hours before you have to refill the oil.
The Temperature Running the generator at a high wattage will make it heat up more. If the external temperature is hot, the generator could overheat. Consider running the generator at a lower wattage, and keep it away from direct sunlight.
Portable generator
Propane generators can be refilled while hot, which gives them a higher runtime

Can a Generator Run in the Rain?

When you go out camping, you prepare yourself for all kinds of weather. You may pack an extra snug sleeping bag for chilly nights. Or a waterproof tent for damp mornings. You may even consider an insulated sleeping pad or a windbreaker.

But what about your generator? Is it prepared for a turn in the weather?

Not always. In fact, it’s not typically safe for you to run your appliance in wet weather, such as:

  • Rain
  • Snow or sleet
  • Hail

 It’s worth emphasizing that a wet generator is a dangerous one. So, if you suspect there’s some inclement weather on the way, you should avoid using it. But let’s be honest, no one plans to be in a tent in the woods in the middle of a storm. So, what can you do if you get caught outside and need to run your generator in wet weather?

Read on to get some great tips!

Special Canopies

You can buy a canopy for your unit that looks like your generator’s own private tent. The canopy does the following:

  • It protects the generator from high-speed winds.
  • It protects all the areas of the generator that you don’t want to get wet. 
  • It maintains good airflow to the engine so that it doesn’t overheat.

Overall canopies are great, but as you can imagine, they’re not without their flaws. Here are some Pros and Cons to take into account:

-Portable and easy to set up and dismantle.
-Good at protecting the generator from bad weather.
-May not be very effective in heavy rainstorms. 

Steel Enclosures

You can buy a steel enclosure that locks over the entire generator. The steel enclosure does the following:

  • It stops water from leaking into the generator. 
  • It protects the generator from high-speed wind.
  • It maintains good airflow to the engine so that it doesn’t overheat.

Here are some pros and cons of using a steel enclosure to protect your generator:

-It protects the generator from bad weather. -You will have to hire a professional to install the steel enclosure. This could be pricey.
-Not portable. 

Retrofitted Plastic Enclosures

You can buy a retrofitted plastic enclosure that locks over the entire generator. This type of enclosure tends to be cheaper than steel enclosures. A retrofitted plastic enclosure does the following:

  • It stops water from leaking into the generator.
  • It protects the generator from high-speed winds.

Here are some pros and cons of using a retrofitted plastic enclosure to protect your generator:

-Good at protecting your generator from bad weather. 
-Cheaper than a steel enclosure.
-A retrofitted plastic enclosure could easily become subject to overheating and possibly fire. This could happen if you use your generator for extended periods or on very hot days. 


If your power is down, you likely want to keep your generator running as long as possible. But there are a few things you should know and do before you attempt to keep a generator running. I am sure this article has given you some tips on how you can safely extend your appliance’s runtime.

If this article has helped you and proved interesting to read, I encourage you to check out some of our other articles and free guides, and why not? Maybe even join our mailing list!

Have a great day.


Hi there! I’m Craig, and I’m the founder of Appliance Analysts. When it comes to appliances and anything electrical, I’ve always loved opening things up, figuring out how they work, and fixing them. This website is where I share free advice from myself and our experts to help our readers solve their appliance/HVAC problems and save money. Read more