How Long Can A Generator Run Continuously?

Although generators are usually used temporarily for emergency purposes, you never know how long you may have to go without power. There’s a good chance that sooner or later you’ll face a prolonged power outage where you won’t have access to the electrical grid for days. For instance, in the middle of a natural disaster.

How long can a generator run continuously without running into problems? What are the different types available? How do you get the most out of the generator you currently own? Here we’ll be addressing all those questions.

Consider the Type of Generator

The type of generator you purchase will determine how much energy it can provide before running out, as well as how well it produces that energy. This includes size, fuel source, and even the brand and model.

Standby generators are installed on your property and keep your home’s systems and supply appliances with continuous portable ac power during an outage. Larger models can produce over 150 kilowatts of clean power to handle all your appliances. However, consumer grade standby generators are mostly in the 8 to 20 kilowatt range.

Portable generators offer a great on-the-go option with a smaller size, but they’re mostly only good for low demand, short-term uses. While the largest portable generator is around 17 kilowatts, it’s large and heavy and so not all that portable.

You also need to consider fuel type. For example, solar-powered generators are a great option if you have ample sunlight and don’t plan on hooking up a lot of appliances. While they generally produce fewer watts and take longer to charge, you don’t have to plug them in or refuel them to get more energy.

How Long Can a Generator Run?

Homeowners can expect a standby generator to run for multiple months without running out of juice. However, you shouldn’t run a generator continuously for longer than 500 hours without a break or you risk damage to your generator and possibly your home’s electrical devices as well.

The run time of a portable generator will vary depending on the generator itself, the size of its fuel tank, and the how much power is being drawn.

If your portable generator runs out of fuel while under load, it could damage the internal coils. Once the coils lose their magnetism, your generator won’t function properly. Some models automatically shut down to avoid damage if the tank runs dry.

If your portable generator has such a feature, you shouldn’t have a problem running your generator continuously overnight. At most, you’ll wake up to a generator that has run out of fuel.

Standby generators are made to last much longer and can run continuously for around three weeks. Portable generators can run for about a week straight if they’re refueled.

How Long Will a Generator Run on Propane?

Unlike portable gasoline generators, portable propane generators can potentially run for multiple days without needing to be turned off. You can’t do this with gas powered generators because heat produced by the generator’s engine could ignite spilled gasoline.

If you have a piece of equipment called a changeover regulator valve, you can actually swap out an empty tank with a full one while the propane generator is still running. The main factor limiting runtime for this kind of setup will be a mechanical issue, such as running out of engine oil.

A 20 lb propane tank can fuel a typical portable generator for up to ten hours. A 100 lb tank can fuel a 12 kilowatt propane generator run for roughly 36 hours.

How Long Does a Generator Run on a Battery?

Unlike propane generators, you can’t as easily refuel battery-powered ones when you’re off the grid. The best power stations can keep a few appliances powered for a day or two before running out. You can always buy one that can be recharged using solar energy, though.

Lighter power stations usually come with smaller watt-hours. Heavier power stations come with larger battery sizes but take up more space. You’ll likely have to pay more if you want to run the battery for a longer period of time.

One of the benefits of using a power station is that you can use them indoors safely. They can also be recharged within a day. However, they won’t run for as long as a propane or gas generators or power major appliances.

What Affects a Generator’s Runtime?

Buying a used generator can help you save money, but it may not be as good as a new one. Generator technology is constantly evolving with additional features to improve your fuel economy and safety.

Some of these features include the ability to detect carbon monoxide and prevent power surges. In addition, an older system may have a longer start-up time and use more fuel than a newer one.

An inverter generator increases efficiency by varying engine speed to meet demand. It throttles the engine up and down as needed so it doesn’t have to run at maximum power the whole time.

Gas generators have a special limiting factor that propane and natural gas generators do not, and that is it’s built-in tank size. An open frame portable gasoline generator will usually have a larger gas tank than an enclosed generator. There are several Duromax generator dual-fuel models available that give you the flexibility to use whichever fuel gives you the best advantage in any given situation.

Probably the single biggest factor affecting runtime is the power load demanded. If you need to run a generator for a long period of time, keep in mind what’s plugged into it. Some appliances can drain energy even if you’re not using them. Only keep things plugged in that need the constant energy, such as a refrigerator or light sources.

How to Keep It Running Longer

There are some tips to keep your generator running well and for a longer time.

Change the oil routinely. This may be every 50 to 200 hours of operation depending on the brand and how often you use it (check out our how often should I change my generator oil article for more info.

Start it up every month to make sure it’s still working. That will also circulate the oil to lubricate the machine.

Avoid using old gas. You should always empty out your fuel from a generator’s tank after each use, even if it wasn’t used for long. Doing so helps to prevent varnish build-up that causes poor performance and possibly engine damage. See our generator maintenance pages for more information.

Unless you have a standby generator installed with high gauge electrical wiring, keep all appliances plugged in within 100 feet. The voltage can drop on longer runs, which decreases fuel efficiency and can cause appliance motor or compressor burnout. Click on the following link for more Generator Safety Tips.

Can I Power My House With a Generator Full Time?

Portable generators have a life expectancy of 1000-2000 hours of operation, while standby generators can last about 1500-3000 hours before needing to be rebuilt. This means you could only run a generator for about 1.5 to 4 months before needing expensive repairs.

Even then, you would not be able to run a generator continuously all that time as you would need to at least change the oil.

So trying to power a house full time with a generator would be impractical.

Find the Best Generator for Your Needs

A generator must be able to provide the energy you require in a time of need. But how long can you run a generator continuously before running into problems?

As it turns out, most portable generators will run out of fuel or battery capacity long before they overheat or start developing issues. They should also have safety mechanisms set in place so they turn off before completely running dry.

If circumstances and your power requirements allow it, the ultimate portable solution for continuous power supply would be one that never runs out of fuel: a solar generator.