Can a Portable Generator Run 24 Hours a Day?
Yes, a portable generator can run 24 hours a day. Westinghouse says its units can go 24/7 if operated and maintained to the manual. Here's how to keep a portable generator going around the clock.
Running a Generator Around the Clock
What the Manufacturer Says
Westinghouse puts it plainly in its FAQ. Its generators can run 24/7 if they're operated and maintained in line with the supplied instructions, and you should always stop the generator to refuel it.
So the engine isn't the limit. Fuel, oil and how hard you work it are.
Standby Units vs Prime Power
Not every generator is meant for weeks on end. Our Hyundai DHY8700SE-LRS listing points out that Hyundai's spec sheet says it isn't intended for prime power. It's built to run when the mains fail, not as your only everyday supply.
If you need a generator as your main power source every day, ring us first and we'll match a unit to the job.
Inverter Generator Continuous Run Time
You can run an inverter generator continuously for as long as one tank lasts. Then it has to stop, cool and take fuel before the next stretch.
Run Time per Tank
These are the makers' published figures, checked on 14 September 2026.
| Inverter generator | Tank | Maker's run time | Refuel stops per 24 hours |
|---|---|---|---|
| Westinghouse iGen4500AS | 13.5L | 17.8 hours at 25% | 1.3 |
| Champion 2.5kVA | 4L | 11.5 hours at 25% | 2.1 |
| Westinghouse iGen2250 | 4.7L | 11.3 hours at 25%, 3.8 hours at full load | 2.1 at 25%, 6.3 at full load |
| Westinghouse iGen3750S | 6.3L | 8.8 hours at 25% | 2.7 |
| Hyundai HY3500i | 6L | 5.5 hours at 50% | 4.4 |
On a light load the bigger tank wins, and the iGen4500AS covers most of a day on one fill. Work an iGen2250 flat out and you're stopping more than six times a day.
ECO Throttle on Long Runs
Westinghouse says to switch on the ECO throttle when an inverter will run for a long stretch at low or mid-range output. It minimises fuel use, noise and engine wear and tear.
Its iGen instruction manual adds two rules. Only use ECO once the engine has warmed up for at least five minutes, and switch it off when starting an air conditioner or pump.
Keeping It Running for 24 Hours
Refuelling Stops
Every tank ends with the engine off. The same manual says never refuel while the engine is running, and always let the generator cool before refuelling. Keep fuel containers somewhere well ventilated, away from anything that could ignite them, and wipe up any spill before you restart.
Oil Checks and Oil Changes
Oil is the other limit on a long run. Westinghouse's maintenance schedule has the oil checked before every use, changed after the first 20 hours, then changed every 100 hours or six months.
Run a new generator 24 hours a day and it hits that first oil change before the end of day one. After that it's roughly every four days. These engines hold very little oil, 350mL in the iGen2250 and 600mL in the iGen4500AS, so check it at each fuel stop while the engine's off.
The manual also notes a low oil shutdown. If the level drops too far the engine stops, which saves the engine but cuts your power at 3am.
Load Limits and Heat
Queensland's Electrical Safety Office says your generator should not run continuously at more than 80 per cent of its rated capacity. Hyundai's HY3200SEi manual says the same in its own words: for continuous operation, don't exceed the rated output.
On a 3,000W inverter that means about 2,400W for a long run, with the rest kept for motors starting up.
Light Loads on Diesel Generators
Diesels have the opposite problem. Caterpillar's paper on generator set underloading says running below 30 percent of rated output for extended periods causes wet stacking. If a diesel will tick over for days, give it some real work now and then.
Safety and Cost on Long Runs
A generator running day and night still needs someone looking after it. Energex says to never leave your generator unattended while it's running, and to turn it off at night and when you're away from home. If you're weighing up an overnight run, read is it okay to leave a generator running all night.
Energex also says to run it outside only, away from open windows, including your neighbours'. Our guide on whether generators can be used indoors explains why.
The fuel adds up over a full day, too. Our generator fuel consumption guide has what 24 hours costs on each machine.
So can a portable generator run 24 hours a day? Yes, with fuel stops, oil checks and a sensible load.
Want one sized for long runs? Try the generator finder, call 03 7056 6732 or SMS 0476 330 590.
