Generac portable generators for home backup
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Quick answer
Generac's portable line runs from small recoil-start units to tri fuel models. The GP3600 makes 3,600 running watts and weighs 105 pounds. The GP6500 electric start makes 6,500 running watts and 8,125 starting watts, at 182 pounds. The GP9500E Tri Fuel makes 9,500 running watts on gasoline and also runs on propane or natural gas, at 219 pounds. All three list COsense, which shuts the engine off when carbon monoxide builds up. Even so, run any generator outdoors only, far from the house.
Three Generac portables by the numbers
| GP3600 (G0077211) | GP6500 E-start (G0077131) | GP9500E Tri Fuel (G0080632) | |
|---|---|---|---|
| Running / starting watts | 3,600 / 4,500 | 6,500 / 8,125 | 9,500 / 12,500 (gasoline) |
| Fuel | Gasoline | Gasoline | Gasoline, propane or natural gas |
| Tank | 3.7 gal | 7.9 gal | 7.5 gal |
| Run time at 50% load | 9.3 h | 11.5 h (spec table) | 9.5 h gasoline, 4.5 h on a 20 lb LP tank |
| Engine | 212 cc OHV | 389 cc OHV | 500 cc OHV |
| Start | Recoil | Electric, 12 V battery | Electric, battery included |
| Weight | 105 lb | 182 lb | 219 lb |
| CO protection | COsense | COsense | COsense |
Generac's GP6500 page lists two run times. The feature list says up to 10.5 hours at 50% load, and the spec table says 11.5. Plan with the lower figure.
Which size fits your outage
- GP3600. Generac pitches it for home projects, tools and essential electricity in an outage. It is light enough to roll out of a garage, and its 3.7 gallon tank keeps refueling simple.
- GP6500. The middle choice when a fridge, freezer, sump pump and some lights must run together.
- GP9500E Tri Fuel. For larger loads, and for homes with a natural gas line or propane on hand. Generac says you switch fuels with the turn of a dial, and it includes a 4 foot LP hose.
Add up the running watts of everything you need at once, plus the biggest motor's starting surge, and pick the unit that covers it with room to spare.
PowerRush and starting watts
Generac says PowerRush delivers over 40% more starting capacity on the GP3600 and GP6500. It describes this as extra current on demand, above rated output, when electric motors start. That helps with well pumps, sump pumps and refrigerator compressors, which draw a burst at startup. It does not raise the running watts. Size your steady loads to the running figure.
COsense and where to run it
Generac says COsense will automatically shut the GP6500 off if it is used indoors or in an enclosed space and increased CO is detected. Treat that as a backup, not permission. CPSC says to run portable generators outdoors only, at least 20 feet from the house, never in a garage, basement, crawlspace or shed, with exhaust pointed away from doors, windows and vents. NFPA adds to let the generator cool before refueling.
Connecting to the house
Generac lists the GP9500E as compatible with its HomeLink manual transfer switches for safe home backup power. NFPA says that if you must connect a generator to house wiring, a qualified electrician should install a properly rated transfer switch to the National Electrical Code. Otherwise, plug appliances directly into the generator or into heavy-duty, outdoor-rated extension cords with all three prongs.
Upkeep Generac builds in
- Low-oil shutdown on all three protects the engine if oil runs low.
- Hour meter on the GP6500 tracks maintenance intervals.
- Oil capacity is 0.63 quart on the GP3600 and 1.06 quarts on the GP6500 and GP9500E.
- Never-flat wheels and a fold-down handle come with all three.
Generac also sells some models in separate 49ST and 50ST versions. Check that the listing you buy matches the version sold for your state.
What to look for when you buy
Generac GP3600 with COsense
Best for: Fridge, lights and phones, or tools, in a light package
Generac lists 3,600 running and 4,500 starting watts, 9.3 hours at 50% load on a 3.7 gallon tank, a 212 cc OHV engine, COsense and 105 pounds.
Watch out: Recoil start only, and the smallest tank of the three.
See options on Amazon (opens Amazon in a new tab)Generac GP6500 electric start with COsense
Best for: A fuller set of household essentials during an outage
Generac lists 6,500 running and 8,125 starting watts, a 7.9 gallon tank, a 389 cc OHV engine, electric start, an hour meter and COsense.
Watch out: 182 pounds. Generac's page gives both 10.5 and 11.5 hours run time at 50% load.
See options on Amazon (opens Amazon in a new tab)Generac GP9500E Tri Fuel
Best for: Bigger loads with a choice of gasoline, propane or natural gas
Generac lists 9,500 running and 12,500 starting watts on gasoline, a 500 cc engine, a 4 foot LP hose, COsense and HomeLink transfer switch compatibility.
Watch out: 219 pounds, and only 4.5 hours on a 20 pound LP tank at 50% load.
See options on Amazon (opens Amazon in a new tab)Questions people ask
- What is COsense on a Generac generator?
- Generac's carbon monoxide shutoff. It automatically shuts the generator off if increased CO is detected, such as when it is used in an enclosed space.
- How long does a Generac portable generator run?
- At 50% load, Generac lists 9.3 hours for the GP3600, up to 10.5 or 11.5 hours for the GP6500, and 9.5 hours on gasoline for the GP9500E.
- Can a Generac portable run on propane?
- The GP9500E Tri Fuel runs on gasoline, propane or natural gas. Generac lists 4.5 hours on a 20 pound LP tank at 50% load.
- How far from the house should a portable generator be?
- CPSC says at least 20 feet, outdoors only, with the exhaust pointed away from doors, windows and vents.
Sources
- GP3600 Portable Generator with COsense (G0077211), Generac
- GP6500 Portable Generator Electric Start with COsense (G0077131), Generac
- GP9500E Tri Fuel Portable Generator (G0080632), Generac
- CPSC Warns of Generator, Carbon Monoxide and Fire Hazards Ahead of Hurricane Season, U.S. Consumer Product Safety Commission
- Generator Safety tip sheet, National Fire Protection Association