Portable generators for sale.
We focused on moderately priced portable and stationary models that deliver 5,000 to 7,000 watts, enough for most needs. Portables cost the least and can be stored in a garage or shed when you don't need them. A lower-priced model powered refrigerators, well pumps, and other home gear almost as well as a more expensive top-scorer.
Stationary models install permanently outside your home and start automatically when needed. And because they run on propane or natural gas instead of gasoline, they offer extended or unlimited run time.
Buying a generator is just the beginning. Many models don't come with parts that you'd think would be part of the price. And some could let you down when you need them most or put an added load on appliances. Here are the details.
Generators are typically sold by wattage. How much they put out determines not only how many lights and appliances you can run at once but how well they run. For example, a refrigerator often requires about 600 watts, a portable heater 1,500 watts, a window air conditioner 1,000 watts, and lights 60 to 200 watts. Our wattage calculator provides an average wattage rating for most appliances and devices to help you to tally your needs.
"Batteries not included" applies. Several portables offer electric starting. But the battery required for that feature usually costs an extra $50. And if you think all portables have wheels, think again: They're a $150 option on one model we tested.
Some slipped when demand surged. All of the tested generators met their basic wattage claims. Manufacturers also make higher surge-wattage claims for the extra power needed when fridges, air conditioners, and pumps cycle on. Subpar surge wattage lowered the power-delivery scores of some models in our tests.
Some can overheat appliances. Our power-quality test judges the ability to deliver the 120 volts that home circuits usually need. Most met that challenge although one model was more than 10 volts shy under a heavy load and voltage from another was also low--and slightly uneven. Both conditions make motorized appliances and some electronics run hotter.
How to choose
Decide what you really need to power. If that includes a central air conditioner or an electric dryer or oven, you'll need a larger generator than the ones we tested. Here's what else to keep in mind:
Count on a transfer switch. It costs about $500 to $900 installed and connects a portable generator to your home's circuit box as with a stationary model. In addition to eliminating the risk and hassle of extension cords, the switch protects the generator and appliances from damage when grid power returns and keeps the generator from endangering technicians working on the power lines.
Think about the fuel. Most portables use roughly 8 to 22 gallons of gasoline a day, compared with four to eight 20-pound tanks of propane for portable models. (A 250-gallon tank for stationary units can run 8 to 15 days.) Buying and storing lots of fuel before a storm can be unwieldy, although you can pour unused gasoline into your car's gas tank.
Look for smart features. All but two of the portable generators in our tests turn themselves off when engine oil is low. And the fuel shutoff on all tested gasoline models lets you run the engine dry to draw gas out of the fuel system to keep it from fouling parts if it degrades during storage.
Play it safe
Powering too many appliances will trip the generator's circuit breakers, causing power loss. Be sure what you're powering is within the generator's rated wattage; most transfer switches make that easier by showing wattage levels.
And protect against carbon monoxide, which kills about 86 people each year--and sends thousands more to the emergency room. Run any generator outdoors and away from the house, far from doors, windows, and anywhere else air enters the house. Never run it in a basement or garage; even with the garage door open, it endangers people inside the house.