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Consumer Reports recently finished testing 14 new generators for performance and safety, and they’re among the best portable models we’ve ever rated. In fact, eleven of them score well enough to earn be recommended by CR.
That’s no coincidence, given that all but one incorporate safety features that dramatically reduce the risk of carbon monoxide poisoning. As a mission-driven organization that prioritizes consumer safety, CR considers these features so critical that a portable generator without them can’t be recommended, regardless of how well it fares in our performance tests.
The mandatory feature is an automatic carbon monoxide shutoff: A sensor detects CO and cuts the engine if concentrations build up to dangerous levels. The generator can’t be restarted until the CO sensor is reset. Another safety feature, offered on four of the newly tested models, is a low-emissions engine designed to produce less carbon monoxide in the first place. (Home standby generators also produce carbon monoxide, but they don’t have the safety features because they’re permanently installed outdoors and are typically subject to building codes designed to ensure safety.)
Most new portable generators come with CO safety features because over the past few years, manufacturers have adopted voluntary safety standards designed to help reduce incidences of carbon monoxide poisoning, which kills 60 to 70 people a year.
You can see CR’s evaluation of these safety features reflected in the CO safety technology score in our ratings.
For a generator to earn an Excellent score for safety, it must automatically shut down when it’s used in an enclosed space, and it also must keep CO emissions at a safer level if the generator is running in a partially enclosed space, such as in a garage with the door open (which you should never do). In an open garage, fresh air outside can dilute the concentration of CO inside, fooling the CO sensor yet allowing the gas to hover at levels that can be dangerous over longer periods.
Models that produce relatively high levels of CO with the door open earn a rating of either Good or Very Good for CO safety technology, depending on the levels we record. And any model without a CO safety shutoff will earn a rating of Poor—taking it out of the running for our list of recommended products.
“This latest batch of generators we tested shows that these tools can blend safety and performance,” says Misha Kollontai, CR’s test engineer in charge of generators. “The majority of the new models we tested make major improvements over older generators in terms of safety, and still managed to deliver power reliably.”
No matter which generator you have, use it outdoors only and place it at least 20 feet from your home, with the exhaust directed away from any open windows or doors. CR recommends having a licensed electrician install a transfer switch, which connects a generator to your home’s circuit breaker panel, allowing you to power entire circuits at once. Otherwise, you should use outdoor-rated extension cords to plug individual appliances directly into the generator. Make sure the cords are at least the gauge specified by the generator manufacturer and long enough that the generator can remain 20 feet from your home.
How CR Tests Generators for Performance
While safety is essential, our performance testing ensures that a generator will work as promised in the moment you need it most. To do that, our expert engineers load up every generator we assess with a variety of essentials you might want to power during an outage, like a space heater, refrigerator, or window air conditioner. We make sure the generator can handle the load it promises and also determine what happens when a sudden spike in voltage hits, like what would happen if the compressor in your refrigerator kicked on when the generator was already close to capacity. The best models take that in stride, while others bog down or even stall. We also look at how easy it is to move and use a generator, as well as how efficiently it uses gasoline and how long it runs on a single tank.
Generator Rankings, by the Numbers
13: recently tested models with safety shutoff
11: recently tested models that are recommended by CR
34: total gasoline-powered generators in CR’s ratings
Best Portable Generators From CR's Tests
What, exactly, is a “portable” generator, anyway? That designation can include everything from a little 30-pound generator you’d use at a campground to charge your phone, all the way up to a 250-pound behemoth, capable of powering your entire house through a sustained outage. Think of a portable generator as any model that’s not a home standby generator.
Here, we’ve divided portable generators into three common styles you’ll find, with some notes on what each can do.
Our newly updated ratings include results for dozens of portable generators, as well as home standby generators. If you’re just starting to shop for a generator, start with our generator buying guide to get a sense of the differences among types. CR Members can also jump to our ratings or read on for ratings and reviews of the best portable generators from our tests.
Consumer Reports is an independent, nonprofit organization that works side by side with consumers to create a fairer, safer, and healthier world. CR does not endorse products or services, and does not accept advertising. Copyright © 2020, Consumer Reports, Inc.