The EcoFlow Smart Generator 4000 Makes the Case for Owning Both a Power Station and a Generator

4 min readGenerators used to be the “go-to” solution when the power goes out, but with the proliferation of portable power stations, many folks now face the choice: Power station or generator? There are plenty of power stations, like the EcoFlow Delta Pro, with the capacity to be used for home backup. And unlike a generator, they can be used inside your home.The challenge with power stations is that their batteries need to be recharged. That becomes especially challenging when you’re talking about powering something like an RV, which can’t be connected to power if it isn’t available—when you’re off the grid, for example.The solution to uninterrupted power for your RV, or when the grid goes down for an extended period, doesn’t have to be a choice between power stations and generators—it may be both. EcoFlow has developed the dual-fuel Smart Generator 4000 that pairs with select models of its power stations to ensure you have continuous power whenever you need it.ProsAutonomous operation with appDual fuelInverter technology produces clean, stable powerConsNot ideal as a stand-alone generator, with only 2 outletsKey SpecsWatts (Running/Starting)Gas: 3200/4000, Propane: 2900/4000FuelGas/PropaneFuel CapacityGas: 1.58 gal, Propane: 20+ lbOutlets1 x 120V 20 Amps, 1 x 120V 30 Ampsweight83 lbThe Case for Pairing a Power Station and GeneratorWhile most power stations can be charged via solar panels, their maximum power output often exceeds the maximum solar input. This means they’ll be running a power deficit—using power faster than the batteries can recover. While solar panels might extend a power station’s runtime, in higher consumption situations it can still eventually run down without another charging option. That’s where the EcoFlow Smart Generator 4000 comes in.Winston ZhouWe tested the EcoFlow Smart Generator 4000, pair with their Delta Pro power station.The Smart Generator 4000 is compatible with the following EcoFlow power stations: Delta Pro, Delta Pro 3, Delta 3, Delta 3 Plus, and Delta 2 Max. Connecting the Smart Generator to one of these power stations with the included DC charging and communication cable unlocks autonomous operation and continuous power output.EcoFlow’s App Is Easy to Use and Provides Helpful InfoLike any other smart device, the EcoFlow Smart Generator 4000 connects to your phone via Bluetooth and WiFi using a mobile app. Here, you can monitor fuel consumption and output, as well as change settings. If connected via WiFi, you can do this from anywhere.Winston ZhouPairing the Smart Generator 4000 with EcoFlow’s app allows you to monitor and control generator functions.Using the EcoFlow app, you can set state-of-charge limits that automatically start the generator to charge the power station and shut it off again when complete. For example, you can set the low limit on the power station at 20 percent—when the state of charge drops down to 20 percent, it automatically starts the generator to charge—until it reaches the state of charge you set. In testing, we used several setting combinations and had no issues with controlling the stop and start functions.The app provides a lot of useful information, as well. It monitors generator fuel usage—for both gas and propane—and provides estimated runtime. You can also set the charging speed, monitor power output, and schedule times to start and stop the generator.Why Having a Dual-Fuel Generator Is Beneficial If the grid goes down due to a natural disaster, it may be difficult to get fuel when you need it. Having the ability to run a generator on gas or propane gives you the option to burn the fuel you have or the type that’s easiest to get. You can get up to about eight hours of runtime on a tank of gas, but if you have a 20-pound propane tank—the size most grills use—you can extend that by almost three times, depending on usage.Winston ZhouWhile you can use gas or propane, I almost exclusively use the latter on dual fuel equipment because it eliminates stale fuel starting issue over the long term.It’s important to note that propane doesn’t have the energy density that gasoline does. Because of this, the continuous power output is slightly reduced when using propane, down to 2,900 watts (from 3,200 watts for gasoline). Peak power is rated at 4,000 watts for both, using what EcoFlow calls “X-Boost technology,” which allows output to exceed normal limits for very short bursts to start devices that require more power to start.The advantage of using propane is that it can be stored for very long periods without breaking down—unlike gasoline, which can evaporate and leave glue-like deposits in the fuel system.Bonus: It Doubles as a Stand-Alone GeneratorWhile the Smart Generator 4000’s ability to connect to an EcoFlow power station is one of its most appealing qualities, it can also be used as a stand-alone generator by plugging devices into either of the 120-volt outlets provided on the front. One is a standard 20-amp outlet, and the other is a 30-amp RV-type outlet. The Smart Generator 4000 is an inverter generator, so it delivers very stable power and is safe to power your sensitive electronics.The VerdictFor folks already using EcoFlow power stations, the Smart Generator 4000 can be a fantastic addition to your auxiliary power plan. For folks without an EcoFlow power station, the Smart Generator 4000 could answer concerns about what happens when batteries run down.With EcoFlow’s app, I found that the power station and Smart Generator 4000 can be set up to provide uninterrupted power completely autonomously. It doesn’t matter if you’re concerned about emergency backup or keeping your RV systems running off the grid; the Smart Generator 4000 will help relieve runtime anxiety about how long the power station will last. And it beats moving solar panels and cables, trying to chase the sun across the sky.Shop the EcoFlow Smart Generator 4000More Generators We RecommendAnker SOLIX Smart Generator 5500Now 23% OffPulsar 7,250-Watt Dual Fuel Inverter GeneratorNow 8% OffDuroMax XP11000iHT Tri Fuel Inverter GeneratorBrad Ford has spent most of his life using tools to fix, build, or make things. Growing up he worked on a farm, where he learned to weld, repair, and paint equipment. From the farm he went to work at a classic car dealer, repairing and servicing Rolls Royces, Bentleys, and Jaguars. Today, when he's not testing tools or writing for Popular Mechanics, he's busy keeping up with the projects at his old farmhouse in eastern Pennsylvania.John Gilpatrick is a Senior Reviews Editor for Popular Mechanics, covering tools, home appliances, yard and garden accessories, and smart home tech. He previously worked for Men’s Health and has bylines on numerous other websites, covering topics as disparate as nutrition, tech, and pet care. He is also a former film critic who’s unusually fond of the Star Wars prequels, and he appeared on Pop Culture Jeopardy in 2025 while wearing jorts and a fanny pack. He is a member of the Online Film Critics Society (OFCS).