With winter storms already brewing, harsh weather is about to bring more power outages across the country. Having backup power available can help you weather the storm more safely and comfortably, which is where the popular EcoFlow DELTA Pro 3 comes in. You get 4,096Wh of stored power, 4,000W of continuous output, the capacity for 8,000W surge, and a seamless 10ms UPS switchover for sensitive gear all in one box that run either 120V or 240V as needed. This means you can keep the food in the fridge cold, keep the water pump flowing, charge phones, and power your WiFi router to stay online. Winter outages are rising across the U.S., with 80 percent of major outages tied to weather and nearly a quarter from winter storms (which makes a ready backup more than a luxury right now). NOAA’s data shows the five year average of billion dollar disasters more than doubled compared with the long term average, which makes being prepared that much more important.

About EcoFlow

EcoFlow launched in 2017 with roots in DJI drone battery engineering and quickly grew into a leading portable power brand. The original DELTA Pro even made TIME’s Best Inventions list in 2021. DELTA Pro 3 builds on that track record with higher output and streamlined home integration. In a season where winter peak demand is rising and grid planners flag elevated risk in several regions, a portable power supply that can stand in for a small sub panel is especially valuable.

What you get in the box

Out of the box you get the unit, AC cable, and basics to start charging and powering devices through standard outlets and the RV plug. The app pairs quickly with the battery pack and highlights charging limits, UPS settings, and circuit priorities. The hardware is fairly large (as is necessary for this much backup power), but the handle and large wheels help make it more portable than some other systems. Setup is straightforward for beginners, since it can really just be a plug and play solution. If you want to connect to a transfer inlet or Smart Home Panel 2, plan an electrician visit and follow the manufacturer’s guidance on 120 V or 240 V selection (since it cannot output both at once).

Core hardware specs

Capacity for the DELTA Pro 3 is a generous 4,096Wh with LFP cells rated for 4,000 cycles while still maintaining 80 percent charge. The inverter supplies 4,000W continuous and can handle a 8,000W surge. You can select 120V or 240V from the front panel, which makes it possible to run high powered appliances such as clothes dryers. UPS transfer is listed at 10ms, meaning switching from line power to battery power is practically seamless which helps with desktops and networking. The battery pack carries an IP65 rating while the main unit is IP20, so you should run it indoors or under shelter. The warranty is a generous five years. There are four NEMA 5-20 outlets, one TT-30 for RVs, one 6-20R for 240V, plus USB A and 100W USB C ports (and Anderson for DC).

Charging options explained

On-grid charging supports standard Level 1 through the AC inlet and Level 2 up to 4000W when you add EcoFlow’s EV X Stream Adapter to the AC in out port. Solar input tops out at 2,600W across two PV inputs, one high voltage up to 1,600W and one low voltage up to 1,000W. Vehicle charging is available from 12V or 48V sources and EcoFlow’s 800W Alternator Charger is a solid RV add-on if you want meaningful charging while driving.

Solar input options

Two PV ports let you mix a higher voltage string with a lower voltage string. Be sure to keep each string inside the listed voltage and current windows and use proper MC4 connectors and breakers. A practical setup for winter sun is a four panel series string around 400 to 600W total on the low voltage input and a larger series string on the high voltage side to approach the 1,600W ceiling when skies clear. Follow EcoFlow’s FAQ specifics for voltages and the 2600W combined cap, and consult a licensed installer for permanent wiring or if you plan to install any on your roof.

Runtime game plan for winter loads

Real world usable energy is usually a bit lower than the numbers suggest on all battery storage solutions once you include inverter and conversion losses. With 4,096Wh, budget about 3,400 to 3,600Wh to be conservative. That yields roughly 20 to 24 hours for a 150W fridge, about 10 to 12 hours for a small 300W space heater on low, five to six hours for a 600W sump pump if it runs half the time, or nine hours for a 400W router, lights, and TV combo at 200W average. CleanTechnica’s long term test saw about nine hours on an older RV air conditioner with one extra battery that doubled capacity (which matches the math).

App, smart features, and home integration

The EcoFlow app gives you control over charge limits, UPS behavior, and time of use schedules so you can top up off-peak and discharge during peak pricing to safe money on your electric bill. Pairing with Smart Home Panel 2 lets you feed up to 12 circuits with about 20 ms switching. You can parallel three inverters to reach 12kW and expand storage dramatically for longer events. That turns the DP3 from a big battery on wheels into a flexible home power node. Tom’s Guide also highlighted time of use savings from daily cycling during a heat wave, which demonstrates that the app features are not just for emergencies but rather they can be used every day.

Noise, ports, and usability

Under typical loads, the fans are restrained (which suits bedroom or living room placement). The outlet mix covers common needs including the RV TT-30 and the 240V 6-20 for appliances. The sliding side doors and the simplified physical interface are well designed, which matters when you are troubleshooting in a dark hall with a flashlight in your teeth. It is worth noting the lack of a cigarette lighter-style 12V port which some campers still prefer. If that is important to you, you can use the Anderson port with a proper adapter.

Head to head: EcoFlow vs other brands

The Anker SOLIX F3800 starts at 3,840Wh with a very strong 6,000W inverter, dual voltage, and up to 2,400W solar input. It can scale big for whole home backup but it weighs more than the EcoFlow and costs more at similar capacity. The Jackery 5000 Plus begins at 5,040Wh with dual voltage and claims up to 7,200W output, and it can scale to 60kWh for long outages. BLUETTI AC500 is modular with a 5,000W inverter but needs two inverters for 240V split phase. EcoFlow splits the difference with smoother app control and an easier single box 240V option. Pick Anker for maximum inverter strength, Jackery for larger base capacity, BLUETTI for modular value, and EcoFlow for the most polished ecosystem,UPS balance, and best all-around performance.

Brand reputation

TechRadar’s review called DELTA Pro 3 a game changer for high capacity portable power with smart home integration. Tom’s Guide reported smooth sailing through real outages and even daily 'peak shaving' to reduce demand in peak periods to save on bills. CleanTechnica’s long-run test found the unit handled camping duty and AC loads well with expansion. EcoFlow is one of the few brands thoroughly tested and trusted for home backup use, and it is known for coming out on top despite being the less expensive option.

Benefits

The DELTA 3 Pro offers a generous 4kWh capacity in a single chassis that still rolls around the house. It provides clean 120V or 240V from one unit with a simple front panel selection. It can handle fast Level 2 charging with the optional adapter. It includes a solid app and a Smart Home Panel 2 path for circuit level control. It offers a useful outlet mix with RV and 240V receptacles. Its ecosystem includes add-ons like the 800W Alternator Charger to make RV life easier.

Considerations

Not surprisingly, the unit is heavy and large which limits true portability between floors, but it is easier to move around than most in this size range. No simultaneous 120 V and 240 V output is available which means you pick one at a time. Two different PV input windows add wiring complexity for first timers, but basic planning makes this a minor issue. No native cigarette lighter style 12V port is present, which might be a shortcoming to some. Most of these have easy workarounds, like an Anderson to 12 V socket adapter and a quick talk with an installer for the PV stringing plan.

Winter Tips

Get DELTA Pro 3 if you want a single box that covers fridges, sump pumps, networking, lights, a window AC, or a single 240V tool or appliance on demand. It shines for suburban outages where rolling the unit to an inlet and flipping a few circuits keeps life normal. Before the first cold snap, label your critical loads, test the UPS, set a charge limit to protect battery health, and try a one-night simulation so you know what runs and for how long. Keep it indoors or under shelter since the main unit is not waterproof.

Vetted Verdict

The DELTA Pro 3 hits the sweet spot for beginners and seasoned tinkerers who want real home backup without a permanent install. It is easy to live with, grows into a circuit-based system if desired, and plays well with solar options and vehicles. Competitors may be able to top it in specific lanes like pure inverter grunt or base capacity, but EcoFlow’s ecosystem and user experience are hard to match and overall it is a winning package. With winter storms trending up, this feels like a great time to pick one of these up. You hope you will not need it, but you will be glad you have one when you do.