DELTA Pro Ultra FAQ: Everything You Need To Know


When it comes to energy independence and security, EcoFlow DELTA Pro Ultra is the hybrid solar generator and home backup battery solution that changes the game.   

For the first time, EcoFlow introduces a product that gives you all the convenience of a traditional grid-tied solar panel system and uninterrupted backup power during even extended outages.

If you’re looking for an expandable residential solar power solution that can provide enough electricity to power your entire home full of high-wattage appliances and HVAC systems — look no further than EcoFlow DELTA Pro Ultra.

Just check out these 5-star customer reviews!

If you’ve heard the buzz about EcoFlow DELTA Pro Ultra but still have some questions, you’ve come to the right place.

Below are the most frequently asked questions from our website and community — which you can join now for immediate discounts!

Don’t see your question on the list?

Feel free to ask away in the comments.

Is EcoFlow DELTA Pro Ultra an On-Grid or Grid-Tied Solar Power System? 

No. EcoFlow DELTA Pro Ultra is a hybrid solar + storage solution that offers many of the convenience of on-grid photovoltaic systems with the energy security of a home backup battery built in. Traditional grid-tied PV systems DO NOT work during blackouts.

However,  EcoFlow DELTA Pro Ultra does not offer bidirectional connectivity to the utility grid. It’s not capable of net metering or selling electricity to your utility provider. By integrating EcoFlow DELTA Pro Ultra with your home circuitry using the Smart Home Panel 2 or a transfer switch, you can count on an uninterrupted electricity supply — even during extended power outages. Use EcoFlow DELTA Pro Ultra during on-peak billing hours and switch to utility power during off-peak to save on your electricity bills. Or connect up to 42 x EcoFlow 400W rigid solar panels and take your home completely off-grid.

Is EcoFlow DELTA Pro Ultra Eligible for the 30% Federal Solar Tax Credit? 

Yes. If you’re a US taxpayer and resident, you should be eligible for the Renewable Clean Energy Credit of up to 30% of the total purchase and installation cost of EcoFlow DELTA Pro Ultra and solar panels. There’s no cap on the credit amount, and you can apply for multiple years if you end up expanding your system in the future. Receiving the Residential Clean Energy Credit does not affect your eligibility for any other local or state solar tax incentives that may be available depending on your primary residence’s location.   

Is EcoFlow DELTA Pro Ultra a Standby Generator?

Yes, EcoFlow DELTA Pro Ultra is a standby generator — but better! Because traditional gas, diesel, or propane standby generators emit carbon monoxide and other poisonous fumes, they must only be operated outside. Typically, the tank that stores the fossil fuel will require a concrete platform to be built on your property for installation. It must be a safe distance from your home. Depending on where you live, the installation requirement will likely be specified by laws and building codes and require official inspections. On the other hand, EcoFlow DELTA Pro Ultra produces no toxic emissions and can be operated inside or outside your home. With AC output options of 7.2kW, 14.4kW, and 21.6kW, it can provide enough electricity to power almost any home. Battery storage capacity starts at 6kWh and is expandable to 90kWh — enough to run most homes off grid for a month without recharging. When it comes to recharging, you have six options.

  • Up to 42 x EcoFlow 400W rigid solar panels
  • Grid-tied AC
  • Smart Home Panel 2
  • EV Charging Stations
  • Smart Generator (Dual Fuel)
  • DC (Car Adapter)

Unlike traditional standby generators, there are no ongoing fuel costs if you charge EcoFlow DELTA Pro Ultra with clean, renewable solar power — and no routine maintenance is required.  

How Many Appliances Can You Run With EcoFlow DELTA Pro Ultra?

With AC output starting at 7.2 kilowatts and expandable to 21.6kW with 3 x EcoFlow DELTA Pro Ultra Inverters, there’s pretty much nothing you can’t run. You can even charge an EV with EcoFlow DELTA Pro Ultra! Despite offering massive AC output, you’ll need to do some math to determine how many appliances you can operate simultaneously — and for how long. A single inverter and 1 or 2 x EcoFlow DELTA Pro Ultra Home Backup Batteries will be sufficient to power most apartments and small homes. However, if you want to operate high-wattage systems like central heating and air conditioning in addition to major appliances, consider 2 x inverters for 14.4kW AC output or 3 for 21.6kW. You’ll also want to add more batteries for extended outages. Thanks to EcoFlow DELTA Pro Ultra’s modular design, you can add LFP batteries in 6kWh increments up to 90kWh — enough electricity to run most homes off-grid for up to a month.

How Long Will EcoFlow DELTA Pro Ultra Power My Whole Home?

No two households are exactly alike in their electricity consumption patterns. To ensure that you have sufficient battery storage and electricity generation potential, you’ll need to calculate the combined wattage of all the appliances you want to run simultaneously. Then, you must estimate how long you’ll want to operate them between recharges. If you’re generating your own electricity with solar panels, your EcoFlow DELTA Pro Ultra will constantly recharge while operating during the day — especially during peak sunlight hours. With the option to expand EcoFlow DELTA Pro Ultra to 90kWh of battery storage, 21.6kW of AC output, and add up to 42 x EcoFlow 400W rigid solar panels, you can run your entire home off-grid indefinitely. Just make sure to do the math to ensure you have enough electricity to meet your family’s unique needs.

Is EcoFlow DELTA Pro Ultra a Home Backup Battery or Solar Generator?

It’s both! EcoFlow DELTA Pro Ultra offers modular LFP home battery backup from 6kWh to 90kWh of storage capacity. Because EcoFlow DELTA Pro Ultra is a hybrid solar generator, you can recharge directly from the utility grid and add up to 42 x EcoFlow 400W rigid solar panels for 16.8kW of photovoltaic charge potential. It doesn’t stop there. You can also charge EcoFlow DELTA Pro Ultra at EV charging stations or using a fossil fuel generator like EcoFlow Smart Generator (Dual Fuel). Unlike traditional grid-tied solar panel systems, EcoFlow DELTA Pro Ultra can send and receive electricity from the utility grid AND provide uninterrupted power during a blackout.          

Can EcoFlow DELTA Pro Ultra Charge My Electric Car (EV)?

Yes, EcoFlow DELTA Pro Ultra provides Level 1 and Level 2 charging for electric cars and vehicles. With the EcoFlow EV X-Stream Adapter, you can also recharge DELTA Pro Ultra with an EV pile at home or on the road at thousands of L2 EV charging stations across North America. With the optional suitcase-style trolley, EcoFlow DELTA Pro Ultra is much more portable than you might think for such a powerful inverter and backup battery.   

How Many Years Will EcoFlow DELTA Pro Ultra Last?

Unlike outdated solar battery technologies like lead-acid and nickel-cadmium (Ni-Cad), lithium iron phosphate (LFP) battery chemistry doesn’t degrade significantly over time. But all rechargeable batteries lose storage capacity with use. However,  LFP, also known as LiFeP04, batteries can be charged and discharged many more times than lead acid or traditional lithium-ion (Li-ion) batteries. The lifespan of rechargeable batteries is measured in cycles, with each cycle being one full charge and discharge of the unit. The “cycle life” specification is the best indicator of how long a rechargeable battery will last before its storage capacity begins to diminish. You have experienced a similar phenomenon with your smartphone. Long before it actually stops working, you’ll have to recharge it more often. The same thing happens with solar and home backup batteries. EcoFlow DELTA Pro Ultra provides 3000 cycles before its storage capacity is reduced to about 80%. That’s 6x longer than power stations with comparable capacity and output and enough for over 10 years of daily use. Lead acid and Ni-Cad batteries typically last between 500-1000 cycles. Traditional Li-ion batteries last about 1000-1500. 

Is EcoFlow DELTA Pro Ultra Expandable? 

Is it ever! EcoFlow DELTA Pro Ultra was designed with expandability in mind. You can customize your setup to meet your family’s unique home backup and solar generator needs. One of the features that sets EcoFlow DELTA Pro Ultra apart is its modular design. EcoFlow DELTA Pro Ultra Home Backup Battery (LFP) provides 6kWh of electricity storage, and you can add up to 15 batteries for total system capacity of 90kWh. Purchase all the storage you require at once or add to your system over time as your household electricity needs grow. It’s not just the storage that’s expandable, though. Connect up to 3 x EcoFlow DELTA Pro Ultra Inverters together for 7.2kW, 14.4kW, or 21.6kW of AC output — more than enough to power almost any home. When it comes to solar panels, you’ve got plenty of expansion options, too. Add up to 14 x EcoFlow 400W rigid solar panel per inverter for a maximum array size of 42 PV modules. That’s 16.8kW of solar charge potential.    

How Many Solar Panels Can You Connect to EcoFlow DELTA Pro Ultra?

All solar panels — and other photovoltaic modules like solar shingles — come with a rated power output that’s determined in a lab under Standard Test Conditions.  

Standard Test Conditions for Solar Panels

Condition TypeStandard Test ConditionReal-World Conditions
Solar Incident AngleAlways zero, irradiation beam always normal to the PV panel*Variable and depends on time, date, and site latitude. In the case of rooftop systems, roof orientation and inclination govern system capacity.
Solar IrradiationAlways equal to 1000 Watts/m²*Variable and depends on the time, date, and site latitude. Limited sunshine hours bound system capacity.
Ambient TemperatureAlways 25°C*Variable and depends on the time, date, weather condition, and site latitude. Higher ambient temperature degrades PV panel efficiency and reduces system output.
Air Mass Coefficient (AM)Always equal to 1.5*Variable and depends on the time, date, and site latitude. Higher AM with higher latitudes.
System Losses
(e.g., Wiring, Inverter)
Always Zero*Variable and depends on the design and location of PV panels, inverter, and grid meter.

*Cannot be achieved in real-world operation (Source: ResearchGate)

The maximum solar charge input of 1 x EcoFlow DELTA Pro Ultra Inverter is 5.6kW, and you can connect up to 3 x inverters together for a maximum of 16.8kW. That means you can connect up to 14 x EcoFlow 400W rigid solar panels per inverter. With 2 x inverters, you can connect 28, with 3 x inverters, you can add up to 42. PV modules for residential use generally top out at about 400W of rated power per unit, but there are many other rated power options available. For example, EcoFlow’s 220W bifacial portable solar panel or the 100W flexible solar panel that’s particularly handy for mounting on curved or irregular surfaces. EcoFlow DELTA Pro Ultra is also compatible with most other PV modules from other manufacturers. As long as you don’t exceed the maximum solar charge input, you can mix and match solar panels of different wattages and connect them in series or parallel. Just keep in mind that once you start mixing wattages and manufacturers, installation becomes more of a challenge. It pays to hire a professional for complex installations. At the very least, make sure you don’t exceed the maximum wattage, voltage, and amperage allowed by your solar inverter and balance of system.    

Is EcoFlow DELTA Pro Ultra a Portable Power Station?

Yes, EcoFlow DELTA Pro Ultra is portable, but it’s no lightweight. The inverter weighs 70 lbs (32.7kg), and the battery weighs in at 116.4 lbs (52.8kg) for a combined weight of just over 186 lbs (84kg). Before you say, “That’s not very portable!” consider the optional suitcase-style trolley. Considering its 6kWh storage capacity and 7.kW of AC output, EcoFlow is actually surprisingly compact.

  • Inverter: 27.2 x 18.9 x 8.4 in (69.1 x 48 x 21.3 cm)
  • Battery: 26 x 18 x 8 in (66. x 45.7 x 20.3 cm)

It’s easy to wheel around and perfect for an extended road trip. But you’re definitely not going to want to take it backpacking. 

If you need something easy to carry, consider one of EcoFlow’s RIVER 2 series of portable power stations and solar generators.

What Kind of Batteries Does EcoFlow DELTA Pro Ultra Use?

EcoFlow DELTA Pro Ultra uses industry-leading lithium iron phosphate (LFP/LiFePO4) batteries. LFP batteries have significant advantages over lead acid, sealed lead acid (VRLA, gel cell, AGM), nickel-cadmium, and traditional lithium-ion solar and home backup batteries. The primary benefits include:

  • Higher energy density
  • Greater depth of discharge
  • Longer cycle life (lifespan)
  • Wider range of operating temperatures
  • Faster charging times

Final Thoughts

We hope you’ve found the answers to at least some of your questions about EcoFlow DELTA Pro Ultra

If not, ask away in the comments or join our community and talk to real-life EcoFlow customers and our support team. 

You’ll find awesome members-only discounts there too!

EcoFlow is a portable power and renewable energy solutions company. Since its founding in 2017, EcoFlow has provided peace-of-mind power to customers in over 85 markets through its DELTA and RIVER product lines of portable power stations and eco-friendly accessories.

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