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Solar · EcoFlow

Solar panels for the EcoFlow DELTA Pro Ultra X

Written by Ian Schneider·Solar & Off-Grid Tester

The DELTA Pro Ultra X takes solar the way a house does. Two PV ports, both on the inverter, each accepting 80 to 500 volts through MC4, the click-lock weatherproof connector every rigid panel ships with. Between them they take 10000 W. A string at 500 volts can kill you, and EcoFlow's manual wants the PV switch off before any cable goes in or comes out.

Start at the floor. 80 volts is more than any panel we track puts out alone. The tallest one, Renogy's 590 W bifacial, reads 52.63 on its label, and most folding panels read in the twenties. So panels go in series, the plug of one into the socket of the next, and their voltages add. The chain grows until the total clears the floor. There is no low-voltage door on this inverter. The DELTA Pro Ultra had one. The X doesn't.

The battery is 12288 Wh, and nothing we track fills the input. The biggest set we can build, twenty-two Anker SOLIX 440W Rigid panels, delivers 6970 W and has the battery full in a shade under two hours. Twenty-two panels is a roof. At the cabin that is where I'd put them, and I'd have the Fluke on the string and the PV switch off before any of it went near the inverter.

The door
80–500 V
Its width
10000 W
Plug
MC4
Full battery, best case
~1.2 h
EcoFlow DELTA Pro Ultra X portable power station
The manual publishes no in-the-box list, but it does mention one thing in the package: an MC4 disconnect tool, for prying the cover off the PV port.

The door

Every panel we track, lined up at the DELTA Pro Ultra X's solar input

Every panel we track, stood in a line by the voltage on its label. That number is Voc, the open-circuit voltage, what a panel reads with nothing connected. The black line is 500 V, and no bar comes close. The chart shows one panel at a time. The port sees the chain. Count the panels in your string, multiply, and compare that total with the line.

The chart leaves out the floor, 80 V, and on this station the floor does more work than the ceiling. Every bar sits under it. The chain exists to climb over it. The pale cap on each bar is the extra voltage a −10 °C morning adds, about 10%. One cap is a sliver. A chain of caps is the same 10% of a much taller number, so a string built to sit just under the ceiling in July can sit over it in January. My deck in Truckee spends most winter mornings well below freezing. I'd size the string for those mornings and let summer have the margin.

Hover a bar to see which panel it is. If you already own panels, type one's Voc in the box and it stands in the line with the rest. Then do the multiplication for your string, because the chart won't.

Swipe sideways for the whole line-up.

050100150200250300350400450500550600650volts, open-circuit+1++yours?500 V · the lintel80 V · the step

Hover or tap a bar for the panel’s name and its verdict.

  • Fits through the door
  • Too tall
  • Extra height on a −10 °C morning
  • Maker prints only the operating voltage; the real height is above the dashes
  • 1Our pick: Anker SOLIX 440W Rigid

What we'd buy

The best solar panel for the DELTA Pro Ultra X

Picked by the numbers on this station, not by brand.

Best overall

Anker SOLIX 440W Rigid Solar Panel

22 panels deliver 6970 W, and it plugs straight in.

Check price at Anker

Best value

Eco-Worthy 195W N-Type 18BB Bifacial Solar Panel (GW-L02M195NTM)

About $0.93 for every watt it actually delivers here. 32 panels deliver 4492 W.

Check price at Eco-Worthy

A day on solar

How long the DELTA Pro Ultra X takes to charge on solar

The tick sits just past the one-hour mark, and it assumes the full 10000 W arriving at once. Nothing we track gets there. The tick is the inverter's own limit. Any array you can actually buy lands to the right of it, and the list below says how far, panel by panel.

A good day gives 3 to 6 hours of sun that strong. With 12288 Wh behind the ports, the sun is never the problem. The size of the array is. Where you live and what month it is decide how many of those days you get, and the system builder works that out for your state.

a good day's sun: 3 to 6 h0 h1 h2 h3 h4 h5 h6 hInput full (10000 W) · full in 1.2 h

Hours of good sun, from empty. Where you live and the month decide how many of those a day gives; the system builder works it out.

Every panel that fits

Solar panels compatible with the DELTA Pro Ultra X

Thirty-one fit, and eight of them are EcoFlow's. Eleven arrive with MC4 on the end and plug straight in. The rest end in a barrel plug, an Anderson or an XT60 and want an adapter lead to MC4, named where we know it. For each panel: the cable, what one delivers in good sun, and the biggest set the Ultra X will take, which runs from sixteen panels to thirty-two. Sorted by delivered watts.

Own a panel that isn't in the line-up?

Type its voltage into the door chart above for the height test, then put the rest of the label into the panel checker, already set to the DELTA Pro Ultra X, for current and plug too. Or build the whole system to see how it keeps up where you live.

The plain answers

How long does the DELTA Pro Ultra X take to charge on solar?

At its 10000 W solar limit it refills in about 1.2 hours. More panel watts than that won't charge it any faster.

What adapter does the DELTA Pro Ultra X need for solar?

None, if the panel's plug is MC4: Anker SOLIX 440W Rigid, BLUETTI PV100 FX Flexible, BLUETTI SP100L and 8 others plug straight in.

The cables the other panels need: DC8020 to MC4 (4 panels), Anderson to MC4 (3 panels), DC5521 to MC4 (2 panels) and XT60 to MC4 (1 panel).

10 panels don't have a named plug from their maker, so check the lead before you buy a cable.

Can you use non-EcoFlow solar panels with the DELTA Pro Ultra X?

Yes. What decides it is the panel's voltage and plug, not the brand. 23 panels from Anker SOLIX, BLUETTI, Eco-Worthy, Jackery, Renogy and Rich Solar work with it, as long as the panel stays under 500 V on a cold morning and starts above 80 V.

No single panel starts it; they go in series. The strongest setups here are 22 Anker SOLIX 440W Rigid panels (6970 W delivered) and 16 Renogy 590W N-Type Bifacial panels (6796 W delivered).

Can you connect two solar panels to the DELTA Pro Ultra X?

You have to. Its input starts at 80 V, so one panel alone won't wake it: wire 3 or more in series.

Wired in series, up to 10 BLUETTI PV100 FX Flexible panels fit under its 500 V limit, even on a -10°C morning. Series adds voltage; parallel adds current.

Past 10000 W delivered, more panels only help on cloudy days.

What is the DELTA Pro Ultra X's solar input?

PV input port 1 (PV circuit one): 80–500 V, up to 15 A, 5000 W. PV input port 2 (PV circuit two): 80–500 V, up to 15 A, 5000 W. 10000 W across all inputs together.

Input limits from EcoFlow's documents, checked 2026-09-18 (source). Delivered watts assume 72% of the panel's rating in good sun.