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Solar · EcoFlow

Solar panels for the EcoFlow DELTA Pro Ultra

Written by Ian Schneider·Solar & Off-Grid Tester

EcoFlow put the DELTA Pro Ultra's solar ports on the inverter, the box that rides on top of the battery, and gave them the voltage windows of a rooftop array. There are two. The high-PV port accepts 80 to 450 volts through MC4, the weatherproof plug on the back of nearly every rigid panel. The low-PV port accepts 30 to 150 volts through a socket of EcoFlow's own. Use one or both.

Both are string inputs, built for several panels wired end to end rather than one on a cable, and both have a floor. The EcoFlow NextGen 220W Bifacial reads 21.5 volts on its label. The Jackery SolarSaga 200W reads 22. Neither reaches 30 on its own, and most folding panels read about the same. On this station they go in series: the positive lead of one panel into the negative of the next, so the voltages add and the current stays at one panel's worth. The manual puts it as a total. Add up the string, and the sum has to land inside the window.

Together the two ports take 5600 W, and nothing we track fills that. The biggest set we can build, thirteen Anker SOLIX 440W Rigid panels, delivers 4118 W and has the battery full in about an hour and a half. None of the forty-one panels we track is over the limit. At the cabin I'd feed this from the roof, a string of rigid panels into the high-PV port, and keep the folding ones for the truck.

The door
30–450 V
Its width
5600 W
Plug
MC4 / Proprietary
Full battery, best case
~1.1 h
EcoFlow DELTA Pro Ultra portable power station
In the box, in EcoFlow's words: one Solar(MC4)-to-Low-PV Port Charging Cable. The high-PV cable is sold separately.

The door

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

Every panel we track, lined up by the voltage on its label. That number is the open-circuit voltage, Voc on the sticker, what a panel puts out with nothing connected to it. The black line is 450 V, the high-PV port's ceiling. No single panel gets anywhere near it. On this station the line is for the string. Add up the Voc of every panel wired in series, and keep the total under it.

The pale cap on each bar is the extra voltage a −10 °C morning adds, about 10%. On one panel it barely shows. On a long string it adds up the same way the panels do. EcoFlow's manual says so: panel voltage rises below 0 °C, and it advises against 6, 8 or 10 panels in series in the cold. My deck in Truckee sits below freezing most mornings from November on. That cap is the part I'd measure with the Fluke before trusting a long string.

Hover a bar for the panel's name. If you already own a panel, type its Voc below and it joins the line. The chart shows one panel; your string is that number times however many you wire together.

Swipe sideways for the whole line-up.

050100150200250300350400450500550volts, open-circuit+1++yours?450 V · the lintel30 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

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

Best overall

Anker SOLIX 440W Rigid Solar Panel

13 panels deliver 4118 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. 22 panels deliver 3088 W.

Check price at Eco-Worthy

Best to carry

BLUETTI 350W Solar Panel (PV350)

252 W from a 32.4 lb panel, the most delivered watts per pound.

Check price at BLUETTI

A day on solar

How long the DELTA Pro Ultra takes to charge on solar

A little over an hour. That is with the full 5600 W coming in. No set of panels we track delivers that much, so any array you can buy lands to the right of the tick.

A good day has 3 to 6 hours of sun that strong. A battery this size, 6144 Wh, changes the question from whether the sun lasts to whether the array is big enough. Where you live and what month it is decide how many of those days you get. 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 (5600 W) · full in 1.1 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

Thirty-one fit, eight of them EcoFlow's own. Eleven plug straight in on MC4; the rest want an adapter lead to MC4, named in the list where we know it. For each one: the cable, what a single panel delivers in good sun, and the most the Ultra will take from a set of them. The sets run from nine panels to twenty-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, 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 take to charge on solar?

At its 5600 W solar limit it refills in about 1.1 hours. More panel watts than that won't charge it any faster.

What adapter does the DELTA Pro Ultra need for solar?

None, if the panel's plug is MC4 or Proprietary: BLUETTI 350W, Anker SOLIX 440W Rigid, BLUETTI PV100 FX Flexible 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?

Yes. What decides it is the panel's voltage and plug, not the brand. 23 panels from Renogy, Jackery, BLUETTI, Anker SOLIX, Eco-Worthy and Rich Solar work with it, as long as the panel stays under 450 V on a cold morning and starts above 30 V.

The strongest single panels here are the Renogy 590W N-Type Bifacial (425 W delivered) and the Jackery SolarSaga 500 X (360 W delivered).

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

You have to. Its input starts at 30 V, so one panel alone won't wake it: wire 2 or more in series.

Wired in series, up to 9 BLUETTI PV100 FX Flexible panels fit under its 450 V limit, even on a -10°C morning. Series adds voltage; parallel adds current.

Past 5600 W delivered, more panels only help on cloudy days.

What is the DELTA Pro Ultra's solar input?

High-PV Input (high-PV input port, on the inverter): 80–450 V, up to 15 A, 4000 W. Low-PV Input (low-PV input port, on the inverter): 30–150 V, up to 15 A, 1600 W. 5600 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.