Renogy 220W Portable Solar Panel Review: Two in Series Fully Charge the EcoFlow DELTA 3

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The Renogy 220W portable solar panel folds into its own carry case and opens out into a full-size 220W panel, and two of them wired in series are a near-perfect match for the EcoFlow DELTA 3. The DELTA 3 accepts up to 500W of solar input, and a pair of these Renogy 220W Lightweight Portable Solar Suitcase panels in series delivers about 440W: close to the limit, with a little headroom.

It’s not a panel you buy once. On a 1kWh power station, one panel on its own does the job slowly, and the pair is what makes solar genuinely useful in a long power cut. That changes the maths on price, storage and setup compared with a single-panel solution.

Renogy 220W Portable Solar Panel Specs

• Max power: 220W (per panel)
• Open-circuit voltage: 23.6V
• Optimum operating voltage: 20.0V
• Optimum operating current: 11A
• Cell efficiency: 22.70%
• Unfolded dimensions (with handle): 1843 x 730 x 20mm
• Folded dimensions: 460 x 690 x 80mm
• Weight: 7.20kg per panel
• IP67-rated, fibreglass-reinforced construction
• Warranty: 3 years on materials and workmanship

Two Renogy 220W Portable Solar Panels in Series for the EcoFlow DELTA 3

The EcoFlow DELTA 3’s solar input takes up to 500W, at between 11 and 60 volts, with a current limit of roughly 13 to 15 amps depending on which spec sheet you read. Each Renogy 220W portable solar panel produces about 20 volts at 11 amps in full sun, and 23.6 volts with no load.

Wire two in series and the voltages add while the current stays the same: about 40 volts at 11 amps, or roughly 440W, with an open-circuit voltage of about 47 volts, safely under the 60-volt limit. That’s the setup that actually uses what the panels can give.

Wire two in parallel and it’s the current that adds instead: about 20 volts at 22 amps. That’s well over the DELTA 3’s current limit, so the power station caps what it takes and you’d see something nearer 260 to 300W, throwing away a third of what you paid for. For this pairing, series is the right way round.

Buying a single Renogy 220W portable solar panel still works, it just tops the DELTA 3 up more slowly. If you want solar to be a real answer to a multi-day power cut rather than a phone-charging bonus, this is a two-panel purchase.

Storing a Pair of Renogy 220W Portable Solar Panels

At 7.20kg each and folding down to 460 x 690 x 80mm, two of these together is a real amount of kit — roughly 14.5kg combined, needing proper storage space rather than a cupboard shelf. Worth factoring in before buying, particularly if space at home is already tight.

Wiring Two Panels in Series

Unfold both panels and set them facing the same direction at the same angle. In series, the whole string runs at the pace of the weaker panel, so one panel in shade drags the pair down: keep them both in clear sun, away from the shadow of a fence, tree or the house.

Each Renogy 220W Lightweight Portable Solar Suitcase has its own pair of MC4 leads. To join them in series, plug the positive lead of the first panel into the negative lead of the second. That leaves one spare positive and one spare negative, which go into an MC4-to-XT60 solar charging cable and then into the DELTA 3’s solar input. No Y-branch adapter is needed for series wiring.

Once it’s connected, the DELTA 3’s display and app show the combined incoming wattage. In UK sunshine you’ll rarely see the full 440W, because angle, cloud and temperature all knock real output below the rated figure, but a good summer day will still refill a 1kWh battery in a few hours.

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Pros and Cons

Pros

• Two Renogy 220W portable solar panels in series deliver about 440W, a near-perfect match for the EcoFlow DELTA 3’s 500W solar input
• Folds into its own carry case, so it stores flat and sets up in minutes
• IP67-rated, fibreglass-reinforced for genuine outdoor use
• 3-year warranty on materials and workmanship

Cons

• Best bought as a pair for the DELTA 3: one panel on its own charges it slowly
• Combined weight (~14.5kg) and folded size for two panels needs real storage space
• In series, shading one panel pulls down the whole pair, so placement matters
• Buying two at once is a bigger single purchase than most single-panel alternatives

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