Series vs Parallel: How to Connect Two Solar Panels to an EcoFlow Power Station

Connect two solar panels in series to add their voltages (current stays the same), or in parallel to add their currents (voltage stays the same). For most EcoFlow portable panels, series is the one to use, and EcoFlow’s manuals recommend it. The total must stay within your power station’s solar input limits.

The two rules

Every EcoFlow station’s solar input has a maximum voltage and a maximum current. The DELTA 3 manuals put it simply: total open-circuit voltage (Voc) within 60V, and total short-circuit current (Isc) within 15A (13A on the DELTA 3 Max).

So the question is never “which gives more watts”. Both do. The question is which one keeps you under the limits. In our checks we also keep at least 5% below the voltage limit (57V on a 60V port).

Worked example 1: two 220W panels on a DELTA 3

One EcoFlow 220W single-face panel is 21.5V Voc and 12.4A Isc.

• Series: 21.5 + 21.5 = 43V, current stays 12.4A. Under 57V and 15A: OK, 440W.
• Parallel: voltage stays 21.5V, current 12.4 + 12.4 = 24.8A. Over 15A: not OK.

The same goes for two EcoFlow 160W single-face panels: 42.6V and 9.1A in series (OK, 320W), but 18.2A in parallel (not OK). A third panel in series is too many: 63.9V for the 160W, 64.5V for the 220W.

Worked example 2: why two 400W Lightweight panels don’t work in series

One EcoFlow 400W Lightweight panel is 39.3V Voc and 12.2A Isc. It already uses most of a 60V port on its own.

• Series: 39.3 + 39.3 = 78.6V. That’s over 60V, the limit on every DELTA 3 model. Not OK.
• Parallel: EcoFlow says parallel is not recommended for its Lightweight panels because current gets too high (it would be 24.4A).

On stations with a 150V input, such as the EcoFlow DELTA Pro (11-150V), two 400W Lightweight panels in series do pass our check. On a DELTA 3 Plus or DELTA 3 2000 Air, use one 400W panel per port.

Worked example 3: the 125W bifacial panel goes parallel

The EcoFlow 125W bifacial panel works the other way round: high voltage (50V Voc), low current (3.2A Isc). EcoFlow PH calls it a “50V design for parallelling”.

• Series: two make 100V. Not OK on a 60V port.
• Parallel: four make 50V and 12.8A. OK on every DELTA 3 model, for 500W.

On the DELTA 3 Max (13A), four still pass on the standard figure, but the bifacial back-side current (13.6A) would exceed 13A, so three is the cautious choice there.

Worked example 4: low-voltage RIVER stations

RIVER 2 and RIVER 3 inputs accept only 11-30V. Two NextGen panels in series (about 43V) are too high, and EcoFlow’s manuals warn to stay under 30V to avoid damage. The 125W panel (50V) must not go on them at all.

Cables for each method

• Series, MC4 panels (160W, 220W, 400W rigid): the MC4 leads join male to female. Use EcoFlow Solar Extension Cables if the leads are too short.
• Series, Lightweight panels (built-in XT60): EcoFlow says a series cable is sold separately. We haven’t identified the exact cable, so ask EcoFlow PH before buying.
• Parallel, MC4 panels: EcoFlow’s Solar Parallel Connection Cable, sold separately.
• Parallel, 125W bifacial: panels daisy-chain with their own XT60W leads.

EcoFlow PH’s Lightweight FAQ recommends series between panels of the same model, and every pair in our checks is two identical panels. Our connector guide explains which plug goes where.

These are portable, plug-in panels the owner can set up following the manual. Wiring panels into a house, a breaker panel, the roof or the grid needs a licensed electrician (PEE) and an LGU electrical permit.

What to buy

• 2 × EcoFlow 220W single-face on Lazada (series pair for any DELTA 3)
• 2 × EcoFlow 160W single-face on Lazada or on Shopee
• Up to 4 × EcoFlow 125W bifacial on Lazada or on Shopee (parallel)

Check today’s price. For your model’s exact limits, see the DELTA 3 guide, the DELTA 3 Max guide, or use the which EcoFlow quiz.

Bottom line

Add up the volts for series and the amps for parallel, and compare with your station’s limits. On a 60V, 15A DELTA 3, two 220W panels in series work and two 400W Lightweight panels in series don’t.