EcoFlow’s RIVER 2 Pro pairs a 768Wh LiFePO4 battery with an 800W inverter, but its solar port tops out at 220W. According to the RIVER 2 Pro user manual, that port accepts 11–50V at up to 13A, and EcoFlow quotes a full solar charge in roughly 4.5 to 9 hours. The manual also notes that the MC4-to-XT60 solar cable and the panels are sold separately, and that panel voltage must stay below 50V. On Oct. 17, 2026, EcoFlow’s U.S. store listed the RIVER 2 Pro at $389. This guide explains what those limits mean for choosing panels, how long charging really takes, and which setups make the most of the 220W ceiling.
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The EcoFlow RIVER 2 Pro specs below come from EcoFlow’s user manual and U.S. product page. We haven’t run our own solar test on this unit, so charge times beyond EcoFlow’s figures are estimates and labeled that way.
The RIVER 2 Pro’s Charging Inputs
| Input | Rating (EcoFlow manual) | Full charge, per EcoFlow |
|---|---|---|
| Solar (XT60 port) | 11–50V, 13A max, 220W max | About 4.5–9 hours |
| Car (same XT60 port) | 12V/24V, 8A max, 100W max | About 9 hours at the fastest |
| USB-C | 5–20V, 5A, 100W max | About 9 hours |
| AC wall (X-Stream) | 940W max (U.S. product page) | About 70 minutes |
The solar and car inputs share one XT60 port on the side of the unit, so you’ll use one or the other at a time. The battery itself is 768Wh, built from LiFePO4 cells that EcoFlow rates for 80%+ capacity after 3,000 cycles.
Why 220W Is the Number to Plan Around
A 768Wh battery on a 220W input means that even in perfect conditions, solar needs at least about 3.5 hours of full output to refill it. Real panels rarely deliver their full rating; a 200W panel typically produces something like 140–170W in good sun, by our estimate, which is why EcoFlow quotes 4.5 hours as the best case and 9 hours as a more modest day.
There are three limits working at once, and any one of them can be the bottleneck:
- Power: 220W. Extra panel wattage beyond this is wasted at midday, though it can help in the morning, late afternoon and under clouds.
- Current: 13A. A panel or parallel bank that pushes more than 13A is capped. Most single 100–200W panels stay under that.
- Voltage: 11–50V. Below 11V the port won’t charge. Above 50V you risk damaging the unit, which is why the manual warns to check panel voltage first.
For the voltage limit, the number on the panel label that matters is open-circuit voltage (Voc), which rises on cold mornings. Our guide to Voc, Vmp and Isc explains how to read a panel label.
Panel Setups Compared
The table uses typical specs for rigid or folding “12V-class” panels (around 22V Voc and 18V Vmp for a 100W panel; around 24V Voc for a 200W panel). Always check your own panel’s label.
| Setup | Voc (cold-morning margin) | Current | Within limits? | Notes |
|---|---|---|---|---|
| One 100W panel | ~22V | ~5.5A | Yes | Slow but simple; good for top-ups |
| One 160W folding panel | ~21–24V | ~8–9A | Yes | Good match for weekend camping |
| One 200W panel | ~24V | ~10–11A | Yes | Close to the 220W ceiling |
| Two 100W panels in series | ~44V (watch cold weather) | ~5.5A | Yes, with margin | Higher voltage means less loss on long cables |
| Two 100W panels in parallel | ~22V | ~11A | Yes | Better if one panel will be partly shaded |
| Three 100W panels in series | ~66V | ~5.5A | No | Over the 50V maximum; don’t do this |
| Two 200W panels in parallel | ~24V | ~21A | Current capped | Won’t damage it, but the unit only draws up to 13A |
Two 100W panels in series land around 44V open-circuit, which is under the 50V limit but leaves only a modest margin on a cold morning, when Voc can rise several percent. If your panels list Voc above about 23V each, wire them in parallel instead. See our series vs parallel wiring guide for the trade-offs.
How Long Solar Charging Takes
These are estimates for a 0–100% charge on a clear day, assuming real-world output of about 70–80% of the panel rating, and nothing plugged in.
| Panel wattage | Real output (estimate) | Approximate time, 0–100% |
|---|---|---|
| 100W | ~70–80W | ~10–11 hours (more than one day) |
| 160W | ~115–130W | ~6–7 hours |
| 200W | ~140–160W | ~5–5.5 hours |
| 220W+ (array at the cap) | ~200–220W at midday | ~4–4.5 hours, close to EcoFlow’s best case |
In winter, or with clouds, plan on roughly half of these figures per day. A single 100W panel won’t fill the RIVER 2 Pro from empty in one day of typical sun, but it can keep up with a small daily load like a router or phone charging.
A Daily Energy Budget
Thinking in watt-hours per day often makes more sense than charge time, especially on longer trips. Our estimates below assume about five hours of usable sun in summer and two to three in winter.
| Panel | Summer day (est.) | Winter day (est.) | What that covers |
|---|---|---|---|
| 100W | ~350–400Wh | ~150–220Wh | Phones, lights, a laptop, a few hours of a fan |
| 200W | ~700–800Wh | ~300–450Wh | A Starlink Mini for an evening plus a 12V fridge |
| 220W at the cap | ~800Wh+ | ~350–500Wh | About one full battery in summer |
If your daily use is under these numbers, the RIVER 2 Pro can run indefinitely on solar. A typical 12V compressor fridge, for example, uses somewhere around 300–600Wh a day depending on size and weather. Our refrigerator watts guide shows how to estimate your own.
Running Loads While Charging
The RIVER 2 Pro can power devices while it charges from solar. The net gain is simply solar input minus what you’re using. If a 200W panel produces 150W and a laptop and router draw 60W, the battery gains about 90W, so a full refill takes longer than the tables above. If the load exceeds solar input, the battery still drains, just more slowly.
Connecting Solar, Step by Step
- Check the panel’s Voc on its label. For series setups, add the panels’ Voc together and confirm the total stays well under 50V.
- Connect the panel’s MC4 leads to an MC4-to-XT60 adapter cable (sold separately, per EcoFlow).
- Plug the XT60 end into the RIVER 2 Pro’s solar/car input on the side.
- Angle the panel toward the sun and check the input watts on the screen or in the EcoFlow app.
- Re-angle the panel every hour or two for the best output.
Solar vs Car vs USB-C
The car input and USB-C are both capped at 100W, at around 9 hours to full, according to EcoFlow. A good 200W panel in strong sun beats both, and only the 940W wall input is faster. Since solar and car share one port, a common road-trip routine is car charging while driving and solar at camp. If you’re powering a Starlink Mini on the road, our guide to powering a Starlink Mini off-grid covers the options.
Picking a Panel for How You Travel
Car camping on weekends: one 160W to 200W folding panel is light enough to set out each afternoon and covers most of a weekend’s phones, lights and a 12V fridge, by our estimates. Pair it with car charging on the drive.
Van or truck with a roof: two fixed 100W panels in series keep cable losses low over a long roof-to-cabin run and stay under the 50V limit with typical panels. Use a fused, weatherproof cable entry.
Home backup during outages: two 100W panels in parallel on a patio or balcony are easy to angle and tolerate partial shade better. Combined with AC charging whenever the power is on, they stretch the 768Wh battery across a multi-day outage if loads stay modest. Our home battery backup guide covers outage planning.
Whichever you choose, the RIVER 2 Pro won’t use more than 220W, so spending on 400W of panels makes sense mainly if you often charge in shade, clouds or short winter days.
FAQ
What is the maximum solar input of the RIVER 2 Pro?
220W, at 11–50V and up to 13A, according to EcoFlow’s user manual.
How long does the RIVER 2 Pro take to charge from solar?
EcoFlow quotes about 4.5 to 9 hours with 220W of solar. With a single 100W panel, our estimate is more than one full day.
Can I connect a 400W panel to it?
Yes, if its voltage is under 50V. The unit will only draw up to 220W, so the extra wattage mainly helps in weak light.
Can I wire two 100W panels in series?
Usually yes. Two typical 100W panels add up to about 44V open-circuit, under the 50V limit. Check your panels’ labels, and switch to parallel if the total gets close to 50V.
Does it come with a solar cable?
No. EcoFlow’s manual says the MC4-to-XT60 solar charging cable and the panel are sold separately.
Can I charge from the car and solar at the same time?
No. They share one XT60 input port, so it’s one or the other.
Bottom Line
For the RIVER 2 Pro, a single 200W panel or two 100W panels hits the sweet spot: close to the 220W ceiling, well within the 13A and 50V limits, and enough to refill most of the 768Wh battery on a good summer day. If you’re also considering EcoFlow’s newer, lighter model, see our RIVER 2 Pro vs RIVER 3 Plus comparison.