Head-to-head test
EcoFlow RIVER 3 PLUS vs Anker SOLIX C300X
For $21 less than the Anker, the RIVER 3 PLUS doubles the output, doubles the surge, and doubles the solar input, then offers to grow past both, and the C300X's answer is two extra watt-hours of capacity and a faster USB-C port.
Written by Wenny ZhengUpdated
Portable Power Tester, Station Arena Test Desk
EcoFlow
RIVER 3 PLUS
1,863Power Score · Device Hub
$259.00 · direct from EcoFlow
Last checked 30 days ago. Prices move — check before you buy.
Anker
SOLIX C300X
1,638Power Score · Device Hub
$299.99 · direct from Anker
Last checked 6 days ago. Prices move — check before you buy.
Spec deltas
The RIVER 3 PLUS costs $279, undercuts the $300 Anker, and doubles it where it counts: 600W of output to the C300X's 300W, a 1200W surge to 600W, and 200W of solar input to 100W. The two hold nearly identical capacity, 286Wh against 288, so the Anker's headline number is a 2Wh lead, roughly ten seconds of a phone charge.
Doubled output is the whole story, because it changes what the unit can physically do. A 300W box like the C300X taps out before a microwave, a coffee maker, or a space heater even thinks about starting; the RIVER 3 PLUS's 600W inverter, with a 1200W surge, briefly runs exactly those loadsA3. Same size battery, twice the doorway to push it through.
The C300X isn't a bad unit, it's a well-built one aimed at a different job. Its 140W USB-C port beats the RIVER 3 PLUS's 100W, it's a pound and a half lighter at 9 pounds, and testers found it near-silent even under loadB4, a hair below the RIVER 3 PLUS's sub-30dBA2. If your world is laptops and phones in a quiet room, that's a real pitch. If you ever want to run an actual appliance, the doubled inverter settles it, and it costs less.
What the Numbers Reveal
Each conclusion stated first — the numbers behind it on one line, the full analysis below.
continuous output
That inverts the usual trade. You normally pay more for more power; here the RIVER 3 PLUS gives you double the continuous output and surge headroom and asks $21 less. The Anker's 2Wh of extra capacity can't buy back a 300W output deficit that decides whether a coffee maker runs at all.
RIVER 3 PLUS $279 vs C300X $300RIVER 3 PLUS runs 600W continuous and 1200W surge vs C300X 300W and 600WBoth hold about the same capacity, 286Wh vs 288Wh
Why it mattersAnyone who might plug in an appliance, not just electronics, should take the RIVER 3 PLUS and the savings.
Capacity
Because the PLUS starts 2Wh below the Anker, expansion isn't free headroom until you climb past 288Wh; the growth story only starts paying once you're adding capacity neither unit shipped with. So don't buy the PLUS for the expansion alone. Buy it for the doubled output, and keep expandability as the option you're glad exists laterA1.
RIVER 3 PLUS is expandable; the C300X is fixed at 288WhRIVER 3 PLUS base capacity is 286Wh, 2Wh under the C300X's 288WhThe engine raises a fixed-capacity flag against the C300X
Why it mattersExpansion is a real tiebreaker, but it's the inverter, not the growth path, that wins this.
weight
Stack all three and you get a marginally lighter, marginally quieter unit that charges a 16-inch laptop faster. Real for a specific desk-and-bedroom buyer, invisible to anyone who wants a load the 300W inverter can't start. None of the three closes a 300W output gap.
C300X USB-C is 140W vs the RIVER 3 PLUS's 100WC300X weighs 9 lb vs 10.4 lbC300X spec noise is 25dB vs 30dB
Why it mattersIf your use is electronics in a quiet room and never an appliance, the C300X's small edges are worth weighing; otherwise they're footnotes.
The specific dimensions that decide these two units — everything else is a tie.
PowerScore Breakdown
Selected because: 1881 vs 1666 tracks the doubled output/surge/solar; the composite and the price agree for once.
overall power score
PowerScore puts the RIVER 3 PLUS well clear, 1881 to 1666, and this time the composite and the price agree. The gap is output: 600W to 300W, a 1200W surge to 600W, and 200W of solar to 100W, all on the cheaper unit. The C300X claws back a little with a 140W USB-C port and a lighter body, but the score is measuring the thing you actually buy a power station to do, push watts, and the RIVER 3 PLUS pushes twice as many.
Growth Path
Selected because: Expansion gotcha fires; the honest read is the PLUS's first battery buys back the 2Wh the C300X already has.
solar input
The RIVER 3 PLUS is the only one of the two that grows; the C300X is a sealed 288Wh box, and the fixed-capacity flag the engine raises against it is fair. But read the growth edge honestly. The PLUS starts at 286Wh, 2Wh under the Anker, so your first expansion battery spends itself buying back capacity the C300X already includes before it adds anything newA1.
That doesn't make expansion worthless, it makes it a later-stage feature rather than a day-one win. If you know your needs will climb, adding capacity to the base you already own beats buying a second whole unit. If they won't, the two are close enough on capacity that this column is a tie, and the output gap decides everything anyway.
Lifetime Value
Selected because: cheaperToOwn is p1 again ($0.33 vs $0.35) on top of the lower sticker; reinforces the value verdict.
cost / lifetime kWh
The cheaper unit to buy is again the cheaper unit to own: $279 against $300, and $0.33 per lifetime kilowatt-hour to the C300X's $0.35. The margin is thinner than the sticker gap suggests, because the C300X's slightly larger battery spreads its cost over a hair more energy. But there's no version of this where you pay more for the Anker and come out ahead; it's pricier at the register and pricier per kilowatt-hour across the same five-year warranty.
Brand Trust
Selected because: Cross-brand: EcoFlow's breadth and community vs Anker's household-name trust and slipping SOLIX support.
EcoFlow's pitch is depth: the widest model range in portable power, the fastest charging, and a community that answers questions faster than any support line. The cost of that scale is an uneven support record and a 2025 DELTA Max recall on a different model. Anker sells trust it earned putting chargers in everyone's bag, plus InfiniPower cells and standout value per watt-hour, though SOLIX support is drifting toward scripted AI answers and firmware that quietly drops features. Neither should scare you off a sub-$300 unit; EcoFlow's ecosystem is simply the more useful one to fall back on.
Strengths & trade-offs
EcoFlow RIVER 3 PLUS
Strengths
- +Costs $41 less
- +Higher AC output
- +Faster solar charging
Trade-offs
- –No major technical downsides compared to rival.
Anker SOLIX C300X
Strengths
- +Lighter by 1.4 lb
- +Larger battery capacity
Trade-offs
- –No major technical downsides compared to rival.
Will It Power Your Gear?
Scenario math and per-appliance runtimes, modeled from the spec record.
Scenario verdicts
We ran the math on seven real-world scenarios. Here's which unit survives your actual life.
SCN-01 · 2 nights · needs 2,100Wh
Weekend Camping
Two nights off-grid with essential comfort
Neither unit
Neither unit covers this scenario's 2,100Wh: the RIVER 3 PLUS comes up 1,857Wh short (about 12% covered), the SOLIX C300X 1,855Wh (12%). This is well outside what either unit is for; the right answer here is a larger station, not a choice between these two.
Battery budget usedlower = more headroom
LOAD Phone Charger 15W×6h · LED Lights 40W×8h · Box Fan 75W×14h · CPAP Machine 40W×16h
SCN-02 · 8 hours · needs 1,645Wh
8-Hour Blackout
Keep the essentials running through a night without power
Neither unit
Neither unit covers this scenario's 1,645Wh: the RIVER 3 PLUS comes up 1,402Wh short (about 15% covered), the SOLIX C300X 1,400Wh (15%). This is well outside what either unit is for; the right answer here is a larger station, not a choice between these two.
Battery budget usedlower = more headroom
LOAD Fridge 150W×8h · Router + Modem 20W×8h · LED Lights (4 bulbs) 40W×6h · Phone Charger 15W×3h
SCN-03 · 8 hours · needs 320Wh
CPAP Overnight
Sleep therapy without interruption — the #1 medical use case
Neither unit
Neither unit covers this scenario's 320Wh: the RIVER 3 PLUS comes up 77Wh short (about 76% covered), the SOLIX C300X 75Wh (76%). Either gets you most of the way, so this is a scenario you plan around rather than one you should rule them out for.
Battery budget usedlower = more headroom
LOAD CPAP Machine 40W×8h
SCN-04 · 8 hours · needs 910Wh
Remote Workday
Full work day off-grid without power anxiety
Neither unit
A laptop, a monitor, and a phone for a workday sit well within both units' output, so this one comes down to the desk details. The C300X's 140W USB-C tops a 16-inch laptop faster and its fan is a touch quieter; the RIVER 3 PLUS answers with more total output you won't use here and a lower price. For a pure work-from-the-truck setup, the Anker's quiet and its port are the better fit, one of the few places it leans ahead.
Battery budget usedlower = more headroom
LOAD Laptop 60W×8h · External Monitor 30W×8h · Router + Modem 20W×8h · Phone Charger 15W×2h
SCN-05 · 4 hours · needs 670Wh
Tailgate Party
Game day power for the crew
Neither unit
Neither box has the capacity to carry a full tailgate on its own, but if you're running a blender, a speaker, and a warming tray at once, the question isn't capacity, it's output. The RIVER 3 PLUS's 600W inverter drives more of those at the same time than the C300X's 300W, which starts refusing the third thing you plug in. Same short runtime from both, more simultaneous load from the PLUS.
Battery budget usedlower = more headroom
LOAD Blender 400W×0.5h · LED TV (55") 80W×4h · Bluetooth Speaker 15W×4h · Phone Charger (×3) 45W×2h
SCN-06 · 24 hours · needs 4,685Wh
Van Life Daily
A full day of mobile living — the ultimate endurance test
Neither unit
Neither unit covers this scenario's 4,685Wh: the RIVER 3 PLUS comes up 4,442Wh short (about 5% covered), the SOLIX C300X 4,440Wh (5%). This is well outside what either unit is for; the right answer here is a larger station, not a choice between these two.
Battery budget usedlower = more headroom
LOAD Mini-Fridge 150W×24h · Laptop 60W×4h · Phone Charger 15W×3h · LED Lights 40W×5h · Fan 75W×8h
SCN-07 · an afternoon · needs 100Wh
Afternoon Off-Grid
Phones and a speaker at the park, beach, or campsite — the small-unit job description
Either unit
This is the job small stations are actually for, and both do it: the RIVER 3 PLUS finishes at 41% used, the SOLIX C300X at 41%. At this size the decider is what rides in the bag — 9 lbs for the SOLIX C300X against 10.4 for the RIVER 3 PLUS — and price, not the leftover watt-hours.
Battery budget usedlower = more headroom
LOAD Phone Charger (×2) 30W×2h · Bluetooth Speaker 10W×4h
The Load Test
RUNTIME = (Wh × 0.85) ÷ LOAD
None of the scenarios above exactly yours? Build it. Toggle what you'd plug in; both units are tested against the combined draw.
Essentials
Comfort & Convenience
High-Draw Appliances
Test duration
8h
Continuous draw
205W
Projected runtime
Dead heat — both run this 205W load for roughly 1.2h. Pick on price, weight, or ports.
Modeled from the spec record — same math as the tables below. Methodology
Runtime by appliance
Real-world runtime estimates for common appliances, modeled at 85% inverter efficiency.¹
Essentials
The basics you need runningscale 0–16.3hComfort & Convenience
Makes off-grid life actually enjoyablescale 0–3.3hHigh-Draw Appliances
These reveal the real limits¹ Runtime = (capacity × 0.85) ÷ appliance watts. Within each group, all bars share one time scale (the group's longest runtime), so lengths are comparable across appliances; identical runtimes collapse into a single blue/orange bar. Actual runtime varies with battery age, temperature, and simultaneous loads — see methodology.
Conclusion
July 18, 2026
Verdict: the RIVER 3 PLUS
This one isn't close. The RIVER 3 PLUS is the cheaper unit at $279 to the Anker's $300, and for the lower price it runs 600W to the C300X's 300W, surges to 1200W against 600W, and takes 200W of solar to 100W, all while holding within 2Wh of the same capacity, 286 to 288. It's also cheaper to own at $0.33 per lifetime kilowatt-hour against $0.35, and expandable if you outgrow it. The C300X answers with a 140W USB-C port to the RIVER 3 PLUS's 100W, a pound and a half less weight, and a slightly quieter spec at 25dB to 30. Those are real, but they don't touch doubled output. Unless the only thing you do is fast-charge a 16-inch laptop in a silent room, take the RIVER 3 PLUS and save the $21.
Editor-assigned confidence, based on cited owner research and spec analysis.
List prices as of July 18, 2026. The links below open EcoFlow's and Anker's current prices.
$259.00 · direct from EcoFlow
Last checked 30 days ago. Prices move — check before you buy.
or check the SOLIX C300X price$299.99 list
Written by Wenny Zheng, Portable Power Tester · Station Arena Test Desk · Updated July 18, 2026
Measured Data
Benchmark scores and the full spec record, side by side.
Benchmark scores
Not rated for both units (minimum threshold unmet): Solar Generator.
Full specifications
ᵈ Derived: price ÷ rated capacity. See the data behind our comparisons →
Comparison ToolAdd more power stations, side by sideOpen Tool →How these numbers are produced
Numeric verification
Every figure on this page traces to our spec database or arithmetic on it — no estimated numbers.
Owner claims
Statements about owner experience are cited to published reviews — see Sources & Research Notes below.
Runtime model
Runtime = (rated capacity × 0.85 inverter efficiency) ÷ device wattage. Solar recharge estimates assume panels deliver 70% of rated output. Cold weather, battery age, and stacked loads reduce real-world results.
Power Score
Computed from 14 published spec dimensions, weighted per use-case bench. Higher is better; a unit must meet a bench's minimum threshold to be rated.
See the full weight table and data sourcing on our methodology page →Class ranking (the star rating)
Each unit's star score is a category ranking, not customer reviews — no buyer opinions feed it. We score every station on size-independent quality (value, output, portability, endurance, ports, warranty, and more), then percentile-rank it against the other units in its capacity class, so a class-leading compact unit and a class-leading whole-home unit can both earn 5★. Here, RIVER 3 PLUS rates 5.0/5 (99th percentile of 22 Personal-class units), and SOLIX C300X rates 4.7/5 (81st percentile of 22 Personal-class units).
How the class ranking is computed →Test Notes & Caveats
Hidden gotchas and advantages we spotted that you won't find on the product page.
The expansion that buys back what you had
Flagging the C300X as fixed-capacity is fair, but the RIVER 3 PLUS's growth path comes with its own asterisk worth saying out loud. The PLUS starts at 286Wh, two watt-hours under the C300X, so the first expansion battery you add spends itself matching the Anker's capacity before it adds anything genuinely new. Expansion is a real long-term edge, but it's not free headroom from day one, and it's not the reason to pick this unit. The doubled output is.
Warranty: No Difference
Both units carry the same 5-year warranty, so coverage isn't a tiebreaker here.
Full record above — the Test Desk pick is the RIVER 3 PLUS.
Check RIVER 3 PLUS price →or check the SOLIX C300X priceOwnership Analysis
What happens after you buy — true cost of ownership, brand trust, and growth potential.
Lifetime value
Service lifeyears at one full cycle per day
Lifetime energy delivered
Cost per delivered kWh
│ warranty ends · Reaching the cycle rating means ~80% capacity remains — degraded, not dead.
Analyst note
Both units have similar long-term ownership costs ($0.3/kWh vs $0.35/kWh). The price difference is what you see on the sticker — neither is a hidden bargain or rip-off. One thing to know reading the table: both carry the same 3,000-cycle rating, so the lifetime rows are sticker price and capacity in disguise — the wear horizon is identical and decides nothing here.
Brand trust
EcoFlow
Ecosystem
The broadest lineup in the category and the most active release schedule, from RIVER-size units up to modular home systems, backed by the largest owner community around.
Support
US-based and genuinely hit-or-miss: many easy prepaid-label replacements, a stubborn minority of long waits and refurb-for-new swaps. A Costco or Amazon purchase is the safer return path.
Community
Largest community in the space — Reddit r/Ecoflow_community (~31K members), multiple Facebook groups, and an official community forum
App experience
Rated 4.6/5 iOS (~8,400 ratings) · 4.2/5 Android (~17,000 ratings)
Unique strength
Fastest-charging technology (X-Stream), deepest product ecosystem, and most active innovation cadence. At the very top of the range, the DELTA Pro Ultra platform stacks batteries and inverters into whole-home backup — a flagship path, not a line-wide feature.
Worth knowing
Home to the fastest charging in the class, with a 2025 DELTA Max recall on an unrelated model and no service once the warranty lapses.
Anker
Ecosystem
A focused SOLIX range leaning on Anker's mass-market charger reputation; smaller than EcoFlow's, but instantly familiar.
Support
Once the gold standard for painless replacements, now trending toward scripted AI first-contact and clumsy freight logistics on big units. The name still carries weight.
Community
Moderate — active Reddit (r/Anker, r/AnkerSOLIXCommunity) and growing. Benefits from Anker's massive consumer electronics brand awareness.
App experience
Rated 4.5/5 iOS (~1,100 ratings) · 4.3/5 Android
Unique strength
Parent brand trust from Anker's consumer electronics dominance. InfiniPower technology for long cycle life. Strong $/Wh value in the mid-size and larger units — the S2000, F2600 and C1000 are among the better buys per watt-hour in the catalog.
Worth knowing
InfiniPower longevity and some of the best value per watt-hour anywhere, dented by firmware updates that have removed features without notice.
Analyst note
EcoFlow is the specialist that will sell you anything from a RIVER to a whole-home stack and has the community to match; Anker is the trusted household name with sharper value and a support desk sliding off its old peak. For this pair the badges are a wash, and the RIVER 3 PLUS's hardware is the reason to choose.
Growth path
RIVER 3 PLUS
EXPANDABLESupports EcoFlow expansion batteries, so you can add capacity later without replacing the base unit — useful if your needs may climb past 286Wh.
Accepts up to 200W of solar. Limited to a single portable panel.
Adequate ports for most setups, but heavy users may want a power strip.
Expansion batteries are EcoFlow-specific. You're investing in the EcoFlow ecosystem.
SOLIX C300X
FIXED CAPACITYFixed at 288Wh, with no expansion — so size it for your needs up front rather than planning to add capacity later.
Accepts up to 100W of solar. Limited to a single portable panel.
Adequate ports for most setups, but heavy users may want a power strip.
Realistic full solar rechargeat 70% of rated panel output — see methodology
Analyst note
Don't read the RIVER 3 PLUS's expandability as a straight win here: it starts at 286Wh, below the SOLIX C300X's 288Wh, so a first expansion battery largely buys back capacity the SOLIX C300X already includes. It only pulls ahead if you'd grow past 288Wh — short of that, the SOLIX C300X's larger fixed capacity is the simpler value.
What Owners Report
Patterns from published owner reports and long-term reviews — every claim cited to its source below.
EcoFlow RIVER 3 PLUS
In the field the RIVER 3 PLUS reads as a small unit that punches up. Reviewers highlight the doubled hardware over the base RIVER 3, a genuine 600W inverter with a 1200W X-Boost and 200W of solar input, as the reason to step upA1. They also call its sub-30dB running genuinely remarkable, quieter than a library and than most refrigeratorsA2, and note that at about 10.4 pounds it stays easy to carry while briefly running a coffee maker, microwave, or space heaterA3. On LiFePO4 rated for 3,000 cycles, the estimate is roughly ten years before capacity slips to 80%A4.
“286Wh base, expandable to 572Wh (EB300) or 858Wh (EB600), with a genuine 600W inverter (1,200W X-Boost) and 220W solar input — twice the inverter and solar of the base RIVER 3.”
Sources
ecoflow.com · bestgeneratorsolar.com · thepowerpick.com · storagereview.com · phonearena.com · greenreviewshub.com
Anker SOLIX C300X
The C300X's field reputation is built on how it's built. Reviewers describe it as feeling premium in a way budget stations usually don't, with a carry handle that showed no wear or flex after dozens of trunk loadsB12. The app is the other bright spot: its most useful trick is over-the-air firmware and a usage history sharp enough to catch a fan drawing twice its expected wattageB10, though some users report a Bluetooth pairing dropout that blocks monitoring until they forget-and-repair the deviceB1. Its own reviewers flag the honest limits, wishing the 100W solar ceiling were higher and calling Anker's panels expensiveB6, and one owner reported a unit that wouldn't charge past 25%B2. As a 2026 release, the record here is expert hands-on rather than years of owner data.
“The unit was confirmed to shut itself off when charging very low-draw devices like headphones or a smartwatch — an intended power-saving cutoff rather than a defect, but one that catches owners off guard.”
Sources
teqclub.com · thesolarlab.com · backuppowerhub.com
Sources & Research Notes
Every owner claim in this report is traceable to a published source. The bracketed references above resolve here.
Recurring owner themes
- Expandable capacity, doubled inverter and solar over the base RIVER 3, remarkable sub-30dB quiet, and light weight are the praise. [RIVER 3 PLUS · 3 entries]
- Independent hands-on reviewers found the C300X near-silent at its rated 300W load, though one test noted the fan becoming noticeably audible under a heavier transient/overload draw. [SOLIX C300X · 2 entries]
- AC charging and UPS switchover both performed at or better than spec in hands-on testing — fast wall recharge and an imperceptible transfer that kept a computer, router, and CPAP running through a pulled plug. [SOLIX C300X · 2 entries]
- The most concrete owner-reported defects both sit in the app/charging pipeline: a Bluetooth pairing dropout that blocks monitoring, and a specific report of the battery refusing to charge past 25%. [SOLIX C300X · 2 entries]
- A1
“286Wh base, expandable to 572Wh (EB300) or 858Wh (EB600), with a genuine 600W inverter (1,200W X-Boost) and 220W solar input — twice the inverter and solar of the base RIVER 3.”
ecoflow.com / bestgeneratorsolar.com — RIVER 3 Plus review · 2026 · [positive]
- A2
“Sub-30dB operation is genuinely remarkable — quieter than a library and than most refrigerators.”
thepowerpick.com — RIVER 3 Plus review · 2026 · [positive]
- A3
“Weighs about 10.4 lbs and is highly portable; a small-format station that grows with you, able to briefly run a coffee maker, microwave, or space heater.”
storagereview.com / phonearena.com — RIVER 3 Plus review · 2026 · [positive]
- A4
“LiFePO4 rated for 3,000 charge cycles — around 10 years of everyday use before capacity drops to 80%.”
greenreviewshub.com / bestgeneratorsolar.com — RIVER 3 Plus review · 2026 · [positive]
- B1
“Users reported trouble connecting the C300X to the Anker app, which blocked monitoring power usage and changing settings; re-pairing by "forgetting" the device in Bluetooth settings and reconnecting through the app usually fixed it.”
teqclub.com — "Solving Common Anker C300X Problems" · unknown · [negative]
- B2
“My Anker solix c300x Portable Power Station will not accept charge more than 25%.”
teqclub.com — "Solving Common Anker C300X Problems" (quoted owner comment) · unknown · [negative]
- B4
“This unit is impressively quiet. Even with the internal fans running when we pushed it to its limits, the C300X makes virtually no noise.”
thesolarlab.com — "Anker C300X Power Station Review" · 2026 · [positive]
- B6
“The 100W solar input ceiling felt too low — the reviewer wished for 200W support — and called Anker's own solar panels expensive; a solar panel recognition delay was also noted on initial connection.”
thesolarlab.com — "Anker C300X Power Station Review" · 2026 · [negative]
- B10
“The app's most useful function was over-the-air firmware updates and historical usage data — the reviewer used the history to notice a portable fan was drawing twice the wattage expected.”
backuppowerhub.com — "Anker SOLIX C300X Review" · 2026 · [positive]
- B12
“The C300X feels premium in a way many budget power stations don't; the carry handle showed no wear or flex after dozens of trunk loads.”
backuppowerhub.com — "Anker SOLIX C300X Review" · 2026 · [positive]
Research compiled July 18, 2026.
Who Should Buy Which
Buy the RIVER 3 PLUS if you…
- →Anyone who might run an appliance: 600W continuous and a 1200W surge briefly start a coffee maker, microwave, or space heater the C300X's 300W can'tA3.
- →Solar chargers: 200W of input to the C300X's 100W refills it in half the sun.
- →Value buyers: $279 to $300, and cheaper to own, for the more capable unit.
- →Anyone whose needs might grow: the base takes expansion batteries, the C300X doesn'tA1.
Buy the SOLIX C300X if you…
- →Big-laptop owners in a quiet room: 140W USB-C to the RIVER 3 PLUS's 100W, and a near-silent fanB4.
- →Weight-sensitive carriers: 9 pounds to the RIVER 3 PLUS's 10.4, if that pound and a half matters more than output.
- →Buyers who value build feel: reviewers rate it a cut above the usual budget stationB12.
- →App-first users: the usage-history view is genuinely handyB10.
If neither fits
If you need to power a household through an 8-hour blackout or a weekend off-grid, neither finishes it; even the 600W RIVER 3 PLUS is a 286Wh battery, and those loads run past both. This is the tier for electronics, short appliance bursts, and CPAP backup, not whole-home runtime. Want that, and you're shopping a much larger class, not this one.
The Bottom Line
The RIVER 3 PLUS wins this going away. For $21 less than the C300X it runs twice the continuous output, twice the surge, and twice the solar input, holds within 2Wh of the same capacity, costs less to own, and can grow later. The Anker is the nicer-feeling, slightly lighter, slightly quieter box with a stronger USB-C port, and for a laptop-and-phone desk that's a fair pitch, just not one that answers doubled watts.
Buy the RIVER 3 PLUS and keep the $21, unless your entire use is fast-charging a big laptop in a silent room, in which case the C300X's small refinements are yours to enjoyB4.
Frequently Asked Questions
Answers drawn from the spec record and cited owner research.
Is the EcoFlow RIVER 3 PLUS or the Anker SOLIX C300X better?
The RIVER 3 PLUS, and it isn't close. It's cheaper at $279 to $300, and for the lower price it doubles the output to 600W, doubles the surge to 1200W, and doubles the solar input to 200W, on nearly the same capacity. The C300X wins on a 140W USB-C port, a slightly lighter body, and a quieter spec, but none of that offsets twice the inverter.
The C300X has more capacity, right?
By 2 watt-hours: 288Wh to the RIVER 3 PLUS's 286. That's about ten seconds of phone charging, not a difference you'll ever notice. And the PLUS can add expansion batteries later while the C300X is fixed at 288Wh, so even the capacity column tilts the other way over time.
Can the RIVER 3 PLUS run a microwave or coffee maker?
Briefly, yes. Its 600W inverter and 1200W surge handle short bursts from a coffee maker, microwave, or space heater, where the C300X's 300W taps out before they start. Neither runs those loads for long on a battery this size, but only one of them runs them at all.
Is the C300X worth $21 more than the RIVER 3 PLUS?
Only for a narrow buyer: someone who fast-charges a 16-inch laptop over USB-C, wants the lightest unit, and never plans to run an appliance. For that person the 140W port and 9-pound body earn it. For everyone else you're paying more for less output, and the RIVER 3 PLUS is the smarter buy.
Does the RIVER 3 PLUS expansion make it a clear win on capacity?
Not immediately. It starts at 286Wh, 2Wh below the C300X, so your first expansion battery mostly buys back capacity the Anker already has before it adds new headroom. Expansion is a genuine long-term edge, but the reason to buy the PLUS today is its doubled output, not its growth path.
Where to buy
EcoFlow RIVER 3 PLUSPick
$259.00
$259.00 · direct from EcoFlow
Last checked 30 days ago. Prices move — check before you buy.
Anker SOLIX C300X
$299.99
$299.99 · direct from Anker
Last checked 6 days ago. Prices move — check before you buy.
Prices may vary by retailer and are subject to change.