Head-to-head test
EcoFlow RIVER 2 vs BLUETTI AC50B
Ninety dollars settles this: the AC50B covers a CPAP night, the RIVER 2 gets about two-thirds of the way there, and the bigger box is somehow the cheaper one per watt-hour you'll ever pull out of it.
Full profiles: EcoFlow RIVER 2 → · BLUETTI AC50B →
Written by Wenny ZhengUpdated
Portable Power Tester, Station Arena Test Desk
$209.00 · direct from EcoFlow
Last checked 20 days ago. Prices move — check before you buy.
$399.00 · direct from BLUETTI
Last checked 1 day ago. Prices move — check before you buy.
Spec deltas
Buy the AC50B. It's $399 against $209, and that $190 buys the 192Wh separating 256 from 448, which works out to about 47 cents a watt-hour. That is less than either unit charges for the watt-hours already inside it: 74 cents on the RIVER 2, 62 on the AC50B. The cheap one is the expensive energy.
The arithmetic isn't the reason, though. The reason is the single load profile on this page that either box can actually cover. A CPAP night asks for 320Wh. Take the usual 15% inverter cut and the RIVER 2 has about 218Wh to give (256 x 0.85) while the AC50B has about 381Wh (448 x 0.85). One of those numbers is bigger than 320.
The RIVER 2's case is weight and wall speed. 7.8 pounds against 14.8, and about an hour to full from an outlet where the AC50B wants roughly threeA2B3. If you carry this thing further than the trunk of a car, that's a real argument. For everyone else, those 7 pounds are simply what 192 extra watt-hours weigh.
What the Numbers Reveal
Each conclusion stated first — the numbers behind it on one line, the full analysis below.
Capacity
The AC50B is also the quieter unit by 5 dBA, and reviewers already flag the RIVER 2 as noticeably louder under loadA1. So for the one buyer whose night either of these boxes could plausibly cover, the same unit is both the one that reaches sunrise and the one that doesn't wake you at 3 a.m. arguing with its own fan. Those two qualities usually trade against each other. Here they don't.
RIVER 2: 256Wh. AC50B: 448Wh.CPAP Overnight profile draws 320Wh.Engine coverage: the night is 147% of the RIVER 2's usable pool and 84% of the AC50B's.Noise: 50 dBA on the RIVER 2, 45 dBA on the AC50B.
Why it mattersIf a CPAP is why you're shopping, the $190 stops being optional and starts being the entire purchase.
Typical price
Because the two share a cycle rating, that capacity gap compounds across the whole life of the battery instead of just the first charge. Three thousand cycles on 448Wh banks 1,344 kWh; the same 3,000 cycles on 256Wh banks 768. That's the mechanism behind 21 cents per lifetime kilowatt-hour against 25, and it means the shopper protecting their wallet by taking the $209 unit is paying a premium rate for the privilege.
Prices: $209 and $399, a $190 gap.Capacities: 256Wh and 448Wh, a 192Wh gap.Sticker rates: 74 cents per Wh and 62 cents per Wh.Both rated 3,000 cycles: 768 kWh of lifetime energy against 1,344 kWh.
Why it mattersAnyone treating $209 as the frugal choice should look at what they're paying per watt-hour before they call it that.
continuous output
The 7 pounds you save comes bundled with everything else that got smaller. The RIVER 2's inverter tops out at 600W of peak, and on the tailgate profile that ceiling is low enough that it can't even start the biggest thing you'd plug in, where the AC50B can. Capacity decides how long something runs. The inverter decides whether it runs at all, and that's the part the scale doesn't tell you.
Weights: 7.8 lbs and 14.8 lbs.Capacities: 256Wh and 448Wh.Continuous and peak output: 300W / 600W against 700W / 1,000W.Tailgate Party: the RIVER 2 can't start the peak load, the AC50B can.
Why it mattersTake the RIVER 2 for weight only if you're walking with it and running small loads; otherwise those 7 pounds are buying capability, not costing you convenience.
solar input
So the recharge argument isn't about which unit is faster, it's about where you plug in. Off-grid, the AC50B's larger battery costs you nothing in refill time because its solar input scaled with it. At home between short trips, the RIVER 2's hour is a genuine daily convenience, and the only way to buy it back on the AC50B is the Turbo chargerB3.
RIVER 2 refills from a wall outlet in about 60 minutesA2.AC50B takes about 3 hours standard, 1.25 hours with the optional 480W Turbo charger, 0-80% in 45 minutesB3.Solar input: 110W against 200W.
Why it mattersIf your recharge is a wall socket and you're usually in a hurry, that's the one live reason to take the RIVER 2, or to budget for the AC50B's Turbo charger up front.
The specific dimensions that decide these two units — everything else is a tie.
Runtime: Will It Power Your Gear?
Selected because: 448Wh against 256Wh is the only difference here that changes an outcome, and the outcome it changes is a 320Wh CPAP night.
continuous output
Two hundred and fifty-six watt-hours reads like plenty until you subtract the inverter's cut. Call it 218Wh you can actually pull from the RIVER 2 and 381Wh from the AC50B, and the question stops being how much bigger and becomes which side of 320 each one lands on. The AC50B lands above it.
Neither box runs anything for long at full tilt, and it's worth being blunt about that. Ask the RIVER 2 for its whole 300W and 256Wh is gone in about an hour (256 / 300). Ask the AC50B for its whole 700W and 448Wh is gone in about half that (448 / 700). These are top-up boxes. The AC50B is just a bigger top-up box that can start heavier things.
Your Life, Your Pick
Selected because: Five of the six load profiles are too big for both boxes. The sixth is why one of them costs $190 more.
Five of the six profiles on this page laugh at both units. Van life wants 4,685Wh. A weekend of camping wants 2,100Wh. An eight-hour blackout wants 1,645Wh. The larger of these two boxes holds 448Wh. There is no reading of this comparison in which either unit is your outage plan, and a page that implies otherwise is selling you something.
The CPAP night is the only profile that discriminates, at 320Wh, and it goes to the AC50B. Watch the tailgate row on the way past, though. Neither unit covers the party's 670Wh, but only one of them can start the peak load at all, and it isn't the RIVER 2. When both units fail a scenario, how they fail still tells you something.
Lifetime Value
Selected because: 21 cents per lifetime kilowatt-hour against 25: the more expensive unit is the cheaper energy.
cost / lifetime kWh
Twenty-one cents a kilowatt-hour against twenty-five. Both are cheap enough that neither will ever be the reason you regret this purchase, and that's the honest reading of this section. The direction is what surprises people: the bigger sticker buys the cheaper energy, because the same 3,000 cycles move 1,344 kWh through the AC50B and 768 kWh through the RIVER 2.
One number here genuinely favors the RIVER 2, and it's the annual one. $38 a year across the five-year warranty against $56. If your budget is a monthly figure rather than a total, that's a real argument and not a foolish one. It's just an argument about cash flow rather than value.
Portability & Form Factor
Selected because: 7.8 lbs against 14.8 lbs is the RIVER 2's strongest argument, and worth weighing before you spend the $190.
weight
Seven pounds is the RIVER 2's entire case, and it's a strong one for exactly one buyer: the person carrying this somewhere a car can't reach. 7.8 lbs is a grab-it-off-the-shelf, hold-it-in-one-hand-while-you-open-the-door weight. 14.8 lbs is still one-handed, but you'll put it down when you get there, and you'll notice the stairs.
What the RIVER 2 doesn't win is density: about 33 watt-hours per pound (256 / 7.8) against about 30 (448 / 14.8). Close enough to call even. You aren't paying a portability tax for the AC50B's capacity, you're just carrying it, which is a different complaint and a much smaller one.
What the Specs Don't Tell You
Selected because: Noise, surge ceiling and switchover speed all lean one way; the warranty is a dead heat at five years each.
The noise gap is small on paper and large in a bedroom: 45 dBA against 50. It compounds, too. Any given load is a smaller fraction of the AC50B's 700W inverter than of the RIVER 2's 300W, so the bigger unit spends more of its life loafing and less of it with the fan up. Reviewer reports of the RIVER 2 running loud under load are consistent with what the spec sheet already saysA1.
The surge card is the one that flatters the RIVER 2, and it shouldn't decide anything. Doubling 300W to 600W is a 2x multiple, and that multiple is a genuine sign of a well-built inverter; the AC50B only stretches 700W to 1,000W. But nothing you plug in knows the ratio. It knows whether the box will hand it 1,000W or 600W. Ratio is a quality tell. Ceiling is what starts the appliance.
The rest of the cards are quieter. The warranty is five years each, a flat tie. The UPS row is 20 milliseconds against 30, and since both are standby switches the power blinks either way, just for a shorter beat on the AC50B. Treat that one as a tiebreaker, not a reason.
Strengths & trade-offs
EcoFlow RIVER 2
Strengths
- +Costs $190 less
- +Lighter by 7 lb
Trade-offs
- –No major technical downsides compared to rival.
BLUETTI AC50B
Strengths
- +Larger battery capacity
- +Higher AC output
- +Faster solar charging
Trade-offs
- –Substantially more expensive (+$190) than the RIVER 2.
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 2 comes up 1,882Wh short (about 10% covered), the AC50B 1,719Wh (18%). 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 of these is an outage plan. The profile wants 1,645Wh; the AC50B falls short by more than four times over and the RIVER 2 by more than seven. What they will do is keep phones charged, a router alive and a couple of lamps on, which is a perfectly good thing to want. Just don't buy either one expecting the refrigerator to see morning.
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
AC50B
This is the one night on the page either box could plausibly cover, and only one of them does. The AC50B has about 381Wh of usable capacity against the 320Wh the profile asks for. The RIVER 2 has about 218Wh, which gets you roughly two-thirds of the way to morning. It's also the quieter unit at 45 dBA against 50, so the same box wins both specs that matter to someone sleeping an arm's length from it.
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
Neither unit covers this scenario's 910Wh: the RIVER 2 comes up 692Wh short (about 24% covered), the AC50B 529Wh (42%). 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 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 covers the party's 670Wh, so plan on running things in shifts whichever one you bring. The difference is upstream of capacity: the AC50B can start the peak load and the RIVER 2's 600W ceiling can't, which means the biggest thing you plug in settles the evening before the battery gets a vote.
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 2 comes up 4,467Wh short (about 5% covered), the AC50B 4,304Wh (8%). 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 2 finishes at 46% used, the AC50B at 26%. At this size the decider is what rides in the bag — 7.8 lbs for the RIVER 2 against 14.8 for the AC50B — 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
For this load: AC50B runs 1.9h vs 1.1h.
$399 list · direct from BLUETTI
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 0–25.4hComfort & Convenience
Makes off-grid life actually enjoyablescale 0–5.1hHigh-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
August 1, 2026
Verdict: the AC50B, on Power Score margin
Take the BLUETTI AC50B at $399. It holds 448Wh against the RIVER 2's 256, hands an appliance 1,000W of peak against 600W, pulls 200W of solar against 110, runs 5 dBA quieter, and costs 21 cents per lifetime kilowatt-hour against 25. That last one is the tell: the box with the bigger sticker is the cheaper energy. The RIVER 2 wins two things and both are real. It's 7 pounds lighter, and it goes wall-to-full in about an hour where the AC50B wants roughly three on its standard chargerA2B3. Buy the RIVER 2 if you carry your power station on foot, or if you top up indoors against a clock. Everyone else should spend the $190. One thing to know going in: BLUETTI's support desk is the weakest part of this purchase, so buy direct from BLUETTI rather than a third-party seller and keep the receipt clean.
Editor-assigned confidence, based on cited owner research and spec analysis.
List prices as of August 1, 2026. The links below open EcoFlow's and BLUETTI's current prices.
$399.00 · direct from BLUETTI
Last checked 1 day ago. Prices move — check before you buy.
or check the RIVER 2 price$209.00 list
Written by Wenny Zheng, Portable Power Tester · Station Arena Test Desk · Updated August 1, 2026
Measured Data
Benchmark scores and the full spec record, side by side.
Benchmark scores
Not rated for both units (minimum threshold unmet): UPS, Solar Generator, Tailgating.
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 2 rates 3.9/5 (33rd percentile of 22 Personal-class units), and AC50B rates 4.6/5 (76th 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.
Five decibels, measured where you sleep
45 dBA against 50. On a spec sheet that's a rounding error; in a quiet bedroom at 3 a.m. it's the difference between a fan you sleep through and one you lie there listening to. It compounds, as well. Any given load is a smaller fraction of the AC50B's 700W inverter than of the RIVER 2's 300W, so the bigger unit loafs where the smaller one works.
The better ratio isn't the better inverter
The RIVER 2 doubles on startup, 300W to 600W, and a clean 2x multiple is what a well-designed inverter looks like. The AC50B only stretches from 700W to 1,000W. Then you go to plug something in, and the motor doesn't care about the multiple. It cares whether the box can hand it 1,000W or 600W. Ratio is a quality tell. Ceiling is what starts the appliance.
Twenty milliseconds against thirty
Both of these are standby switches, not true online UPS units, so the power does go away for a beat before the battery picks it up. The AC50B's beat is 20 milliseconds and the RIVER 2's is 30. A lamp or a router will never know the difference. Take it as a tiebreaker on an otherwise even call, not as a reason to spend money.
A dead heat, then the arithmetic
Five years each. Nothing to choose, and no one should pretend otherwise. What differs is what you paid for those years: $38 annually on the RIVER 2 against $56 on the AC50B. That's the one framing on this whole page that flatters the smaller unit, and it holds right up until you remember which of the two holds 448Wh.
RIVER 2: Noise Level Not Disclosed
The AC50B publishes its noise level (45dB); the RIVER 2 doesn't publish one. That isn't evidence the RIVER 2 is louder — it means there's no figure to hold it to, and no way to compare the two on this without hearing them. If you're buying for a bedroom, a CPAP, or an apartment, treat the AC50B's 45dB as the only published number on the table — a spec-sheet figure, not a measurement — and look for hands-on reports of the RIVER 2 before deciding.
Ownership 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 ($0.27/kWh vs $0.3/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
Largest in portable power — 12-15 models across DELTA Pro, DELTA 3, and RIVER 3 series, plus solar panels and smart home panels
Support
EcoFlow answers a US phone number, which is worth something at 9 p.m. on a holiday weekend. Reports are genuinely split all the same: prepaid return labels and quick swaps for some owners, long waits and refurbished replacements for others. Buying through a retailer with its own return window is the cheap insurance.
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
The deepest lineup in portable power and the fastest charging technology in it. If you expect to add panels or a second unit later, you're buying into the largest ecosystem in the category and the most active community to ask questions in.
Worth knowing
Tested subscription paywalls for advanced app features in early 2025 before community backlash paused the plan. No parts or service offered out of warranty.
BLUETTI
Ecosystem
One of the broadest lineups — 15-20+ models from budget (AC2A) to flagship portable (Apex 300, 2764.8Wh). Includes specialized products: vehicle solar hubs, sodium-ion cold-weather units, and balcony storage systems.
Support
This is where the AC50B costs you. BLUETTI's support is the most inconsistent in the category, heavily email-based with China timezone delays, and outcomes range from smooth and fair to weeks of runaround. The practical hedge is to buy direct from BLUETTI rather than a third-party seller, because claims go better when there's one name on the receipt.
Community
Active and growing — Reddit r/bluetti has a dedicated community. Second-largest after EcoFlow in engagement.
App experience
Rated 4.5/5 iOS and Android — tied for best app experience in the category. V3.0 UI redesign was well-received.
Unique strength
BLUETTI's whole argument is watt-hours per dollar, and the AC50B is that argument in its smallest form. The LFP standardization runs the full lineup, so the cell chemistry in this $399 box is the same one holding up their flagships.
Worth knowing
Customer support inconsistency is the #1 risk factor. Older/discontinued units may become unrepairable — no spare parts policy for some models. Some reports of erratic communication from support agents.
Analyst note
EcoFlow is the safer relationship and BLUETTI is the better box. That's this page in one line. If you're the sort of buyer who wants a phone number to call when something goes wrong, weight EcoFlow's support column heavily and accept the RIVER 2's smaller battery as the price of it. Everyone else buys the AC50B direct from BLUETTI and files the receipt somewhere they'll find it.
Growth path
RIVER 2
FIXED CAPACITYFixed at 256Wh, with no expansion — so size it for your needs up front rather than planning to add capacity later.
Accepts up to 110W of solar. Limited to a single portable panel.
Limited ports. You'll likely need a power strip or splitter.
AC50B
FIXED CAPACITYFixed at 448Wh, with no expansion — so size it for your needs up front rather than planning to add capacity later.
Accepts up to 200W of solar. Limited to a single portable panel.
Limited ports. You'll likely need a power strip or splitter.
Realistic full solar rechargeat 70% of rated panel output — see methodology
Analyst note
Neither expands, and that's no knock on either — each is a complete unit at a fixed size. Buy the capacity that covers your needs now (the AC50B gives you the larger ceiling); you can't add to either later.
What Owners Report
Patterns from published owner reports and long-term reviews — every claim cited to its source below.
EcoFlow RIVER 2
Field coverage on the RIVER 2 is thin and mostly comparative, written against the newer RIVER 3 rather than by long-term ownersA1A2A3. What exists is consistent. It's the older, cheaper unit on the same core platform, 300W of output and LiFePO4 cells and roughly an hour to full, and it's still treated as a proven budget pick rather than a compromiseA2.
The recurring complaint is noise: reviewers describe it as noticeably louder under load than the RIVER 3A1. The most useful line anyone writes about it is that for strictly indoor use where every dollar counts it remains a reasonable choice, while acknowledging you're giving up the newer unit's waterproofing, faster UPS and quieter operationA3.
“Shares the same core platform as the RIVER 3 — 300W output, LiFePO4 chemistry, and roughly 60-minute fast charging — and remains a popular, proven budget small-format unit.”
Sources
backuppowerhub.com · ecoflow.com · versus.com
BLUETTI AC50B
The AC50B reads well in the write-ups, and they all point at the same thing: a genuinely portable sub-15-pound box with a long-cycle LFP pack and 700W of output at a price that's easy to justifyB1B2. Reviewers frame that battery as good for years of reliable service rather than a season or twoB1.
The charging note is the one to plan around. About three hours to full on the standard charger, dropping to 1.25 hours with the optional 480W Turbo, and 0-80% in 45 minutesB3. That is the AC50B's real inconvenience next to the RIVER 2, and unlike most inconveniences it's fixable with money.
“A 448Wh LiFePO4 battery with 700W output (1,000W Power Lifting), rated for 2,500+ cycles to 80% — years of reliable use.”
Sources
amazon.com · backuppowerhub.com · the-gadgeteer.com · t3.com · bluettipower.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
- The RIVER 2 is the older, cheaper unit on the same core platform — reasonable for budget indoor use but louder and less refined than the RIVER 3. [RIVER 2 · 2 entries]
- Affordable, genuinely portable LFP unit with 700W output, 2,500+ cycles, fast Turbo charging, and B80 expandability. [AC50B · 3 entries]
- A1
“The RIVER 2's spec data doesn't include a specific dB rating, and owner reports suggest it's noticeably louder under load than the newer RIVER 3.”
backuppowerhub.com — EcoFlow RIVER 2 vs RIVER 3 · 2026 · [negative]
- A2
“Shares the same core platform as the RIVER 3 — 300W output, LiFePO4 chemistry, and roughly 60-minute fast charging — and remains a popular, proven budget small-format unit.”
ecoflow.com / versus.com — RIVER 2 vs RIVER 3 · 2026 · [positive]
- A3
“For strictly indoor use where every dollar counts, the RIVER 2 is still a reasonable choice — but it lacks the RIVER 3's refinements like waterproofing, faster UPS, and quieter operation.”
backuppowerhub.com — RIVER 2 vs RIVER 3 recommendation · 2026 · [mixed]
- B1
“A 448Wh LiFePO4 battery with 700W output (1,000W Power Lifting), rated for 2,500+ cycles to 80% — years of reliable use.”
amazon.com / backuppowerhub.com — AC50B review · 2026 · [positive]
- B2
“At 14.8 lbs it's meaningfully lighter than the AC70 (21.4 lbs) — a genuinely portable sub-15-lb unit with a long-cycle battery and 700W output at an easy-to-justify price.”
backuppowerhub.com / the-gadgeteer.com — AC50B review · 2026 · [positive]
- B3
“Standard AC charging is about 3 hours, dropping to 1.25 hours with the optional 480W Turbo charger; 0-80% in 45 minutes.”
amazon.com / t3.com — AC50B review · 2026 · [positive]
Research compiled August 1, 2026.
Who Should Buy Which
Buy the RIVER 2 if you…
- →You carry it on foot. 7.8 lbs is a one-handed grab you can walk with; 14.8 lbs is a set-it-down-when-you-arrive weight, and that difference is the RIVER 2's honest advantage.
- →You recharge indoors against a clock. About an hour to full on a wall outlet against roughly three is a real daily convenience if you're topping up between short tripsA2B3.
- →You're running a laptop and phones indoors and every dollar counts. That is precisely the use the field write-ups still endorse it forA3.
Buy the AC50B if you…
- →You're powering a CPAP. 381Wh of usable capacity against a 320Wh night is the one thing on this page that should move $190, and the 45 dBA fan is the bonus.
- →You need to start something the RIVER 2 can't. 1,000W of peak against 600W is the gap between an appliance that runs and one that clicks and gives up.
- →You'll charge from a panel. 200W of solar input refills 448Wh in roughly the time 110W takes to refill 256Wh, so off-grid the bigger battery costs you nothing in daylight.
- →You want the purchase to age well. Same 3,000 cycles, but 1,344 kWh banked over the life instead of 768, at 21 cents a kilowatt-hour.
If neither fits
If your shopping list includes a weekend of camping (2,100Wh), a workday off-grid (910Wh), an eight-hour outage (1,645Wh) or van life (4,685Wh), close this tab and buy neither. Both of these are top-up boxes for phones, laptops, lights and a CPAP, and no amount of choosing between them changes the class. Shop for something that clears 1,645Wh on its own, buy it once, and skip the upgrade you'd otherwise be making in a year.
The Bottom Line
Take the AC50B. The $190 buys watt-hours at about 47 cents each, less than the rate you're already paying for the ones inside either box, and it buys the only outcome on this page that actually flips: a CPAP night the RIVER 2 gets roughly two-thirds of the way through.
The RIVER 2 is still right for two specific lives. You carry it somewhere a car can't go, or you recharge it against a clock at a wall outletA2. Neither describes most people. And if you do take the AC50B, buy it direct from BLUETTI. The box is the strong part of that company; the support desk is the part you want a clean receipt for.
Frequently Asked Questions
Answers drawn from the spec record and cited owner research.
Is the BLUETTI AC50B worth $190 more than the EcoFlow RIVER 2?
Yes, if you're buying watt-hours. The $190 gap buys the 192Wh between 256 and 448, which is about 47 cents per watt-hour, cheaper than the 74 and 62 cents per watt-hour you're paying for the capacity already inside either unit. Just don't spend it on the ports: USB-C is 65W against 60W and you will never feel that.
Can the EcoFlow RIVER 2 or the BLUETTI AC50B run a CPAP all night?
The AC50B can. The RIVER 2 can't. A full night's CPAP profile draws about 320Wh, and after inverter losses the RIVER 2 has roughly 218Wh to give (256Wh x 0.85) against the AC50B's 381Wh (448Wh x 0.85). The AC50B is also the quieter of the two at 45 dBA against 50, which matters more than capacity when the unit is sitting beside your pillow.
Will either one get me through an 8-hour power outage?
No. That profile wants 1,645Wh, which is more than four times what the AC50B can deliver and more than seven times the RIVER 2's usable pool. Both will keep phones, a router and some lights running, which is genuinely worth having. Neither is a refrigerator plan, and if that's what you're after you should shop a full size class up.
Which is quieter, the RIVER 2 or the AC50B?
The AC50B, at 45 dBA against the RIVER 2's 50. Reviewers also describe the RIVER 2 as noticeably louder under load than the newer RIVER 3, so the spec sheet and the write-ups agree here. There's a mechanical reason behind it: the same load is a smaller share of the AC50B's 700W inverter than of the RIVER 2's 300W, so its fan simply has less work to do.
Which one charges faster?
It depends where you're plugged in. On a wall outlet the RIVER 2 wins outright at about an hour to full, against roughly three hours for the AC50B on its standard charger or 1.25 hours with the optional 480W Turbo charger. On solar it's a wash: 256Wh over 110W of input and 448Wh over 200W both land near two and a half hours of rated sun.
Brand matchup
EcoFlow vs BLUETTI: measured across every matchup →Where to buy
EcoFlow RIVER 2
$209.00
$209.00 · direct from EcoFlow
Last checked 20 days ago. Prices move — check before you buy.
BLUETTI AC50BPick
$399.00
$399.00 · direct from BLUETTI
Last checked 1 day ago. Prices move — check before you buy.
Prices may vary by retailer and are subject to change.