Head-to-head test
EcoFlow RIVER 2 Max vs BLUETTI AC50B
EcoFlow no longer sells the RIVER 2 Max, so the live choice is the AC50B: 200W more continuous output from a smaller battery, built for loads that are big and brief rather than long.
Full profiles: EcoFlow RIVER 2 Max β Β· BLUETTI AC50B β
Written by Wenny ZhengUpdated
Portable Power Tester, Station Arena Test Desk
Spec deltas
EcoFlow no longer sells the RIVER 2 Max. Its store lists the 512Wh unit sold out in every version, and the model it sells in its place is the RIVER 2 Max 500. That leaves one live candidate on this page, and it's a good one for the right buyer: take the BLUETTI AC50B.
The comparison still earns its keep, because plenty of people own a RIVER 2 Max or are looking at a leftover listing for one. On specs the two split cleanly. The RIVER holds more, 512Wh to 448, publishes a 1,000W surge, and weighs 13.4 lbs to the AC50B's 14.8. The AC50B runs 700W continuous to the RIVER's 500W and carries the tighter UPS ceiling, β€20ms against β€30ms.
That output is the AC50B's whole case, and it comes with a catch worth saying first: 700W from a 448Wh battery is a short session. Flat out, the 381Wh it can deliver after the 85% derate we apply lasts about half an hour. It's the unit for a load that's big and brief, a kettle in Power Lifting mode or a desktop riding out a flicker, not one you leave running all evening. EcoFlow describes the RIVER 2 Max 500 as the same machine with a slightly smaller battery, so if the EcoFlow's mix is what you wanted, that's the version to weigh against this one.
What the Numbers Reveal
Each conclusion stated first β the numbers behind it on one line, the full analysis below.
continuous output
So the extra 200W is headroom, not endurance. It decides whether a load between 500W and 700W runs at all, and once it does, the clock moves fast. That's the right shape for a short, hard job and the wrong one for anything you'd leave on through the evening.
BLUETTI AC50B: 700W continuous output, 448Wh capacityEcoFlow RIVER 2 Max: 500W continuous output, 512Wh capacityUsable after the flat 85% derate: AC50B 381Wh, RIVER 2 Max 435Wh
Why it mattersBuy the AC50B when one steady load between 500W and 700W is the reason you're shopping; if your loads are small and long, the extra output buys you nothing.
But the battery behind that fast transfer covers 42% of a full workday's load. As a desk UPS it's a bridge: long enough to save the file and shut down cleanly, or to keep a router up through a short outage, not long enough to keep working through a long one.
AC50B UPS switchover rated β€20ms; RIVER 2 Max rated β€30ms (both ceilings, not measurements)Remote Workday scenario needs 910WhAC50B covers 42% of it, coming up 529Wh short
Why it mattersHome-office buyers who want a ride-through for a router or a desktop should take the AC50B and test their own machine on it; anyone who needs to work through an outage needs a much larger battery.
So recharging is a daily chore, not an occasional one. From empty, 448Wh over 200W of solar is a little over two hours of full-rated sun (448 Γ· 200), which a clear midday delivers and an overcast one may not; at an outlet, reviewers put the standard charge at about 3 hoursB3.
CPAP Overnight needs 320Wh; the AC50B delivers 381Wh usable, leaving 61WhAC50B solar input: 200WAC50B standard AC charge about 3 hours, 1.25 hours with the optional 480W Turbo chargerB3
Why it mattersCPAP users heading off-grid for more than one night should budget a 200W panel and a sunny midday into the plan, or treat the AC50B as a one-night battery.
Capacity
That's only a good trade if a specific load between 500W and 700W is failing on the RIVER today. Otherwise the switch spends battery, surge headroom and refill speed to buy output you aren't using.
RIVER 2 Max: 1,000W published surge; AC50B: no published surge figure above its 700W ratingRIVER 2 Max: full charge in about 60 minutes via X-StreamA2RIVER 2 Max 512Wh vs AC50B 448Wh
Why it mattersRIVER 2 Max owners should keep theirs, and add an AC50B only if a particular appliance is tripping the 500W ceiling.
The specific dimensions that decide these two units β everything else is a tie.
What the Specs Don't Tell You
Selected because: The UPS ceilings, Power Lifting and the warranty's conditions are where the live unit's real differences sit.
Four cards fire, and the one that changes a purchase is the UPS rating. β€20ms on the AC50B and β€30ms on the RIVER 2 Max are both ceilings, not bench results, but they land on opposite sides of where desktop power supplies start dropping out. For a router, either is fine. For a tower with unsaved work, only one is in the conversation.
Power Lifting is real but narrow, and the card spells out why. The warranty card is a tie on paper with a string attached on the AC50B's side: its five years depends on buying direct or registering. The noise card is the one not to over-read. BLUETTI and EcoFlow publish on opposite conventions, a best case against a maximum under heavy load, so the two ratings don't describe the same moment and no gap between them is something you can plan around.
Runtime: Will It Power Your Gear?
Selected because: The AC50B runs heavier loads from the smaller battery, so how long each load lasts is the trade to understand.
continuous output
The RIVER 2 Max carries 54 more usable watt-hours, 435 against 381 after the derate, and on a light load that's the difference between finishing the evening and not. It's the runtime column the RIVER wins, and it left the shelf with the RIVER.
The AC50B's runtime story is about load size, not length. Anything drawing between 500W and 700W gets a runtime on its side of the table and a fault on the RIVER's. Short runtimes, but runtimes, and if that load is the reason you're here, it's the only column that matters.
Your Life, Your Pick
Selected because: Only the CPAP night fits inside either battery, and it is a one-night-per-charge fit.
Five of the six rows read 'neither', and they mean it. An 8-hour blackout needs 1,645Wh and the AC50B covers 23% of it; a camping weekend and a van-life day are further out still. These are small stations, and no tiebreak changes that.
The CPAP row is the one that matters, and the AC50B takes it on availability rather than capacity: the RIVER 2 Max would finish the night with more left over. Either way it's one night per charge, so the panel or the wall outlet belongs in a CPAP plan as a requirement, not an accessory.
Brand Trust
Selected because: With one of these units out of production, what each maker does after the sale matters more than usual.
Brand matters here in an unusual way. EcoFlow offers no parts or service once a unit is out of warranty, and the RIVER 2 Max is no longer sold, so for an owner the warranty term is the whole support story. Keep the proof of purchase somewhere you can find it.
BLUETTI's risk is the support desk: heavily email-based, with China-timezone delays and outcomes that swing from smooth to weeks of back-and-forth. Buying direct from BLUETTI tends to go better, and it's also the route that secures the AC50B's full five-year term. One move, two problems handled.
Strengths & trade-offs
EcoFlow RIVER 2 Max
Strengths
- +Lighter by 1.4 lb
- +Larger battery capacity
- +Faster solar charging
Trade-offs
- βCan receive complaints about fan noise under heavy load.
BLUETTI AC50B
Strengths
- +Higher AC output
Trade-offs
- βNo 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 six real-world scenarios. Here's which unit survives your actual life.
SCN-01 Β· 2 nights Β· 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 Max comes up 1,665Wh short (about 21% 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
LOADΒ Β Phone Charger 15WΓ6h Β· LED Lights 40WΓ8h Β· Box Fan 75WΓ14h Β· CPAP Machine 40WΓ16h
SCN-02 Β· 8 hours Β· 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 2 Max comes up 1,210Wh short (about 26% covered), the AC50B 1,264Wh (23%). 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
LOADΒ Β Fridge 150WΓ8h Β· Router + Modem 20WΓ8h Β· LED Lights (4 bulbs) 40WΓ6h Β· Phone Charger 15WΓ3h
SCN-03 Β· 8 hours Β· needs 320Wh
CPAP Overnight
Sleep therapy without interruption β the #1 medical use case
Either unit
The AC50B gets the nod here, and not on capacity: it's the one you can buy, and it does cover the night. A 40W machine for eight hours is 320Wh against 381Wh usable after the 85% derate, leaving 61Wh. That's one night per charge, so recharge it every day. The RIVER 2 Max would finish with 115Wh left, which only matters if you already own one. Neither maker's noise rating describes a 40W draw: BLUETTI publishes a best case and EcoFlow a maximum under heavy load, so don't treat them as a difference you'll hear.
Battery budget usedlower = more headroom
LOADΒ Β CPAP Machine 40WΓ8h
SCN-04 Β· 8 hours Β· needs 910Wh
Remote Workday
Full work day off-grid without power anxiety
Neither unit
Neither covers a 910Wh workday: the AC50B gets through 42% of it and the RIVER 2 Max 48%. Where the AC50B earns a place at a desk is the switchover, rated β€20ms to the RIVER's β€30ms, which makes it a bridge for saving work and shutting down cleanly, not a way to work through the outage.
Battery budget usedlower = more headroom
LOADΒ Β Laptop 60WΓ8h Β· External Monitor 30WΓ8h Β· Router + Modem 20WΓ8h Β· Phone Charger 15WΓ2h
SCN-05 Β· 4 hours Β· needs 670Wh
Tailgate Party
Game day power for the crew
Neither unit
Neither carries a 670Wh tailgate alone, though both start the 400W peak. The AC50B gets 57% of the way and the RIVER 2 Max 65%, so this is a plan-around row: a shorter party or a second battery, not a reason to rule either out.
Battery budget usedlower = more headroom
LOADΒ Β Blender 400WΓ0.5h Β· LED TV (55") 80WΓ4h Β· Bluetooth Speaker 15WΓ4h Β· Phone Charger (Γ3) 45WΓ2h
SCN-06 Β· 24 hours Β· needs 4,685Wh
Van Life Daily
A full day of mobile living β the ultimate endurance test
Neither unit
Neither unit covers this scenario's 4,685Wh: the RIVER 2 Max comes up 4,250Wh short (about 9% 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
LOADΒ Β Mini-Fridge 150WΓ24h Β· Laptop 60WΓ4h Β· Phone Charger 15WΓ3h Β· LED Lights 40WΓ5h Β· Fan 75WΓ8h
The Load Test
RUNTIME = (Wh Γ 0.85) Γ· 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: RIVER 2 Max runs 2.1h vs 1.9h.
Planning for more than this? Describe your whole setup and get it sizedΒ β
Modeled from the spec record β same math as the tables below. Methodology
Runtime by appliance
Real-world runtime estimates for common appliances, modeled at 85% inverter efficiency.ΒΉ
Essentials
The basics you need runningscale 0β29hComfort & Convenience
Makes off-grid life actually enjoyablescale 0β5.8hHigh-Draw Appliances
These reveal the real limitsΒΉ Runtime = (capacity Γ 0.85) Γ· 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 β see methodology.
Conclusion
October 11, 2026
Verdict: the BLUETTI AC50B
Take the AC50B. EcoFlow no longer sells the RIVER 2 Max, so it can't be the recommendation, but the AC50B also earns the pick on its own terms for a specific buyer: 700W continuous against 500W, Power Lifting for resistive appliances rated up to 1,000W, and a UPS switchover rated β€20ms against β€30ms. The honest catch is that it does all this from the smaller battery, 448Wh to 512Wh, with no published surge figure, and reviewers put its standard wall charge at about 3 hours unless you add the optional Turbo chargerB3. If you already own a RIVER 2 Max and nothing you run needs more than 500W, keep it. If you liked the EcoFlow's mix and want it new, EcoFlow's replacement is the RIVER 2 Max 500; weigh that against the AC50B before you buy.
Editor-assigned confidence, based on cited owner research and spec analysis.
List prices as of October 11, 2026. The links below open BLUETTI's current price.
$399.00 Β· direct from BLUETTI
Last checked 28 days ago. Prices move β check before you buy.
Written by Wenny Zheng, Portable Power Tester Β· Station Arena Test Desk Β· Updated October 11, 2026
Black Friday Β· 26 days out
Price to beat:AC50B $279
The lowest we have recorded. A Black Friday price above it is a sale this unit has already had.
Measured Data
Benchmark scores and the full spec record, side by side.
Benchmark scores
Not rated for both units (minimum threshold unmet): UPS.
Full specifications
α΅ Derived: price Γ· rated capacity. See the data behind our comparisons β
Comparison ToolAdd more power stations, side by sideOpen Tool βHow these numbers are produced
Numeric verification
Every figure on this page traces to our spec database or arithmetic on it β no estimated numbers.
Owner claims
Statements about owner experience are cited to published reviews β see Sources & Research Notes below.
Runtime model
Runtime = (rated capacity Γ 0.85 inverter efficiency) Γ· 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 βClass ranking (the star rating)
Each unit's star score is a category ranking, not customer reviews β 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 5β . Here, RIVER 2 Max rates 3.7/5 (26th percentile of 20 Compact-class units), and AC50B rates 4.6/5 (79th percentile of 25 Personal-class units).
How the class ranking is computed βTest Notes & Caveats
Hidden gotchas and advantages we spotted that you won't find on the product page.
Fan Noise: Two Published Ratings
The AC50B is rated 45dB (like a running refrigerator), the RIVER 2 Max 62dB (like a normal conversation). Neither is a measurement on a shared bench β and the two are not even the same kind of figure: the RIVER 2 Max's is a MAXIMUM under heavy charge and discharge, while the AC50B's is its maker's best case, so the real gap can only be narrower than the numbers suggest, and may even run the other way. Take the pair as a prompt to find hands-on reports rather than as a gap you can act on. For most people, fan noise around 45dB and up is where sleep starts to suffer, and neither figure tells you what either unit does at a 40W draw.
Power Lifting: A Kettle Feature
BLUETTI's Power Lifting lets the AC50B run a resistive appliance rated up to 1,000W from its 700W inverter by feeding it less than it asks for, so a kettle still boils, just more slowly. It's scoped to resistive loads, so it does nothing for a fridge compressor, a pump or a power tool, and with no published surge figure on this record it isn't starting power either. On a 448Wh battery, a load that size is a short session regardless. Useful for the morning kettle; not a reason to plan an evening around a heater.
Switchover: The Tighter Ceiling Is BLUETTI's
Both ratings are ceilings, not bench results. The AC50B's β€20ms is fine on paper for routers and most electronics, with the fussiest desktop power supplies sitting right at that line. The RIVER 2 Max's β€30ms is a gap many desktops won't ride through, so an owner protecting a computer should plan on reboots. If unsaved work is what you're guarding, try the AC50B with your own machine before you trust it.
Warranty: Same Term, Different Fine Print
Both records carry five years. The AC50B's is BLUETTI's maximum: it applies when you buy direct from BLUETTI or register the unit, while reseller purchases carry a shorter term, so buy it where the full five years applies. For the RIVER 2 Max, the term matters to people who already own one, and it's the whole safety net: EcoFlow offers no parts or service once a unit is out of warranty.
Full record above β the Test Desk pick is the AC50B.
Check AC50B price βOwnership Analysis
What happens after you buy β 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
β warranty ends Β· Reaching the cycle rating means ~80% capacity remains β degraded, not dead.
Analyst note
The RIVER 2 Max is no longer sold, so there is no price to work its cost per kWh from, and this comparison doesn't quote one. On what you can actually buy today, the AC50B works out at $0.30/kWh over its rated life. If you already own the RIVER 2 Max, the hardware comparison still holds: over its rated life the RIVER 2 Max delivers about 1,536 kWh and the AC50B about 1,344 kWh. 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 β the wear horizon is identical and decides nothing here.
Brand trust
EcoFlow
Ecosystem
Largest in portable power β 12-15 models across DELTA Pro, DELTA 3, and RIVER 3 series, plus solar panels and smart home panels
Support
US-based phone/email/chat support (1-800-368-8604). Experiences are polarized β many report hassle-free prepaid-label replacements, but others report long waits and refurbished units sent for new claims. Pro tip: buying from Costco or Amazon gives you a stronger return safety net.
Community
Largest community in the space β Reddit r/Ecoflow_community (~31K members), multiple Facebook groups, and an official community forum
App experience
Rated 4.6/5 iOS (~8,400 ratings) Β· 4.2/5 Android (~17,000 ratings)
Unique strength
Fastest-charging technology (X-Stream), deepest product ecosystem, and most active innovation cadence. At the top of the range sit two whole-home paths: the TITAN line, one 5 kWh unit that grows to 30 kWh, and the DELTA Pro Ultra platform, which stacks batteries and inverters further β flagship paths, not line-wide features.
Worth knowing
EcoFlow offers no parts or service once a unit is out of warranty. With the RIVER 2 Max no longer sold, an owner's warranty term is the whole safety net, so keep the proof of purchase.
BLUETTI
Ecosystem
One of the broadest lineups β 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
The most inconsistent support of the major brands: heavily email-based, with China-timezone delays and outcomes that range from smooth to weeks of back-and-forth. Buying direct from BLUETTI tends to go better, and it's also how the AC50B gets its full warranty term.
Community
Active and growing β Reddit r/bluetti has a dedicated community. Second-largest after EcoFlow in engagement.
App experience
Rated 4.5/5 iOS and Android β tied for best app experience in the category. V3.0 UI redesign was well-received.
Unique strength
Among the best capacity-to-price ratios available β several Elite and Apex units are the lowest $/Wh in the catalog. Widest product diversity including industry-firsts like sodium-ion cold-weather units and dual solar+alternator vehicle hubs. LFP across the rest of the range, though rated cycle life spans 2,500 (EB3A) to 6,000, and it varies WITHIN the Elite range rather than tracking it β the Elite 300 and Elite 200 V2 are rated 6,000 while the Elite 30 V2, Elite 10 Mini, Elite 320 and Elite 400 are rated 3,000+ and the Elite 100 V2 4,000+, so check the specific model. Dual-voltage (120V/240V) in flagships.
Worth knowing
Customer support inconsistency is the #1 risk factor. Older/discontinued units may become unrepairable β no spare parts policy for some models. Some reports of erratic communication from support agents.
Analyst note
EcoFlow has the bigger ecosystem and community, but that's beside the point for a unit it no longer sells. BLUETTI's support is the risk to manage on the AC50B, and the fix is the same move that secures its full warranty: buy direct.
Growth path
RIVER 2 Max
FIXED CAPACITYFixed at 512Wh, with no expansion β so size it for your needs up front rather than planning to add capacity later.
Accepts up to 220W of solar. Limited to a single portable panel.
Adequate ports for most setups, but heavy users may want a power strip.
AC50B
FIXED CAPACITYFixed at 448Wh, with no expansion β 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 β see methodology
Analyst note
Growth only counts if you can still buy in, and the RIVER 2 Max is no longer sold (EcoFlow points owners to the RIVER 2 Max 500). That leaves the AC50B: it is sealed at 448Wh, so buy the size that covers you now. The RIVER 2 Max's fixed 512Wh still matters if you already own one, but it isn't a reason to pick it over the AC50B.
What Owners Report
Patterns from published owner reports and long-term reviews β every claim cited to its source below.
EcoFlow RIVER 2 Max
Reviewers keep coming back to two things: the RIVER 2 Max is light for 512Wh, lighter than some Li-Ion rivalsA1, and it fills from empty in about an hour on X-Stream chargingA2. The app gets steady praise for simple Wi-Fi and Bluetooth control, down to setting charge speed from a phoneA3.
One field test ran a telescope, a 65-inch TV, two laptops and phones through a 4-hour event with power to spareA4. This coverage comes from review sites and owner reviewsA0; none of it addresses support for the model now that EcoFlow has stopped selling it.
β512Wh in a light package of about 13 lbs, lighter than some of its closest competitors that use Li-Ion chemistry.β
Sources
storagereview.com Β· backuppowerhub.com Β· gagadget.com Β· ecoflow.com Β· thecampingnerd.com Β· thetechnologyman.com Β· bestbuy.com
BLUETTI AC50B
Coverage of the AC50B centers on how portable it is for 700W: at 14.8 lbs, reviewers call it meaningfully lighter than BLUETTI's own AC70B2. Charging is the other recurring note, about 3 hours on the standard AC charger and 1.25 hours with the optional 480W Turbo chargerB3, so the fast refill is an add-on purchase rather than the default.
Read the expansion claim carefully. BLUETTI's own FAQ describes the B80 battery working in Power Bank Mode, recharging the AC50B rather than extending it, and that's the manufacturer's description, not field evidenceB4. None of the coverage we have addresses the fan at a bedsideB1B2B3, so any noise figure for this unit is BLUETTI's own.
βA 448Wh LiFePO4 battery with 700W output (1,000W Power Lifting), rated for 2,500+ cycles to 80% β years of reliable use.β
Sources
amazon.com Β· backuppowerhub.com Β· the-gadgeteer.com Β· t3.com Β· 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
- Light weight, fast roughly-one-hour charging, and a simple capable app are the standout praise for this 512Wh unit. [RIVER 2 Max Β· 3 entries]
- Affordable, genuinely portable LFP unit with 700W output, 3,000+ rated cycles (BLUETTI), fast Turbo charging, and B80 support in Power Bank Mode (recharge, not expansion). [AC50B Β· 3 entries]
- A1
β512Wh in a light package of about 13 lbs, lighter than some of its closest competitors that use Li-Ion chemistry.β
storagereview.com / backuppowerhub.com β RIVER 2 Max review Β· 2026 Β· [positive]
- A2
βFully charges in about 60 minutes via X-Stream charging β far faster than most portable power stations β with multiple charging options.β
gagadget.com / ecoflow.com β RIVER 2 Max review Β· 2026 Β· [positive]
- A3
βThe EcoFlow app offers simple remote control and monitoring over WiFi and Bluetooth β view charge levels, customize settings, and adjust charging speed from a phone.β
thecampingnerd.com / ecoflow.com β RIVER 2 Max review Β· 2026 Β· [positive]
- A4
βUpgraded LFP chemistry rated for about 3,000 cycles, roughly a decade of everyday use; in field testing it powered a telescope, a 65-inch LED TV, two laptops, and phones through a 4-hour event with power to spare.β
thetechnologyman.com / bestbuy.com owner reviews β RIVER 2 Max Β· 2026 Β· [positive]
- B1
βA 448Wh LiFePO4 battery with 700W output (1,000W Power Lifting), rated for 2,500+ cycles to 80% β years of reliable use.β
amazon.com / backuppowerhub.com β AC50B review Β· 2026 Β· [positive]
- B2
βAt 14.8 lbs it's meaningfully lighter than the AC70 (21.4 lbs) β a genuinely portable sub-15-lb unit with a long-cycle battery and 700W output at an easy-to-justify price.β
backuppowerhub.com / the-gadgeteer.com β AC50B review Β· 2026 Β· [positive]
- B3
βStandard AC charging is about 3 hours, dropping to 1.25 hours with the optional 480W Turbo charger; 0-80% in 45 minutes.β
amazon.com / t3.com β AC50B review Β· 2026 Β· [positive]
- B4
βThe B80 can add 806Wh, but BLUETTI scopes this to "capacity expansion with B80 battery in Power Bank Mode" over an Aviation-to-XT60 cable β the pack recharges the unit rather than extending it as one system, so this is not expandability in the sense this site uses. At $279 it is BLUETTI's most affordable LiFePO4 station.β
bluettipower.com AC50B FAQ (primary) Β· 2026 Β· [positive]
Research compiled October 11, 2026.
Who Should Buy Which
Buy the RIVER 2 Max if youβ¦
- βYou already own a RIVER 2 Max and everything you run stays under 500W: keep it. It holds 64Wh more than the AC50B, publishes a 1,000W surge, and reviewers clock its full charge at about an hourA2, so switching would trade away more than it gains.
- βYou've spotted one in leftover retailer stock: the specs on this page still hold, but EcoFlow no longer sells it and now points buyers to the RIVER 2 Max 500, which is the live EcoFlow to weigh against the AC50B.
Buy the AC50B if youβ¦
- βYou need one load between 500W and 700W to run at all, a load the RIVER's 500W rating would refuse, and you're fine with that being a short session.
- βYou want a ride-through for a router or a desk setup: the β€20ms switchover ceiling is the tighter of the two, though the fussiest desktop power supplies sit right at that line, so test yours.
- βYour campsite morning starts with a kettle: Power Lifting runs resistive appliances rated up to 1,000W from the 700W inverter, just more slowly.
If neither fits
If the job is an 8-hour blackout, a camping weekend or daily van life, close this tab cheerfully: those loads run from 1,645Wh to 4,685Wh, and neither battery covers even a third of the smallest. Look at stations sized in kilowatt-hours rather than hundreds of watt-hours.
The Bottom Line
Take the AC50B. The RIVER 2 Max is gone from EcoFlow's store, and the AC50B is the right fit for anyone whose reason to shop is a single load between 500W and 700W, or a computer that wants the tighter β€20ms switchover. Know the shape of what you're buying: big loads, short sessions, and a battery smaller than the EcoFlow's.
Own a RIVER 2 Max already? Keep it unless something you run is tripping that 500W ceiling. Want the EcoFlow formula new? Weigh the RIVER 2 Max 500 against the AC50B. Everyone else with a big, brief load: go get the AC50B.
Frequently Asked Questions
Answers drawn from the spec record and cited owner research.
Is the EcoFlow RIVER 2 Max discontinued?
As far as buying new goes, yes: EcoFlow's store lists it sold out in every version and sells the RIVER 2 Max 500 in its place. The specs on this page are still accurate for anyone who owns one. Of these two, the AC50B is the one you can buy new.
Can the BLUETTI AC50B run a 1,000W kettle?
Yes, in Power Lifting mode. It runs resistive appliances rated up to 1,000W from its 700W inverter by delivering less power than they ask for, so the kettle boils more slowly. It does nothing for a fridge compressor, a pump or a power tool, and BLUETTI publishes no surge figure for the AC50B, so don't read the mode as starting power.
Will the AC50B run a CPAP all night?
Yes, for one night. A 40W machine over eight hours needs 320Wh, and the AC50B delivers about 381Wh after the 85% derate we apply, leaving 61Wh. Plan to recharge every day, and check your machine's actual draw, since a hungrier one eats that margin fast.
Is the AC50B a good UPS for a desktop computer?
It's the better-rated of these two, with a switchover ceiling of β€20ms against the RIVER 2 Max's β€30ms, but the fussiest desktop power supplies sit right at 20ms, so test it with your machine. It's also a bridge rather than a backup: it covers 42% of a 910Wh workday, enough to save work and shut down, not to keep working.
Does the BLUETTI AC50B expand with the B80 battery?
Not in the sense of becoming one bigger station. BLUETTI's own FAQ scopes the B80 to Power Bank Mode, where it recharges the AC50B rather than extending it. Treat the AC50B as sealed at 448Wh and buy it for what you need now.
Where to buy
EcoFlow RIVER 2 Max
Sold out at EcoFlow
BLUETTI AC50BPick
$399.00
$399.00 Β· direct from BLUETTI
Last checked 28 days ago. Prices move β check before you buy.
Prices may vary by retailer and are subject to change.