Head-to-head test
EcoFlow DELTA 2 vs EcoFlow RIVER 2 Pro
The DELTA 2 has left EcoFlow's store, and its smaller sibling, the RIVER 2 Pro, is still on sale. Choosing it means trading down: a smaller battery, less than half the inverter, no expansion. In return you carry 9.8 lb less.
Full profiles: EcoFlow DELTA 2 β Β· EcoFlow RIVER 2 Pro β
Looking for a different matchup? EcoFlow DELTA 2 vs DELTA Pro Β· EcoFlow DELTA 2 vs RIVER 2
Written by Ian SchneiderUpdated
Solar & Off-Grid Tester, Station Arena Test Desk
Spec deltas
EcoFlow has stopped selling the DELTA 2. Its store page now forwards to the DELTA 3. The RIVER 2 Pro is still on sale, and it's the one people look at when they want the same brand in a smaller box.
It is smaller in every way that shows on a spec sheet. The battery holds 768Wh to 1,024Wh. The inverter, the part that turns battery power into wall power, is less than half the size, and so is the solar input. It's also sealed, so the battery you buy is the battery you keep.
What you get back is weight, 17.2 lb to the DELTA 2's 27. If I were carrying a battery down from the cabin to a lakeside picnic every weekend, I'd feel that on the walk back up.
What the Numbers Reveal
Each conclusion stated first β the numbers behind it on one line, the full analysis below.
continuous output
Surge is the short burst a motor needs to start, and the DELTA 2's higher ceiling starts things the RIVER 2 Pro can't. The RIVER 2 Pro keeps more headroom over its own rating, 2x to 1.5x, but only inside an 800W limit.
DELTA 2 continuous output is 1,800W against RIVER 2 Pro's 800WDELTA 2 surge ceiling is 2,700W against RIVER 2 Pro's 1,600W
Why it mattersCheck the watts of anything with a motor or a heating element against 800W before you buy the RIVER 2 Pro.
Seventeen watt-hours is about one small device's worth across the afternoon. The DELTA 2 covers the same afternoon with room left.
Tailgate Party needs 670WhRIVER 2 Pro has about 653Wh usable, 17Wh shortDELTA 2 covers it with 200Wh to spare
Why it mattersIf your loads sit around this size, the RIVER 2 Pro asks you to keep an eye on the battery.
The DELTA 2 narrows the shortfall, and an expansion battery could close it. The RIVER 2 Pro can't grow at all.
Weekend Camping needs 2,100Wh; both units fall shortVan Life Daily needs 4,685Wh; both units fall shortRIVER 2 Pro is fixed at 768Wh with no expansion
Why it mattersIf camping weekends or van life are the plan, size up from the start.
The specific dimensions that decide these two units β everything else is a tie.
Your Life, Your Pick
Selected because: The tailgate is the one load the DELTA 2 covers and the RIVER 2 Pro misses, by 17Wh. Smaller loads fit both, bigger ones fit neither.
Four of the six loads need more than either has to give: a camping weekend, an eight-hour blackout, a full remote workday and van life. The DELTA 2 gets closer each time, and it misses the workday by only a few percent.
The CPAP night fits both, the RIVER 2 Pro using about half its battery and the DELTA 2 about a third. The tailgate is the one row that splits them.
Lifetime Value
Selected because: The DELTA 2 has no price now, so this section counts energy: 3,072 kWh over its rated life against 2,304 kWh for the RIVER 2 Pro.
A cycle is one full drain and refill, and both are rated for 3,000 of them. Each kilowatt-hour from the RIVER 2 Pro works out to $0.15 at today's price. Cycled every weekend, either has decades of rated life in it.
What the Specs Don't Tell You
Selected because: Five cards fire: noise, expansion, surge, switchover and warranty.
The warranty card is a formality, five years on each. The surge card goes to the DELTA 2 on raw starting power. Switchover is the gap between the wall going dead and the battery taking over. The DELTA 2 is rated no worse than 20ms and the RIVER 2 Pro no worse than 30ms. Many desktops won't ride through 30ms, so the RIVER 2 Pro is a poor fit under a computer you can't afford to have reboot.
The noise card compares two ratings EcoFlow published differently, so leave it out of the decision. The expansion card stands. The RIVER 2 Pro is sealed.
Growth Path
Selected because: The RIVER 2 Pro is sealed at 768Wh; the DELTA 2 takes expansion batteries but is no longer sold.
solar input
The RIVER 2 Pro's growth path ends at checkout. The DELTA 2 takes EcoFlow expansion batteries, which matters if you already own one.
A new buyer can get a RIVER 2 Pro sized for today's loads, or look at the DELTA 3, which EcoFlow names as the DELTA 2's replacement.
Portability & Form Factor
Selected because: 9.8 lb separates them, the RIVER 2 Pro's clearest advantage.
weight
17.2 lb against 27 lb. The RIVER 2 Pro goes in one hand with a bag in the other. The DELTA 2 is a deliberate lift. If the battery travels more than it sits, you'll notice that more than any other spec.
Strengths & trade-offs
EcoFlow DELTA 2
Strengths
- +Larger battery capacity
- +Higher AC output
- +Faster solar charging
Trade-offs
- βNo major technical downsides compared to rival.
EcoFlow RIVER 2 Pro
Strengths
- +Lighter by 9.8 lb
Trade-offs
- βWeaker inverter (-1,000W) limits appliance compatibility.
- βCan receive complaints about fan noise under heavy load.
- βSealed capacity β the DELTA 2 can add batteries to grow past 768Wh; this one can't.
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 DELTA 2 comes up 1,230Wh short (about 41% covered), the RIVER 2 Pro 1,447Wh (31%). Treat this as partial cover β enough for the essentials in it, not the whole list.
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 DELTA 2 comes up 775Wh short (about 53% covered), the RIVER 2 Pro 992Wh (40%). Treat this as partial cover β enough for the essentials in it, not the whole list.
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
Both cover a CPAP night. The two noise ratings were published differently, so neither tells you which is quieter at a 40W bedside load.
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
This scenario needs 910Wh and neither unit quite finishes it. The DELTA 2 lands within 5% of it β close enough that trimming one appliance, or accepting a shorter evening, gets you there on the day.
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
DELTA 2
This is the one row that splits them. The DELTA 2 clears the 670Wh afternoon with 200Wh to spare. The RIVER 2 Pro comes up 17Wh short. Leave one small device off and it gets there.
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 DELTA 2 comes up 3,815Wh short (about 19% covered), the RIVER 2 Pro 4,032Wh (14%). 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: DELTA 2 runs 4.2h vs 3.2h.
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 0β58hComfort & Convenience
Makes off-grid life actually enjoyablescale 0β11.6hHigh-Draw Appliances
These reveal the real limitsscale 0β0.9hΒΉ 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 25, 2026
Verdict: the EcoFlow RIVER 2 Pro
EcoFlow no longer sells the DELTA 2, so the RIVER 2 Pro is the only one of the two you can buy new. For light jobs it's a sound buy. It covers a CPAP night with half its battery left, and it weighs 17.2 lb to the DELTA 2's 27. Confidence stops at 6 because it is the smaller machine in most other ways. Its inverter runs 800W to 1,800W, it can't take an expansion battery, and it misses our tailgate load by 17Wh. If you need what the DELTA 2 did, EcoFlow points you to the DELTA 3.
Editor-assigned confidence, based on cited owner research and spec analysis.
List prices as of October 25, 2026. The links below open EcoFlow's current price.
$389.00 Β· direct from EcoFlow
Last checked 28 days ago. Prices move β check before you buy.
Written by Ian Schneider, Solar & Off-Grid Tester Β· Station Arena Test Desk Β· Updated October 25, 2026
Black Friday Β· 26 days out
Price to beat:RIVER 2 Pro $349
We have never seen it discounted, so any real cut would be a first.
Measured Data
Benchmark scores and the full spec record, side by side.
Benchmark scores
Not rated for both units (minimum threshold unmet): UPS, RV Living, Home Backup, Food Truck.
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, DELTA 2 rates 4.1/5 (50th percentile of 27 Everyday-class units), and RIVER 2 Pro rates 4.7/5 (84th percentile of 20 Compact-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.
Two Ratings, Two Meanings
The RIVER 2 Pro's 62dB is a maximum, reached when charging and discharging at high wattage. The DELTA 2's 50dB was not published the same way.
Sealed at 768Wh
The RIVER 2 Pro can't take an expansion battery. The DELTA 2 can, but it's no longer sold.
Ratio and Ceiling Disagree
The RIVER 2 Pro keeps more headroom over its own rating, 2x to 1.5x. The DELTA 2 has the higher ceiling, 2,700W to 1,600W, and the ceiling decides whether a motor starts.
20ms vs 30ms
Rated no more than 20ms on the DELTA 2 and no more than 30ms on the RIVER 2 Pro. Many desktops won't ride through 30ms. Both are ratings, not lab results.
Five Years Each
Both carry EcoFlow's five-year warranty.
Full record above β the Test Desk pick is the RIVER 2 Pro.
Check RIVER 2 Pro 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 DELTA 2 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 RIVER 2 Pro works out at $0.15/kWh over its rated life. If you already own the DELTA 2, the hardware comparison still holds: over its rated life the DELTA 2 delivers about 3,072 kWh and the RIVER 2 Pro about 2,304 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.
Growth path
DELTA 2
EXPANDABLESupports EcoFlow expansion batteries, so you can add capacity later without replacing the base unit β useful if your needs may climb past 1,024Wh.
Accepts up to 500W of solar. Suitable for a 1-2 panel setup.
Generous port selection supports complex multi-device setups.
Expansion batteries are EcoFlow-specific. You're investing in the EcoFlow ecosystem.
RIVER 2 Pro
FIXED CAPACITYFixed at 768Wh, 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.
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 DELTA 2 is no longer sold (EcoFlow points owners to the DELTA 3). That leaves the RIVER 2 Pro: it is sealed at 768Wh, so buy the size that covers you now. The DELTA 2's expandability still matters if you already own one, but it isn't a reason to pick it over the RIVER 2 Pro.
What Owners Report
Patterns from published owner reports and long-term reviews β every claim cited to its source below.
EcoFlow DELTA 2
The fan is the recurring complaint. Reviewers say it comes on above roughly 120W and runs at about 48 to 55 dB near full loadA1. Fast charging has been compared to a gaming laptop, and the app lets you slow the charge to quiet itA2. EcoFlow has said it plans a firmware fixA4.
One reviewer put it through 18 months of outages, camping trips and home-office days and praised its fast charging, its LFP battery and its expansion pathA3. LFP is lithium iron phosphate, a chemistry chosen for long life.
βWhen charging at 1200W the fans sound like a gaming laptop, though you can lower the charging speed in the app to silence it.β
Sources
portablepowerlab.com
EcoFlow RIVER 2 Pro
Our research found little owner commentary specific to the RIVER 2 Pro, as opposed to the wider RIVER 2 lineB0. One owner describes a fan-noise fix that meant cutting away some internal plasticB1. That is a hobbyist's project, and I wouldn't recommend it.
One CPAP user living in a van described running a ResMed AirSense 11 overnight off a DC cable and a battery bank without troubleB4. Running a CPAP from DC skips the inverter, which usually saves battery.
βWill using River 2 Pro as a UPS affect battery life ...β
Sources
ctrl-alt-rees.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
- Fan noise under moderate-to-high load is the dominant, repeatedly-cited complaint; the fan spins up above ~120W. [DELTA 2 Β· 3 entries]
- Fan noise at high wattage charging/discharging is a consistent owner and manufacturer-acknowledged complaint, severe enough that some owners physically mod the unit with quieter fans. [RIVER 2 Pro Β· 2 entries]
- A1
βFans trigger at anything above 120 watts; at maximum load (1,500β1,800W) they run continuously at ~48β55 dB. Powering medical equipment above 120W in a bedroom means listening to the fans or running an extension cable out of the room.β
portablepowerlab.com β EcoFlow Delta 2 Review: 6 Months of Real Use; PCWorld β EcoFlow Delta 2 review Β· 2026 Β· [negative]
- A2
βWhen charging at 1200W the fans sound like a gaming laptop, though you can lower the charging speed in the app to silence it.β
PCWorld β EcoFlow Delta 2 power station review Β· 2026 Β· [mixed]
- A3
βAfter 18 months of real-world testing through multiple power outages, camping trips, and daily home-office use, the unit earned recognition for fast charging, reliable LiFePO4 battery chemistry, and expandability.β
portablepowerlab.com β EcoFlow Delta 2 Review: 6 Months of Real Use Β· 2026 Β· [positive]
- A4
βEcoFlow officials indicated they plan to address the fan noise in an upcoming firmware update, as they have for other models after release.β
portablepowerlab.com β EcoFlow Delta 2 Review Β· 2026 (dated claim β may be partially addressed) Β· [mixed]
- B1
βI've since performed the same mod on my RIVER 2 PRO and it works great for that unit, too - although it did involve cutting away some of the internal plastic.β
ctrl-alt-rees.com blog β 'EcoFlow RIVER 2 Noisy Fan Fix!' Β· 2022-11-17 Β· [negative]
- B2
βWhen charging and discharging at high wattage, RIVER 2 Max and RIVER 2 Pro may make a noise up to 62db.β
EcoFlow official product page β RIVER 2 Series specs/FAQ footnotes Β· unknown Β· [negative]
- B4
βI'm very new to CPAP (1 week) and I live in a van. I have solar and a decent battery bank and I've got the ResMed DC-DC cable which powers my AirSense 11 AutoSet overnight no problem.β
Apnea Board forum β '[Equipment] EcoFlow River 2 Pro' thread Β· 2025-07 Β· [mixed]
Research compiled October 25, 2026.
What Owners Actually Report
Drawn from 176 comments on independent review channels β not from retailer reviews, which skew to the first week of ownership. Each line is our summary of one commenter's claim, linked to the original. We record what they said, including where it contradicts the spec sheet.
EcoFlow DELTA 2
224 claims from 155 comments Β· 178 from owners Β· 60 with figures
- Runtime
- 32 Β· 13% negative
- Price & value
- 38 Β· 4% negative
- Charging
- 17 Β· 23% negative
- Durability
- 22 Β· 67% negative
- Warranty & support
- 22 Β· 59% negative
What owners complain about
Ignores solar unless he unplugs it from the wall, so he switched to the AC180.
Solar inputowner63 agreedsource β
His Delta 2 went bad three months after purchase and EcoFlow agreed it was defective.
Durabilityownerafter 3 months236 agreedsource β
Past 30 days the five-year warranty only gets a refurbished unit covered for 30 days.
Warranty & supportowner236 agreedsource β
What owners praise
DELTA 2 plus extra battery and 600W solar cost ~$1200 and paid for itself in under 2 years in California.
Price & valuemeasuredowner736 agreedsource β
Batteries still hold 98%+ capacity, ahead of the 80%-at-10-years warranty curve.
Durabilitymeasuredowner736 agreedsource β
Gets 180-190W into it from a 100Ah LiFePO4 via XT60i cable, no converter needed.
Chargingmeasuredowner106 agreedsource β
EcoFlow RIVER 2 Pro
32 claims from 21 comments Β· 27 from owners Β· 8 with figures
- Runtime
- 5 Β· 0% negative
- Size & weight
- 2 Β· 0% negative
- Solar input
- 2 Β· 0% negative
- Inverter & surge
- 3 Β· 23% negative
- App & firmware
- 3 Β· 0% negative
What owners complain about
Wildly fluctuating DC output on two separate units bought from different retailers.
Build qualityowner1 agreedsource β
Does tend to self-discharge, so he keeps it on the low 100W power setting.
Idle drainowner3 agreedsource β
Unit would not power on within a week of purchase despite a full charge.
Durabilityownersource β
What owners praise
Ran a portable fridge/freezer in a car for 5 hours in 110F Tucson heat, still at 78%.
Runtimemeasuredowner40 agreedsource β
At 17 lbs it is his top pick for grab-and-go power.
Size & weightmeasuredowner4 agreedsource β
Recharges back to 100% in less than an hour.
Chargingmeasuredowner4 agreedsource β
Claims are weighted by how specific they are, whether the commenter owns the unit, and how many readers agreed. Comments that mention a product under a rival's review count for more, because the commenter had no reason to be there. This is what buyers report, not our test results β for measurements we ran ourselves, see the methodology.
Who Should Buy Which
Buy the DELTA 2 if youβ¦
- βYou already own a DELTA 2. It beats the RIVER 2 Pro on output, surge and expansion.
- βYou run something with a motor. The DELTA 2's higher surge ceiling starts more.
Buy the RIVER 2 Pro if youβ¦
- βYou're buying new and your loads stay small: a CPAP, a phone, a laptop, a few lights.
- βYou carry it often, and 17.2 lb is a lift you won't think twice about.
- βYou don't need to plug in anything over 800W, and you're fine with a battery that can't grow.
If neither fits
If the real job is a camping weekend at 2,100Wh, an eight-hour blackout at 1,645Wh or van life at 4,685Wh, neither covers it. Look at a larger, ideally expandable station instead.
The Bottom Line
Buy the RIVER 2 Pro if you're buying new and your loads stay small. It covers a CPAP night with room left and weighs 9.8 lb less.
Keep the DELTA 2 if you own one. It runs bigger things and takes an expansion battery. If you need that and you're buying new, EcoFlow points you to the DELTA 3.
Frequently Asked Questions
Answers drawn from the spec record and cited owner research.
Is the EcoFlow DELTA 2 still sold?
No. EcoFlow no longer sells the DELTA 2, and its store page forwards to the DELTA 3. The RIVER 2 Pro is still on sale, so it is the one of these two you can buy new.
Is the RIVER 2 Pro a replacement for the DELTA 2?
Not a like-for-like one. The RIVER 2 Pro holds 768Wh to the DELTA 2's 1,024Wh, runs 800W continuous to 1,800W, and can't take an expansion battery. It is 9.8 lb lighter. EcoFlow names the DELTA 3 as the DELTA 2's replacement.
Which one can run a space heater or window AC?
The DELTA 2 has the bigger inverter, 1,800W continuous with a 2,700W surge ceiling, against the RIVER 2 Pro's 800W and 1,600W. Check your appliance's rated watts against those figures. Battery size still limits how long either runs a big load.
Is the DELTA 2 quieter than the RIVER 2 Pro?
The published figures can't answer that. EcoFlow rates the DELTA 2 at 50dB and says the RIVER 2 Pro may reach 62dB when charging and discharging at high wattage. The two figures were not published the same way, so they are not a like-for-like comparison.
Can either of these expand its capacity later?
Only the DELTA 2. It supports EcoFlow expansion batteries. The RIVER 2 Pro is fixed at 768Wh for the life of the unit.
Where to buy
EcoFlow DELTA 2
No longer sold
EcoFlow RIVER 2 ProPick
$389.00
$389.00 Β· direct from EcoFlow
Last checked 28 days ago. Prices move β check before you buy.
Prices may vary by retailer and are subject to change.