Head-to-head test
EcoFlow DELTA 3 Plus vs BLUETTI AC180
The AC180 is $200 cheaper with a bigger tank for daily use; the DELTA 3 Plus is the one built for the day the power actually goes out — a faster switchover, more surge headroom, and a real expansion path.
Written by Ian SchneiderUpdated
Solar & Off-Grid Tester, Station Arena Test Desk
EcoFlow
DELTA 3 Plus
3,225Power Score · Appliance Class
$689.00 list · direct from EcoFlow
BLUETTI
AC180
3,200Power Score · Appliance Class
$499.00 list · direct from BLUETTI
Spec deltas
The BLUETTI AC180 costs $200 less than the EcoFlow DELTA 3 Plus and holds 128Wh more capacity — 1,152Wh against 1,024Wh. On price and capacity alone, it's the easy pick.
The DELTA 3 Plus answers back everywhere else: a 10ms UPS switchover against the AC180's 20ms, 900W more surge headroom, double the solar input, and a genuine expansion path the AC180 doesn't have. Those are the specs that matter once the grid actually drops or your setup outgrows the box you bought.
So this isn't really AC180-versus-DELTA-3-Plus. It's daily-use battery against outage-and-growth insurance. The AC180 wins the first job outright. The DELTA 3 Plus wins the second, and by more than its price tag suggests.
What the Numbers Reveal
Each conclusion stated first — the numbers behind it on one line, the full analysis below.
solar input
Weekend Camping needs 2,100Wh and neither unit clears it on one charge (DELTA 3 Plus at 241% of tank, AC180 at 214%), so a multi-day trip forces a mid-trip solar recharge on both. That's exactly where the DELTA 3 Plus's doubled solar input turns into hours saved, not just a bigger number on a spec sheet.
The AC180 weighs 35.3 lbs against the DELTA 3 Plus's 27 lbs — an 8.3-lb differenceThe DELTA 3 Plus accepts up to 1,000W of solar input against the AC180's 500W — double the input
Why it mattersBuyers doing multi-day off-grid trips who'll actually recharge from panels mid-trip should weight the DELTA 3 Plus's solar headroom over the AC180's lower price; buyers who always recharge from a wall outlet can ignore this and take the cheaper, bigger AC180.
AC180 owners report a more predictable pattern — fans that stay quiet at idle and only get aggressive under real charging loadB1 — while DELTA 3 Plus owners describe fans cycling without an obvious load trigger. The DELTA 3 Plus is still the quieter unit by spec, but it's the less predictable one in practice.
The DELTA 3 Plus is rated at 30dB against the AC180's 40dB — a 10dB spec advantageOwners report the DELTA 3 Plus's fans activate even at low loads and cycle erratically, undercutting that ratingA1A2
Why it mattersBuyers who need genuinely quiet operation next to a bed — CPAP, a nursery — should treat the DELTA 3 Plus's 30dB number as optimistic until EcoFlow ships the firmware fix reviewers are expectingA4.
These aren't marginal wins. A 20ms standby switchover is long enough for some compressor loads to feel the gap, and 2,700W of surge sits close enough to a fridge-plus-something-else startup spike to matter, where the DELTA 3 Plus's extra 900W is real margin.
The DELTA 3 Plus switches over in 10ms against the AC180's 20msThe DELTA 3 Plus carries 3,600W of surge capacity against the AC180's 2,700W — 900W more headroomThe DELTA 3 Plus supports true expansion batteries; the AC180 is a closed system
Why it mattersBuyers protecting sensitive electronics or fridge-class loads during outages, or planning to grow their setup, should pay the $200 premium for the DELTA 3 Plus's inverter and expansion path.
Capacity
None of the DELTA 3 Plus's outage-specific advantages — faster switchover, more surge, expansion — help if the unit runs out before the day does. For a daily desk-battery use case, the AC180's bigger, cheaper tank is simply the better fit.
The AC180 holds 128Wh more capacity than the DELTA 3 Plus (1,152Wh vs 1,024Wh) for $200 lessRemote Workday needs 910Wh: the AC180 covers it at 93% of its tank, the DELTA 3 Plus needs 105% and falls short
Why it mattersBuyers running this as an everyday power source rather than occasional backup should buy the AC180 and pocket the $200.
The specific dimensions that decide these two units — everything else is a tie.
Portability & Form Factor
Selected because: Weight favors the DELTA 3 Plus modestly, but solar input speed is the sharper portability-adjacent gap.
weight
Weight moves in the DELTA 3 Plus's favor by 8.3 lbs — 27 against the AC180's 35.3 — real enough to matter on stairs or a tailgate, but not the deciding factor on its own.
Solar input is the more consequential spec here: the DELTA 3 Plus's 1,000W ceiling doubles the AC180's 500W, which matters most exactly when you're off-grid and the battery you're carrying is also the one you have to refill from a panel.
What the Specs Don't Tell You
Selected because: Switchover speed, surge headroom, and the expansion gap are the clearest, most spec-true tiebreakers.
rated cycles
The DELTA 3 Plus clears three gotchas outright: it switches over in 10ms against the AC180's 20ms, carries 900W more surge headroom, and is the only one of the two that genuinely expands — the AC180 tops out at 1,152Wh forever.
None of that matters if you never lose power or never grow past one unit. But a 20ms standby switchover is enough for some compressor loads to feel the gap, and a fixed ceiling is a real constraint the day your setup needs more than 1,152Wh.
Your Life, Your Pick
Selected because: Remote Workday is the one modeled day the AC180's bigger tank actually wins outright.
Remote Workday is the scenario that actually separates these two: the AC180 finishes at 93% of its tank, the DELTA 3 Plus needs 105% and doesn't make it through on one charge. That's the bigger-tank math showing up in a real day, not a spec sheet.
CPAP Overnight and Tailgate Party are comfortable for either unit — 37% and 33% for CPAP, 77% and 68% for Tailgate — so neither of those jobs alone justifies the price gap in either direction.
Lifetime Value
Selected because: AC180 is cheaper both upfront and per lifetime kWh — worth spelling out plainly.
cost / lifetime kWh
The AC180 costs $200 less and still lands at a lower cost per lifetime kWh — $0.12 against the DELTA 3 Plus's $0.17 — despite the DELTA 3 Plus's higher 4,000-cycle rating against the AC180's 3,500. The AC180's bigger tank per cycle wins that math.
Warranty-year cost tells the same story: $100 a year for the AC180 against $140 for the DELTA 3 Plus, both backed by 5-year warranties. If ownership cost is the only variable, the AC180 wins it outright.
Strengths & trade-offs
EcoFlow DELTA 3 Plus
Strengths
- +Lighter by 8.3 lb
- +Faster solar charging
Trade-offs
- –Substantially more expensive (+$190) than the AC180.
BLUETTI AC180
Strengths
- +Costs $190 less
- +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 six 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 can fully handle this scenario (needs 2,100Wh). You'd need a higher-capacity station or to cut back on usage.
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 can fully handle this scenario (needs 1,645Wh). You'd need a higher-capacity station or to cut back on usage.
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
Either unit
Both are wildly overqualified for CPAP. You're using 37% or less. Save your money and buy whichever is cheaper; the extra capacity is completely wasted on a 40W overnight load. Put the savings toward a second battery for multi-night trips.
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
AC180
The AC180 finishes a modeled workday with a real cushion at 93% of its tank. The DELTA 3 Plus needs 105% — it won't make it through on a single charge, purely because its tank is 128Wh smaller.
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
Either unit
Both handle game day easily. Since capacity isn't the deciding factor, consider weight: the lighter unit is easier to load into a truck bed. Also check if either has Bluetooth speaker-level noise. Fan sound matters in social settings.
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 can fully handle this scenario (needs 4,685Wh). You'd need a higher-capacity station or to cut back on usage.
Battery budget usedlower = more headroom
LOAD Mini-Fridge 150W×24h · Laptop 60W×4h · Phone Charger 15W×3h · LED Lights 40W×5h · Fan 75W×8h
The Load Test
RUNTIME = (Wh × 0.85) ÷ LOAD
None of the six 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: AC180 runs 4.8h vs 4.2h.
$499 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 0–65.3hComfort & Convenience
Makes off-grid life actually enjoyablescale 0–13.1hHigh-Draw Appliances
These reveal the real limitsscale 0–1h¹ 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 14, 2026
Verdict: the EcoFlow DELTA 3 Plus
Take the DELTA 3 Plus if outage resilience or future capacity growth matters: it switches over in 10ms against the AC180's 20ms, carries 900W more surge headroom (3,600W vs 2,700W), doubles the AC180's solar input (1,000W vs 500W), and is the only one of these two that actually expands. That's a real, structural set of advantages worth the $200 premium for anyone protecting sensitive gear or planning to grow their setup. But the AC180 is the better default for most people: it's $200 cheaper, holds 128Wh more capacity, and lands at $0.12 per lifetime kWh against $0.17 — and it's the one that actually finishes a Remote Workday (93% of its tank against the DELTA 3 Plus's 105%, which falls short). If you're buying this to sit on a shelf and run a day of desk work off, get the AC180.
Editor-assigned confidence, based on cited owner research and spec analysis.
List prices as of July 14, 2026. The links below open EcoFlow's and BLUETTI's current prices.
$689.00 list · direct from EcoFlow
or check the AC180 price$499.00 list
Written by Ian Schneider, Solar & Off-Grid Tester · Station Arena Test Desk · Updated July 14, 2026
Measured Data
Benchmark scores and the full spec record, side by side.
Benchmark scores
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, DELTA 3 Plus rates 4.4/5 (65th percentile of 24 Everyday-class units), and AC180 rates 4.1/5 (48th percentile of 24 Everyday-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.
One Of These Grows. One Is Final.
The DELTA 3 Plus takes true expansion batteries and grows past 1,024Wh without replacing the base unit. The AC180 is sealed at 1,152Wh for life — a bigger starting tank, but a hard ceiling.
Surge Power: Inverter Quality Indicator
The DELTA 3 Plus has a 2× surge-to-continuous ratio vs the AC180's 1.5×. A higher ratio (≥2×) means the inverter handles motor startup surges better. That's critical for fridges, AC compressors, and power tools that briefly draw 2-3× their rated wattage. The AC180 may trip when starting these appliances even though its continuous wattage looks sufficient.
10ms vs 20ms — Line-Interactive Beats Standby
The DELTA 3 Plus's line-interactive design switches over in 10ms; the AC180's standby design takes 20ms. Most gear never notices, but anything genuinely sensitive to a power gap benefits from the faster number.
Warranty Value Comparison
The AC180 gives you 10 years of warranty per $1,000 spent, vs the DELTA 3 Plus's 7.3 years. That's 1.4× more coverage per dollar. An underrated factor if you're keeping this unit for years.
Full record above — the Test Desk pick is the DELTA 3 Plus.
Check DELTA 3 Plus price →or check the AC180 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
The AC180 wins on both sticker price and long-term value. At $0.12/kWh over its lifetime, it's meaningfully cheaper to own. Clear value winner.
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
US-based phone/email/chat support (1-800-368-8604). Experiences are polarized — 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 — 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. Supports up to 180kWh modular expansion with DELTA Pro Ultra X.
Worth knowing
The Oct 2025 DELTA Max 2000 recall (overheating/fire risk, 6 incidents) is worth noting. Also 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 (Apex 300, 3072Wh). Includes specialized products: vehicle solar hubs, sodium-ion cold-weather units, and balcony storage systems.
Support
The most inconsistent support in the space. Heavily email-based with China timezone delays. Some users get smooth, efficient service; others report weeks of troubleshooting runarounds, being offered discounts on new units instead of repairs, and confusing third-party purchase claim processes. Buying direct from Bluetti's website tends to produce better support outcomes.
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
Among the best capacity-to-price ratios available — 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. Full LFP standardization across lineup (3,500-6,000+ cycles). Dual-voltage (120V/240V) in 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 positions itself as a mid-to-premium brand with stronger support infrastructure, while BLUETTI competes on value. The question is whether the EcoFlow ecosystem and support premium is worth it for your use case.
Growth path
DELTA 3 Plus
EXPANDABLESupports EcoFlow expansion batteries, so you can add capacity later without replacing the base unit — useful if your needs may climb past 1,024Wh.
Accepts up to 1,000W of solar. Enough for a serious multi-panel array.
Generous port selection supports complex multi-device setups.
Expansion batteries are EcoFlow-specific. You're investing in the EcoFlow ecosystem.
AC180
FIXED CAPACITYFixed at 1,152Wh, with no expansion — so size it for your needs up front rather than planning to add capacity later.
Accepts up to 500W of solar. Suitable for a 1-2 panel setup.
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 DELTA 3 Plus's expandability as a straight win here: it starts at 1,024Wh, below the AC180's 1,152Wh, so a first expansion battery largely buys back capacity the AC180 already includes. It only pulls ahead if you'd grow past 1,152Wh — short of that, the AC180'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 DELTA 3 Plus
The DELTA 3 Plus's headline strength is speed: reviewers consistently point to fast recharge times and a UPS switchover quick enough that connected gear doesn't notice the outageA3. That's the same 10ms number that separates it from the AC180 on paper, and owner testing backs it up.
The catch is fan behavior. Owners report the fans kick on even at low loads and cycle erratically rather than staying off the way the 30dB spec impliesA1, and that erratic cycling has been flagged as a real overheating risk under heavy loadsA2. It's the kind of flaw EcoFlow has fixed via firmware before, and reviewers expect the same hereA4, but as shipped, the quiet number on the spec sheet needs an asterisk.
“Otherwise well-designed, with very fast recharge times and a seamless sub-10ms UPS switchover for uninterrupted power.”
Sources
thesolarlab.com
BLUETTI AC180
Owner sentiment on the AC180 is split on noise: some find it fairly quiet a few feet away, others call the fans aggressive and loud specifically while charging, and BLUETTI's answer is a silent charging mode that trades speed for quietB1. Weight is the other recurring complaint — at 35.3 lbs, one reviewer named it their single biggest frustration moving the unit aroundB2.
What keeps it recommended anyway is value: reviewers call it the definition of bang-for-buck in the mid-range, backed by 3,500-plus rated cycles on real LiFePO4 cells and a 5-year warrantyB3B4. Nobody's calling it the most refined unit here, but nobody disputes it's the cheapest good one.
“Fan noise draws mixed reports — some find it fairly quiet from a few feet, others call the fans aggressive and loud, especially during charging; a silent charging mode caps the noise by limiting charge speed.”
Sources
outdoorgearlab.com · storagereview.com · kenrockwell.com · voltagebasics.com · bluettipower.com · backuppowerhub.com · solarwithwatts.com · pcworld.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 DELTA 3 Plus's headline weakness is fan behavior — fans run even at low load and cycle erratically, undercutting its quiet-UPS marketing. [DELTA 3 Plus · 3 entries]
- Best-in-class value and capacity-per-dollar are the consistent praise; the weight and aggressive fans under load are the recurring caveats. [AC180 · 2 entries]
- A1
“Marketed as near-silent, but real-world fan performance is a significant flaw: the fans activate even under low loads and cycle on and off erratically, which limits its effectiveness as a quiet UPS.”
T3 — EcoFlow DELTA 3 Plus review: Lightning-fast charging with a noisy flaw; thesolarlab.com — DELTA 3 Plus Review · 2026 · [negative]
- A2
“Part of why it stays quiet is that the internal fans aren't always doing their job properly — the erratic cycling raises the risk of the unit overheating when running heavy loads.”
thesolarlab.com — EcoFlow DELTA 3 Plus Review: Amazing, but One Big Quirk? · 2026 · [negative]
- A3
“Otherwise well-designed, with very fast recharge times and a seamless sub-10ms UPS switchover for uninterrupted power.”
T3 / thesolarlab.com — DELTA 3 Plus reviews · 2026 · [positive]
- A4
“Reviewers note EcoFlow should be able to resolve the fan behavior with a software update, as it has done for other power stations after release.”
thesolarlab.com — DELTA 3 Plus Review · 2026 (dated claim — may be partially addressed by firmware) · [mixed]
- B1
“Fan noise draws mixed reports — some find it fairly quiet from a few feet, others call the fans aggressive and loud, especially during charging; a silent charging mode caps the noise by limiting charge speed.”
outdoorgearlab.com / storagereview.com — BLUETTI AC180 review · 2025-2026 · [mixed]
- B2
“At roughly 35-37 lbs it's heavy for its class — one reviewer named the weight their biggest frustration when moving it around.”
kenrockwell.com / voltagebasics.com — AC180 review · 2025-2026 · [negative]
- B3
“Quality LiFePO4 cells rated for 3,500-plus full cycles before capacity degrades to 80%, backed by a 5-year warranty.”
bluettipower.com / backuppowerhub.com — AC180 review · 2025-2026 · [positive]
- B4
“The definition of bang for buck — not the lightest or smartest, but the most raw power and capacity for the price; widely called the best value in the mid-range at around $499.”
solarwithwatts.com / pcworld.com — BLUETTI AC180 review · 2025-2026 · [positive]
Research compiled July 14, 2026.
Who Should Buy Which
Buy the DELTA 3 Plus if you…
- →You're buying this as outage insurance and want the fastest switchover and the most surge headroom in this pair.
- →You expect your power needs to grow — the DELTA 3 Plus's expansion path means you won't be buying a second unit later.
Buy the AC180 if you…
- →You want the bigger, cheaper tank and a lower cost per lifetime kWh, and you're not chasing the DELTA 3 Plus's outage-specific advantages.
- →Your real use case is a full remote workday on one charge — the AC180 finishes it at 93%, the DELTA 3 Plus doesn't.
If neither fits
If your actual need is a two-night camping trip (about 2,100Wh) or an 8-hour multi-appliance blackout (about 1,645Wh), both fall short here — they land between 168% and 241% of what's needed. Look at a larger-capacity unit in either brand's lineup instead.
The Bottom Line
The AC180 is the cheaper, bigger-tank default — $499 for 1,152Wh against $699 for 1,024Wh, at a lower cost per lifetime kWh despite the DELTA 3 Plus's higher cycle count. For a unit that mostly sits and runs a workday, that's the easier buy.
The DELTA 3 Plus earns its $200 back the day the power actually drops: a twice-as-fast switchover, 900W more surge headroom, double the solar input, and an expansion path the AC180 simply doesn't have. Buy it for what happens on the bad day, not the average one.
Frequently Asked Questions
Answers drawn from the spec record and cited owner research.
Which is cheaper, the DELTA 3 Plus or the AC180?
The AC180, by $200 — $499 against $699 — and it also holds 128Wh more capacity (1,152Wh vs 1,024Wh). On price and capacity alone it's the easy pick.
Which one switches over faster during a power outage?
The DELTA 3 Plus, at 10ms against the AC180's 20ms standby switchover. Most household gear won't notice either gap, but anything sensitive to interruption benefits from the faster number.
Does the AC180 expand like the DELTA 3 Plus does?
No. The AC180 is a closed system capped at 1,152Wh forever, while the DELTA 3 Plus supports true expansion batteries that add capacity without replacing the base unit.
Is the DELTA 3 Plus actually quieter than the AC180?
On paper, yes — 30dB against 40dB. In practice, owners report the DELTA 3 Plus's fans activate even at low loads and cycle erratically, so the real-world gap is smaller than the spec sheet suggests, and it's a flaw reviewers expect EcoFlow to fix via firmware.
Which one should I actually buy?
Take the AC180 if you want the cheaper, bigger-tank unit for daily use and don't need outage-specific speed. Take the DELTA 3 Plus if you're buying this as blackout insurance or expect to expand capacity later — the faster switchover, extra surge headroom, and real expansion path are worth the $200 for that job.
Where to buy
EcoFlow DELTA 3 PlusPick
$689.00
$689.00 list · direct from EcoFlow
BLUETTI AC180
$499.00
$499.00 list · direct from BLUETTI
Prices may vary by retailer and are subject to change.