Head-to-head test
EcoFlow DELTA 3 Ultra vs BLUETTI AC300 + 4×B300
Real-world runtimes, scenario verdicts, and ownership costs compared — which wins for your use case.
Full profiles: EcoFlow DELTA 3 Ultra → · BLUETTI AC300 + 4×B300 →
Written by Gunner GustafsonUpdated
Whole-Home Backup Tester, Station Arena Test Desk
Spec deltas
The EcoFlow DELTA 3 Ultra (3,072Wh) and BLUETTI AC300 + 4×B300 (12,288Wh) sit in different weight classes. The real question: do your power needs justify the larger unit, or would you be overpaying for capacity that sits unused? We'd buy the DELTA 3 Ultra.
What the spec gap means in practice: the AC300 + 4×B300's 3,000W inverter has the headroom for a window AC, a full-size fridge, and power tools. The DELTA 3 Ultra's 3,600W inverter still runs most single appliances; the AC300 + 4×B300's real edge is surge headroom for the biggest motor starts and stacking several heavy loads at once. On stamina, the AC300 + 4×B300 keeps a fridge alive for roughly 70 hours vs the DELTA 3 Ultra's 17 hours. The cost? Portability. At 367.2 lbs, the AC300 + 4×B300 is spread across boxes you site once and leave. The DELTA 3 Ultra at 72.1 lbs is more manageable, though still not light.
Pick the DELTA 3 Ultra if your primary use is weekend camping or tailgate party. Go with the AC300 + 4×B300 if you primarily need it for 8-hour blackout or remote workday. Keep scrolling for the full breakdown. The scenario verdicts below hold a few surprises.
Bench Notes
What each unit does well, where it falls short, and the trade-offs that matter.
EcoFlow DELTA 3 Ultra
With a massive 3,600W output (and 7,200W surge), the DELTA 3 Ultra can run high-wattage appliances like space heaters, hair dryers, and electric grills without tripping. Weighing in at 72.1 lbs, this is not a unit you want to carry far. It's best suited as a stationary backup or RV companion. A standout feature is the value proposition: at roughly $0.46 per watt-hour, it's one of the most cost-effective options on the market.
Strengths
- +Lighter by 295.1 lb
- +Higher AC output
- +Longer warranty
Trade-offs
- –Sealed capacity — the AC300 + 4×B300 can add batteries to grow past 3,072Wh; this one can't.
BLUETTI AC300 + 4×B300
With a massive 3,000W output (and 6,000W surge), the AC300 + 4×B300 can run high-wattage appliances like space heaters, hair dryers, and electric grills without tripping. Weighing in at 367.2 lbs, this is not a unit you want to carry far. It's best suited as a stationary backup or RV companion.
Strengths
- +Larger battery capacity
- +Faster solar charging
Trade-offs
- –Significantly heavier (+295.1 lbs), making it harder to move.
- –Weaker inverter (-600W) limits appliance compatibility.
- –Very heavy unit that may be difficult for one person to lift.
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
DELTA 3 Ultra
The AC300 + 4×B300 at 367.2 lbs is not a take-along — it rolls off a truck bed if it travels at all, so this scenario belongs to the DELTA 3 Ultra by default — and it earns it, covering the 2,100Wh with 511Wh to spare. Capacity was never the AC300 + 4×B300's problem here; getting to a campsite was.
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
AC300 + 4×B300
Both survive the night. The AC300 + 4×B300 finishes at 16% used with 8,800Wh left — 5.3 more nights like it. The DELTA 3 Ultra finishes at 63% with 966Wh, 59% of a second night. If your outages tend to run past one evening, that difference is the whole argument between them.
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
A CPAP is about 40W for eight hours, so both of these cover the night several times over — capacity isn't the question here. What would separate them is fan noise, but AC300 + 4×B300 doesn't publish a figure, so there's nothing to hold it to. Only the DELTA 3 Ultra is still sold, so for a new buy it takes this by default; the AC300 + 4×B300 is worth weighing on weight and fan noise only if you already own one.
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
AC300 + 4×B300
The AC300 + 4×B300 clears the workday at 9% used, banking 9,535Wh — late work, extra calls, or a second laptop charge without arithmetic. The DELTA 3 Ultra at 35% also finishes, with 1,701Wh of slack for the unplanned.
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
DELTA 3 Ultra
The AC300 + 4×B300 at 367.2 lbs is not a take-along — it rolls off a truck bed if it travels at all, so this scenario belongs to the DELTA 3 Ultra by default — and it earns it, covering the 670Wh with 1,941Wh to spare. Capacity was never the AC300 + 4×B300's problem here; getting to a tailgate was.
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
AC300 + 4×B300
The DELTA 3 Ultra doesn't finish — 2,611Wh usable against the 4,685Wh this needs leaves it 2,074Wh short, about 56% of the scenario covered. The AC300 + 4×B300 covers it with 5,760Wh to spare.
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 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: AC300 + 4×B300 runs 51h vs 12.7h.
Planning for more than this? Describe your whole setup and get it sized →
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 0–696.3hComfort & Convenience
Makes off-grid life actually enjoyablescale 0–139.3hHigh-Draw Appliances
These reveal the real limitsscale 0–10.4h¹ 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 10, 2026
Verdict: the DELTA 3 Ultra
The DELTA 3 Ultra takes it on balance: 600W more output than the AC300 + 4×B300, against 9,216Wh less capacity. It is also 295.1 lbs lighter.
Today the DELTA 3 Ultra is $1,299, $100 under its typical $1,399. The verdict weighs typical prices, not today's. Prices checked 28 days ago.
Overall score margin: 4,710 vs 8,742 (−85.6%)
List prices as of July 10, 2026. The links below open EcoFlow's current price.
$1,299.00 · direct from EcoFlow
down from $1,399 · 7% below usual
Last checked 28 days ago. Prices move — check before you buy.
Written by Gunner Gustafson, Whole-Home Backup Tester · Station Arena Test Desk · Updated July 10, 2026
Black Friday · 26 days out
Price to beat:DELTA 3 Ultra $1,199
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, RV Living, 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.
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 Ultra rates 4.7/5 (85th percentile of 27 Large-class units), and AC300 + 4×B300 rates 3.3/5 (1st percentile of 29 Whole-Home / Off-Grid-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.
Weight Reality Check
Neither unit is grab-and-go. The DELTA 3 Ultra (72.1 lbs) is manageable solo but heavier than a large checked suitcase. The AC300 + 4×B300 (367.2 lbs) is spread across its boxes — no single lift, but nothing you reposition on a whim. That's a 295 lb difference, and it is paid once — getting the heavier one into position, not every time you move it.
DELTA 3 Ultra: Fixed Capacity
The DELTA 3 Ultra is sealed at 3,072Wh, and that is the ceiling. Normally the counterpoint would be that the AC300 + 4×B300 can add expansion batteries, but that isn't a live option here: the AC300 + 4×B300 is no longer sold, and BLUETTI points owners to the Apex 300 + 2*B500K. For a new purchase the expansion question doesn't arise between these two, so the DELTA 3 Ultra's fixed 3,072Wh is simply what you get.
UPS Switchover: ≤10ms vs ≤20ms
Both list a UPS mode, at different rated speeds. The DELTA 3 Ultra is rated ≤10ms — quick enough on paper that desktop PCs and routers should ride through, treating that as the rating it is. The AC300 + 4×B300 is rated ≤20ms — fine on paper for routers and most electronics; the fussiest PC power supplies sit right at this line. If a computer with unsaved work is the thing being protected, the stated class is worth the attention; nothing here is a lab result.
Warranty: 5 Years vs 4
The DELTA 3 Ultra is covered for 5 years against the AC300 + 4×B300's 4 years. An underrated factor if you're keeping this unit for years.
AC300 + 4×B300: Noise Level Not Disclosed
The DELTA 3 Ultra publishes its noise level (30dB); the AC300 + 4×B300 doesn't publish one. That isn't evidence the AC300 + 4×B300 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 DELTA 3 Ultra's 30dB as the only published number on the table — a spec-sheet figure, not a measurement — and look for hands-on reports of the AC300 + 4×B300 before deciding.
Full record above — the Test Desk pick is the DELTA 3 Ultra.
Check DELTA 3 Ultra price →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
The AC300 + 4×B300 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 DELTA 3 Ultra works out at $0.11/kWh over its rated life. If you already own the AC300 + 4×B300, the hardware comparison still holds: over its rated life the DELTA 3 Ultra delivers about 12,288 kWh and the AC300 + 4×B300 about 43,008 kWh. One caution on the lifespan row: the DELTA 3 Ultra takes longer to reach its cycle rating, but a cycle moves a different amount of energy on each unit — the AC300 + 4×B300 still delivers more over its shorter horizon. Years measure wear, not usefulness.
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. 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 — flagship paths, not line-wide features.
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
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. 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 — 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 — 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 Ultra
FIXED CAPACITYFixed at 3,072Wh — a sealed, complete system rather than a starting point. There's no expansion port, so that figure is the ceiling: check it against your longest unplugged stretch before you buy.
Accepts up to 800W of solar. Suitable for a 1-2 panel setup.
Adequate ports for most setups, but heavy users may want a power strip.
AC300 + 4×B300
EXPANDABLESupports BLUETTI expansion batteries, so you can add capacity later without replacing the base unit — useful if your needs may climb past 12,288Wh.
Accepts up to 2,400W of solar. Enough for a serious multi-panel array.
Adequate ports for most setups, but heavy users may want a power strip.
Expansion batteries are BLUETTI-specific. You're investing in the BLUETTI ecosystem.
Realistic full solar rechargeat 70% of rated panel output — see methodology
Analyst note
Growth only counts if you can still buy in, and the AC300 + 4×B300 is no longer sold (BLUETTI points owners to the Apex 300 + 2*B500K). That leaves the DELTA 3 Ultra: it is sealed at 3,072Wh, so buy the size that covers you now. The AC300 + 4×B300's expandability still matters if you already own one, but it isn't a reason to pick it over the DELTA 3 Ultra.
The Bottom Line
The full picture comes down to this. The DELTA 3 Ultra edges ahead on our overall analysis, but the margin is narrow enough that your specific use case should drive the decision. Review the scenario verdicts above — if the AC300 + 4×B300 wins in the scenarios that match your life, it's the right choice regardless of aggregate scores.
If neither the DELTA 3 Ultra nor the AC300 + 4×B300 feels like the right fit, your power needs probably sit outside what these two target. For lighter use — weekend camping or phone/laptop charging — you'd be overpaying for capacity you'll rarely tap. Consider a unit in the 500–1,500Wh range instead. Prices on portable power stations fluctuate frequently. Both EcoFlow and BLUETTI discount regularly, so check the current price before committing. Prime Day and Black Friday pricing typically drops 20-30%.
Frequently Asked Questions
Answers drawn from the spec record and cited owner research.
How does the 9,216Wh capacity difference actually affect daily use?
The AC300 + 4×B300's 12,288Wh battery keeps a mini-fridge running for roughly 70 hours vs the DELTA 3 Ultra's 17 hours. Both can handle a full 8-hour blackout setup (fridge + router + lights + phone charging ≈ 1,645Wh), but the AC300 + 4×B300 finishes with significantly more margin. That matters if conditions aren't ideal or the outage runs long. What specs don't mention: runtime drops 20-30% in cold weather (below 32°F/0°C) as battery chemistry slows down. The AC300 + 4×B300's extra capacity provides a critical cold-weather buffer. For occasional phone and laptop charging, both are overkill. This gap only matters for sustained, multi-appliance use.
Can I actually carry the AC300 + 4×B300, or is the DELTA 3 Ultra the only portable option?
Neither is "portable" in any hiking sense. The DELTA 3 Ultra (72.1 lbs) and the AC300 + 4×B300 (367.2 lbs) are both appliances you place and leave. The 295.1-lb difference matters when loading into a vehicle or moving between rooms, but that's about it. If true portability is your priority, look at units under 20 lbs in a different class entirely.
How fast can each unit recharge from solar panels in real conditions?
On paper, the AC300 + 4×B300 accepts 2,400W vs the DELTA 3 Ultra's 800W of solar input. What the spec sheet won't tell you: solar panels typically deliver only 60-80% of their rated output due to panel angle, cloud cover, and temperature. In realistic conditions, expect full recharge in about 7.3 hours for the AC300 + 4×B300 and 5.5 hours for the DELTA 3 Ultra. That gap widens on cloudy days, when the AC300 + 4×B300's higher input ceiling captures more of whatever sunlight is available. One more thing: summer gives you ~7 productive solar hours per day. Winter drops to ~4. If solar is your primary recharge method, the AC300 + 4×B300's advantage is substantial.
What if I need more capacity than the DELTA 3 Ultra's 3,072Wh later?
The DELTA 3 Ultra is sealed at 3,072Wh, so if you expect your needs to climb, the AC300 + 4×B300 is the more future-proof pick: it starts at 12,288Wh and adds BLUETTI-compatible batteries without replacing the base unit. That said, "not expandable" isn't a flaw on its own — if 3,072Wh comfortably covers your loads, the DELTA 3 Ultra is a complete unit, not a downgrade.
Is EcoFlow or BLUETTI more reliable for long-term ownership?
Both brands have strengths and trade-offs. EcoFlow: Mixed. 2-5 years depending on model. Some users report smooth claims; others report runarounds. Register your product to extend coverage. BLUETTI: 2-6 years depending on model (up to 10 years on home backup systems). Response times vary significantly. Some reports of units being deemed unrepairable with no parts available for older models. One piece of advice from the power station community: regardless of brand, buy from Costco or Amazon. Their return policies provide a safety net that manufacturer warranties alone can't match, especially for a product you'll rely on in emergencies. Both brands use LFP (lithium iron phosphate) batteries in their current lineup, the most proven chemistry for longevity and safety.
Bottom line: should I buy the DELTA 3 Ultra or the AC300 + 4×B300?
We'd buy the DELTA 3 Ultra. The AC300 + 4×B300 is no longer sold, so there is no price to weigh it against; the comparison on this page still helps if you own one.
Brand matchup
EcoFlow vs BLUETTI: measured across every matchup →Where to buy
EcoFlow DELTA 3 UltraPick
$1,299.00
$1,299.00 · direct from EcoFlow
down from $1,399 · 7% below usual
Last checked 28 days ago. Prices move — check before you buy.
BLUETTI AC300 + 4×B300
Sold out at BLUETTI
Prices may vary by retailer and are subject to change.