Head-to-head test
EcoFlow DELTA 3 Ultra Plus vs BLUETTI AC500 + 2×B300K
Real-world runtimes, scenario verdicts, and ownership costs compared — which wins for your use case.
Full profiles: EcoFlow DELTA 3 Ultra Plus → · BLUETTI AC500 + 2×B300K →
Written by Gunner GustafsonUpdated
Whole-Home Backup Tester, Station Arena Test Desk
Spec deltas
The EcoFlow DELTA 3 Ultra Plus (3,072Wh) and BLUETTI AC500 + 2×B300K (5,530Wh) 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? The AC500 + 2×B300K has a slight edge, but the margin is close enough that your use case should break the tie.
What the spec gap means in practice: the AC500 + 2×B300K's 5,000W inverter has the headroom for a window AC, a full-size fridge, and power tools. The DELTA 3 Ultra Plus's 3,600W inverter still runs most single appliances; the AC500 + 2×B300K's real edge is surge headroom for the biggest motor starts and stacking several heavy loads at once. On stamina, the AC500 + 2×B300K keeps a fridge alive for roughly 31 hours vs the DELTA 3 Ultra Plus's 17 hours. The cost? Portability. At 196.1 lbs, the AC500 + 2×B300K is spread across boxes you site once and leave. The DELTA 3 Ultra Plus at 74.3 lbs is more manageable, though still not light.
Pick the AC500 + 2×B300K if your primary use is 8-hour blackout or remote workday. Go with the DELTA 3 Ultra Plus if you primarily need it for weekend camping or tailgate party. 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 Plus
With a massive 3,600W output (and 7,200W surge), the DELTA 3 Ultra Plus can run high-wattage appliances like space heaters, hair dryers, and electric grills without tripping. Weighing in at 74.3 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 $0.52 per watt-hour, it's one of the most cost-effective options on the market.
Strengths
- +Lighter by 121.8 lb
- +Longer warranty
Trade-offs
- –Weaker inverter (-1,400W) limits appliance compatibility.
BLUETTI AC500 + 2×B300K
With a massive 5,000W output (and 10,000W surge), the AC500 + 2×B300K can run high-wattage appliances like space heaters, hair dryers, and electric grills without tripping. Weighing in at 196.1 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
- +Higher AC output
- +Faster solar charging
Trade-offs
- –Significantly heavier (+121.8 lbs), making it harder to move.
- –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 Plus
The AC500 + 2×B300K at 196.1 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 Plus by default — and it earns it, covering the 2,100Wh with 511Wh to spare. Capacity was never the AC500 + 2×B300K'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
AC500 + 2×B300K
Both survive the night. The AC500 + 2×B300K finishes at 35% used with 3,056Wh left — 1.9 more nights like it. The DELTA 3 Ultra Plus 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 AC500 + 2×B300K doesn't publish a figure, so there's nothing to hold it to. Only the DELTA 3 Ultra Plus is still sold, so for a new buy it takes this by default; the AC500 + 2×B300K 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
AC500 + 2×B300K
The AC500 + 2×B300K clears the workday at 19% used, banking 3,791Wh — late work, extra calls, or a second laptop charge without arithmetic. The DELTA 3 Ultra Plus 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 Plus
The AC500 + 2×B300K at 196.1 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 Plus by default — and it earns it, covering the 670Wh with 1,941Wh to spare. Capacity was never the AC500 + 2×B300K'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
AC500 + 2×B300K
The DELTA 3 Ultra Plus doesn't finish — 2,611Wh usable against the 4,685Wh this needs leaves it 2,074Wh short, about 56% of the scenario covered. The AC500 + 2×B300K covers it with only 16Wh left — well under half a percent of what the day asks, so it finishes with nothing behind it.
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: AC500 + 2×B300K runs 22.9h 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 0–313.4hComfort & Convenience
Makes off-grid life actually enjoyablescale 0–62.7hHigh-Draw Appliances
These reveal the real limitsscale 0–4.7h¹ 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 withdrawn: the AC500 + 2×B300K is no longer sold
We picked the AC500 + 2×B300K, but it's been discontinued (BLUETTI now points buyers to the Apex 300 + B300K). The DELTA 3 Ultra Plus is still on sale, but that alone doesn't make it our pick. The comparison below is still accurate if you own either one.
Overall score margin: 4,799 vs 6,009 (−25.2%)
Written by Gunner Gustafson, Whole-Home Backup Tester · Station Arena Test Desk · Updated July 10, 2026
Black Friday · 25 days out
Price to beat:DELTA 3 Ultra Plus $1,499
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 Plus rates 4.9/5 (96th percentile of 28 Large-class units), and AC500 + 2×B300K rates 4.1/5 (47th percentile of 20 Home Backup-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 Plus (74.3 lbs) is manageable solo but heavier than a large checked suitcase. The AC500 + 2×B300K (196.1 lbs) is spread across its boxes — no single lift, but nothing you reposition on a whim. That's a 122 lb difference, and it is paid once — getting the heavier one into position, not every time you move it.
AC500 + 2×B300K: Power Lifting to 6,000W
The AC500 + 2×B300K has BLUETTI's Power Lifting mode, which runs a resistive appliance rated up to 6,000W from its 5,000W inverter. It does that by delivering less power than the appliance asks for, not more than the inverter has: the heater still works, it just heats more slowly. Two things follow. BLUETTI scopes the mode to purely resistive loads — a heater, a kettle, an incandescent lamp — so it does nothing for a fridge compressor, a pump or a power tool; for motor loads the figure to read is the AC500 + 2×B300K's separate 10,000W surge peak, not this one. And it is not a reason to size down, because running a load that big from 5,530Wh is a short session either way. Genuinely useful if a heater or a kettle is why you're buying; beside the point otherwise. The DELTA 3 Ultra Plus publishes no equivalent.
UPS Switchover: ≤10ms vs ≤20ms
Both list a UPS mode, at different rated speeds. The DELTA 3 Ultra Plus is rated ≤10ms — quick enough on paper that desktop PCs and routers should ride through, treating that as the rating it is. The AC500 + 2×B300K 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 Plus is covered for 5 years against the AC500 + 2×B300K's 4 years. An underrated factor if you're keeping this unit for years.
AC500 + 2×B300K: Noise Level Not Disclosed
The DELTA 3 Ultra Plus publishes its noise level (30dB); the AC500 + 2×B300K doesn't publish one. That isn't evidence the AC500 + 2×B300K 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 Plus'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 AC500 + 2×B300K before deciding.
Ownership Analysis
What happens after you buy — true cost of ownership, brand trust, and growth potential.
Lifetime value
Service lifeyears at one full cycle per day
Lifetime energy delivered
Cost per delivered kWh
│ warranty ends · Reaching the cycle rating means ~80% capacity remains — degraded, not dead.
Analyst note
The AC500 + 2×B300K 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 Plus works out at $0.13/kWh over its rated life. If you already own the AC500 + 2×B300K, the hardware comparison still holds: over its rated life the DELTA 3 Ultra Plus delivers about 12,288 kWh and the AC500 + 2×B300K about 19,355 kWh. One caution on the lifespan row: the DELTA 3 Ultra Plus takes longer to reach its cycle rating, but a cycle moves a different amount of energy on each unit — the AC500 + 2×B300K 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 Plus
EXPANDABLESupports EcoFlow expansion batteries, so you can add capacity later without replacing the base unit — useful if your needs may climb past 3,072Wh.
Accepts up to 1,600W 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 EcoFlow-specific. You're investing in the EcoFlow ecosystem.
AC500 + 2×B300K
EXPANDABLESupports BLUETTI expansion batteries, so you can add capacity later without replacing the base unit — useful if your needs may climb past 5,530Wh.
Accepts up to 3,000W 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 AC500 + 2×B300K is no longer sold (BLUETTI points owners to the Apex 300 + B300K). That leaves the DELTA 3 Ultra Plus: it starts at 3,072Wh and takes EcoFlow expansion batteries, so the ceiling moves if your needs do. The AC500 + 2×B300K's expandability still matters if you already own one, but it isn't a reason to pick it over the DELTA 3 Ultra Plus.
The Bottom Line
The full picture comes down to this. The AC500 + 2×B300K 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 DELTA 3 Ultra Plus wins in the scenarios that match your life, it's the right choice regardless of aggregate scores.
If neither the DELTA 3 Ultra Plus nor the AC500 + 2×B300K 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 2,458Wh capacity difference actually affect daily use?
The AC500 + 2×B300K's 5,530Wh battery keeps a mini-fridge running for roughly 31 hours vs the DELTA 3 Ultra Plus's 17 hours. Both can handle a full 8-hour blackout setup (fridge + router + lights + phone charging ≈ 1,645Wh), but the AC500 + 2×B300K 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 AC500 + 2×B300K'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 AC500 + 2×B300K, or is the DELTA 3 Ultra Plus the only portable option?
Neither is "portable" in any hiking sense. The DELTA 3 Ultra Plus (74.3 lbs) and the AC500 + 2×B300K (196.1 lbs) are both appliances you place and leave. The 121.8-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 AC500 + 2×B300K accepts 3,000W vs the DELTA 3 Ultra Plus's 1,600W 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 2.6 hours for the AC500 + 2×B300K and 2.7 hours for the DELTA 3 Ultra Plus. That gap widens on cloudy days, when the AC500 + 2×B300K'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 AC500 + 2×B300K's advantage is substantial.
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 Plus or the AC500 + 2×B300K?
We'd have said the AC500 + 2×B300K, but it is no longer sold. The DELTA 3 Ultra Plus is still on sale, but that alone doesn't make it our pick. The comparison on this page is still accurate if you own either one.
Brand matchup
EcoFlow vs BLUETTI: measured across every matchup →Where to buy
EcoFlow DELTA 3 Ultra Plus
$1,599.00
$1,599.00 · direct from EcoFlow
Last checked 2 hours ago. Prices move — check before you buy.
BLUETTI AC500 + 2×B300K
Sold out at BLUETTI
Prices may vary by retailer and are subject to change.