Head-to-head test
EcoFlow DELTA 3 Ultra vs BLUETTI AC70P
Everything here turns on 734Wh, which is all the AC70P will really hand you: stay under that line and you keep $800 for nothing lost, cross it and you own a battery that quits in the middle of the job with nothing you can bolt on to save it.
Full profiles: EcoFlow DELTA 3 Ultra → · BLUETTI AC70P →
Written by Ian SchneiderUpdated
Solar & Off-Grid Tester, Station Arena Test Desk
$1,399.00 · direct from EcoFlow
Last checked 3 days ago. Prices move — check before you buy.
$499.00 · direct from BLUETTI
Last checked 3 days ago. Prices move — check before you buy.
Spec deltas
$1,299 buys 3,072Wh. $499 buys 864Wh. That's 3.6 times the energy for 2.6 times the money, which makes the expensive box the cheaper watt-hour ($0.42 against $0.58) and still leaves you writing a much bigger check.
The AC70P's 864Wh is really 734Wh, once the inverter takes its cut and you accept that nobody runs a pack to zero. Four of the six load lists on this page walk straight past that line: a camping weekend at 2,100Wh, an eight-hour outage at 1,645Wh, a remote workday at 910Wh, a van day at 4,685Wh. It clears the other two, a 320Wh CPAP night and a 670Wh tailgate, and it finishes the tailgate with 9% left in the tank.
Pulling the other way, the AC70P weighs 22.5 lb and the Ultra weighs 72.1. Neither one takes an expansion battery, so the choice is permanent in both directions. You can't grow the small one, and you can't shrink the big one.
What the Numbers Reveal
Each conclusion stated first — the numbers behind it on one line, the full analysis below.
Capacity
Run the remote workday against it. 910Wh is 35% of the Ultra and 124% of the AC70P, a 176Wh shortfall, and a shortfall like that shows up at four in the afternoon with the work still open. The buyer who went small to leave room to grow has nothing to add. The fix is a second power station, which spends the savings and leaves two boxes to store and charge instead of one.
DELTA 3 Ultra: 3,072Wh at $1,299, which is $0.42 per watt-hourAC70P: 864Wh at $499, which is $0.58 per watt-hourExpansion feasibility is No on each unit — neither accepts an add-on battery
Why it mattersIf one sitting on your list is likely to pass that line, the AC70P isn't a first step, so buy the Ultra now and stop planning an upgrade that doesn't exist.
solar input
For one appliance overnight, small and quick beats big and slow. A CPAP takes 320Wh a night, so the AC70P does two nights on a charge (734 ÷ 320) and an afternoon of panel time puts it back where it started. The Ultra runs the same CPAP eight nights without anyone unfolding a panel (2,611 ÷ 320), but on the day it does go flat, you're handing over most of a sunny day to get it back.
AC70P: 864Wh capacity, 500W solar input, 22.5 lbDELTA 3 Ultra: 3,072Wh capacity, 800W solar input, 72.1 lbCPAP Overnight draws 320Wh — 44% of the AC70P's usable energy, 12% of the Ultra's
Why it mattersIf the only load is a medical device and you already own a panel, take the 22.5 lb unit and keep the difference; if you want multiple nights of margin without ever touching a panel, take the Ultra.
weight
Now add the noise floor. The AC70P is rated 45 dBA under load against the Ultra's 30, and reviewers describe the Ultra's fans as unobtrusive even with the inverter pushed hardA1A2. So the box that's easy to walk to the tent is the box that will be working hardest, closest to you, in the smallest space you own. The quiet one is the one you have to plan a lift around.
AC70P: 22.5 lb; DELTA 3 Ultra: 72.1 lbWeekend Camping load list: 2,100Wh — 80% of the Ultra's usable energy, 286% of the AC70P'sRated noise: 45 dBA on the AC70P, 30 dBA on the Ultra
Why it mattersPark within a few steps of the tent and take the Ultra; carry it any real distance, or lift it alone twice a day, and shrink the trip down to what the small tank covers.
cost / lifetime kWh
That discount only exists if you spend it. At weekend use the cells last 38.5 years on the Ultra and 28.8 on the AC70P, so either one gets retired for reasons that have nothing to do with cell wear, decades after the 5-year warranty stopped mattering. Cycle daily and the same numbers come down to 11 years and 8.2, which is the first point where cost per kilowatt-hour describes something you'll live to see.
Ultra: 4,000 cycles × 3,072Wh = 12,288 kWh over its life, from $1,299 — $0.11 per lifetime kWhAC70P: 3,000 cycles × 864Wh = 2,592 kWh, from $499 — $0.19 per lifetime kWhWarranty is 5 years on each unit
Why it mattersDaily and RV users should let the per-kWh number decide this; anyone powering six weekends a year should ignore it completely and buy on capacity and weight.
The specific dimensions that decide these two units — everything else is a tie.
Runtime: Will It Power Your Gear?
Selected because: Whether 734Wh covers your longest sitting is the only question on this page that changes the answer.
continuous output
Some loads never get as far as a runtime question. Ask the AC70P for more than 1,000W and it declines, however full it happens to be, while the Ultra has 3,600W of runway and 7,200W of surge to start things with. The surge headroom is the same shape on each, exactly double the continuous rating. Only the ceiling differs, and the ceiling is the part that tells you no.
When you do the arithmetic, use 85% of rated capacity rather than the number on the box: 2,611Wh on the Ultra, 734Wh on the AC70P. That's what survives the inverter, and it's the figure your load list has to fit inside. Everything else on this page is downstream of that one subtraction.
Your Life, Your Pick
Selected because: Five of the six load lists here go to the Ultra and the sixth goes to nobody, which is where the capacity gap turns into a yes or a no.
The AC70P clears the 670Wh tailgate with 9% in the tank. Read that as clearing it, singular. There's no second event that afternoon, no extra hour, no cooler someone plugs in at the end. It also handles a 320Wh CPAP night with room to spare, and those two are the whole list of things it finishes.
A remote workday lands at 124% of the small tank, and that kind of shortfall arrives at the end of the day rather than the start. The van day belongs to nobody: 4,685Wh is 179% of even the Ultra, which is the page's way of telling that reader to stop shopping this size class entirely.
Portability & Form Factor
Selected because: 22.5 lb against 72.1 lb is the one place the AC70P wins outright, and for a unit that moves every weekend that can be the whole decision.
weight
One of these you pick up with one hand while the other hand holds a cooler. The other is 3.2 times the weight: feet planted, knees bent, and you think about the stairs before you start. That's not a spec difference, it's a different verb.
So the question is how often it moves, not how strong you are. Bolted into a camper or parked beside the breaker panel, moving twice a year, the Ultra's weight costs you nothing at all. Going trunk to campsite to trunk every Friday, it costs you something every single time, and this is the one place on the page where the AC70P is simply the better object.
Growth Path
Selected because: Neither unit takes an expansion battery, so the size on the box is the size for life.
solar input
There's no port on either of these for a second battery, which makes this the shortest section on the page. Each is a finished object at the size you buy it, and the Ultra's size already covers heavy multi-day loads without help. What's off the menu at both prices is the familiar plan: buy small now, add capacity later.
BLUETTI shoppers should know one thing before they commit. The model that takes the B80 battery and grows to roughly 1,574Wh is the cheaper AC70, not this oneB3; the AC70P spends that flexibility on 96Wh more base capacity and a faster wall chargeB1B2. Pay more here and you get the sealed one. If room to grow is what brought you to the small BLUETTI, you're looking at the wrong model in the line.
Lifetime Value
Selected because: The expensive unit is the cheaper energy, but only if you cycle it often enough to collect.
cost / lifetime kWh
Per year of warranty, the AC70P costs $100 and the Ultra $260. Per kilowatt-hour actually delivered, the ranking flips, because 4,000 cycles of a 3,072Wh pack is 12,288 kWh of energy against 2,592 kWh from 3,000 cycles of 864Wh. Same five years of paper on each, very different amounts of electricity underneath it.
Which number is yours depends on how often you cycle. At six weekends a year the cells outlive the warranty by decades on either unit, so the per-kWh figure is a spreadsheet fact and you should be shopping on capacity and weight instead. Cycle it daily and that same math starts describing years you'll actually be in the room for.
Strengths & trade-offs
EcoFlow DELTA 3 Ultra
Strengths
- +Larger battery capacity
- +Higher AC output
- +Faster solar charging
- +Rated for 4,000 charge cycles — much longer battery lifespan
Trade-offs
- –Substantially more expensive (+$900) than the AC70P.
- –Significantly heavier (+49.6 lbs), making it harder to move.
BLUETTI AC70P
Strengths
- +Costs $900 less
- +Lighter by 49.6 lb
Trade-offs
- –Weaker inverter (-2,600W) limits appliance compatibility.
- –Shorter-lived battery — rated for 3,000 charge cycles vs the DELTA 3 Ultra's 4,000, so it wears out sooner.
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
A weekend costs 2,100Wh, which is 80% of the Ultra and one uneventful drain. The AC70P sits at 286% of the same list, close to three full tanks across two days, so you'd spend the weekend recharging the thing you brought so you wouldn't have to recharge things. The Ultra takes this one without a conversation.
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
DELTA 3 Ultra
1,645Wh of outage takes 63% of the Ultra, so the power comes back with a third of the pack still in hand. The AC70P covers about 45% of that list before it's flat. Call that a scoping exercise rather than a failure: decide which half of the house you're running before the lights go out, not during.
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
DELTA 3 Ultra
Both units sail through a 320Wh night, 12% of the Ultra against 44% of the AC70P, so the decision moves to the two things you notice at 3 a.m. The Ultra gives you eight nights on a charge at a rated 30 dBA. The AC70P gives you two, at 45 dBA, and refills in under two hours of full sun if you've brought a panel.
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
DELTA 3 Ultra
910Wh of work is 35% of the Ultra and 124% of the AC70P, a 176Wh shortfall. That gap doesn't announce itself in the morning. It arrives in the last hour of the day with a document still open. Trim the load list or take the Ultra.
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
670Wh is 91% of what the AC70P holds, so it clears a tailgate and ends with the tank essentially empty. The Ultra does the same list at 26% and is the one to own if the afternoon ever runs long, though it also asks you to move 72.1 lb rather than 22.5. One planned afternoon, the small one is enough. Anything open-ended, bring the big one.
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
Nobody wins this one. A full van day runs 4,685Wh, which is 179% of the Ultra and 638% of the AC70P, and no expansion battery exists for either unit to close that distance. Daily van power at this level means a fixed house bank sized past 4,685Wh, charging off the alternator and shore power. Neither box here is a step toward 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: DELTA 3 Ultra runs 12.7h vs 3.6h.
$1,399 list · direct from EcoFlow
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 0–174.1hComfort & Convenience
Makes off-grid life actually enjoyablescale 0–34.8hHigh-Draw Appliances
These reveal the real limitsscale 0–2.6h¹ 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
August 2, 2026
Verdict: the DELTA 3 Ultra, on Power Score margin
Take the DELTA 3 Ultra. It starts anything up to 3,600W where the AC70P stops dead at 1,000W, and it holds enough that weekend camping, an eight-hour blackout, a remote workday and a tailgate all finish on a single charge. The AC70P finishes two of those, and one of them, the tailgate, ends with 91% of its tank gone. It's also the cheaper energy twice over: $0.42 a watt-hour on the shelf against $0.58, and $0.11 per lifetime kilowatt-hour against $0.19. Confidence sits at 7 rather than 9 because the price gap is real money and 72.1 lb is real weight. If your biggest single sitting honestly lands under 734Wh, and somebody has to carry this thing to wherever it works, buy the AC70P and let the Ultra's spare 2,208Wh be somebody else's problem.
Editor-assigned confidence, based on cited owner research and spec analysis.
List prices as of August 2, 2026. The links below open EcoFlow's and BLUETTI's current prices.
$1,399.00 · direct from EcoFlow
Last checked 3 days ago. Prices move — check before you buy.
or check the AC70P price$499.00 list
Written by Ian Schneider, Solar & Off-Grid Tester · Station Arena Test Desk · Updated August 2, 2026
Measured Data
Benchmark scores and the full spec record, side by side.
Benchmark scores
Not rated for both units (minimum threshold unmet): RV Living, Home Backup, CPAP, Food Truck, Apartment Balcony, Camping.
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 Ultra rates 4.6/5 (79th percentile of 25 Large-class units), and AC70P rates 4.5/5 (68th percentile of 20 Compact-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.
Where It Lives Decides Whether 72.1 lb Matters
The Ultra is 49.6 lb heavier than the AC70P, and this is the strongest argument the small unit has. Work out where it's going to live. Beside a breaker panel or bolted into a camper, moving twice a year, that weight costs you nothing. In and out of a trunk every Friday, it's a tax you pay on every trip, and the AC70P is the one you carry in the hand that isn't holding the cooler.
45 dBA Only Matters Where It Sleeps
The AC70P is rated 45 dBA under load, the Ultra 30. In a garage or a truck bed that gap is trivia. Eighteen inches from a pillow it's the entire decision, which is why the quiet one takes the CPAP scenario even though that job uses 12% of its capacity and 44% of the AC70P's.
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 AC70P 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: No Difference
Both units carry the same 5-year warranty, so coverage isn't a tiebreaker here. Worth saying because the per-dollar framing can suggest otherwise: the AC70P works out at 10 years of cover per $1,000 spent against the DELTA 3 Ultra's 3.6, but that spread is the price gap, not the terms.
4,000 vs 3,000 Cycles Understates It
The cycle counts look close until you remember that a cycle is one full tank, and these tanks aren't the same size. 4,000 cycles of 3,072Wh is 12,288 kWh over the Ultra's life. 3,000 cycles of 864Wh is 2,592 kWh. That ratio, not the cycle count, is what makes the expensive unit the cheaper energy, and you only collect it by actually cycling the thing.
Full record above — the Test Desk pick is the DELTA 3 Ultra.
Check DELTA 3 Ultra price →or check the AC70P 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 AC70P is cheaper to buy, but the DELTA 3 Ultra is cheaper to own. At $0.11/kWh over its lifetime vs $0.19/kWh, the DELTA 3 Ultra's higher cycle life and capacity make each dollar go further over the years.
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 and chat, and the outcomes split hard. Plenty of claims end with a prepaid label and a replacement, no argument. Others turn into long waits, and some come back refurbished against a claim on a new unit. Buying through Costco or Amazon gives you a second return path that costs nothing to hold.
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 very top of the range, the DELTA Pro Ultra platform stacks batteries and inverters into whole-home backup — a flagship path, not a line-wide feature.
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 category, email-first and lagged by China timezones. Some claims get handled quickly and efficiently. Others turn into weeks of troubleshooting, or an offer of a discount on a new unit in place of a repair on the one you own. Buying direct from BLUETTI rather than through a marketplace tends to produce better 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 the lineup, though rated cycle life spans 2,500 (EB3A) to 6,000 (Elite units) — 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
Read the support gap against the price tag. On a $499 unit a bad claim is an annoyance you absorb; on a $1,299 one it's worth choosing where you buy before you click. Coverage isn't the difference, since each carries 5 years. The difference is how much of your life it takes to use it.
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.
Generous port selection supports complex multi-device setups.
AC70P
FIXED CAPACITYFixed at 864Wh, 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
Neither expands, and that's no knock on either — each is a complete unit at a fixed size. Buy the capacity that covers your needs now (the DELTA 3 Ultra gives you the larger ceiling); you can't add to either later.
What Owners Report
Patterns from published owner reports and long-term reviews — every claim cited to its source below.
EcoFlow DELTA 3 Ultra
The file on this unit is weeks of reviewer testing, not years of ownership, so read it as provisionalA5A7A9. Inside that limit, two findings keep coming back. The fans stay out of the way: reviewers call it much quieter than older EcoFlow models even with the inverter at maximum output, and say the noise never becomes distractingA1A2. And the handoff from wall power is clean. Testers compared it to an APC UPS kicking in and saw no dips or shutdowns when they pulled the plugA5A6, which is what a 10ms rating is supposed to feel like.
Two smaller things are worth knowing before you spend this much. One reviewer found the unit drops its 30A port first when the load goes past the limitA3, which matters if that port is the reason you're buying. Another had to cup a hand over the display to read it in direct sunA11. On the other side, the casing, the AC cable and the sliding covers over the input ports get called substantial rather than cheap, repeatedlyA9A15. Under sustained real work, one reviewer pulling 300W to 600W on a single AC output measured a little over 4.5 hours, and got through an eight-hour remote workday with 40% still showingA7A8.
“Even when you're pushing it hard, the DELTA 3 Ultra Plus runs much quieter than older EcoFlow models, like the DELTA 2 Max.”
Sources
thesolarlab.com · postperspective.com · appleinsider.com · digitaltrends.com · popsci.com
BLUETTI AC70P
There's less to go on here, and what exists comes from spec guides and reviews rather than anyone who has lived with one for a yearB1B2. It is at least specific: 864Wh of LiFePO4, about 96Wh more than the cheaper AC70B1; 1,000W continuous with 2,000W of surge, 12V and 24V car charging, and up to 500W of solarB4; and a wall charge that reaches 80% from flat in roughly 0.8 hoursB2, which is the kind of turnaround that makes a small pack feel bigger than it is.
The file's most useful entry is a correction. This is the sealed model, and it's the cheaper AC70 that accepts BLUETTI's B80 battery to reach roughly 1,574WhB3. If you came here planning to add capacity down the road, the AC70 is the model you actually wanted.
“Holds 864Wh — about 96Wh more than the AC70 — on safe, stable LiFePO4 chemistry built for thousands of charge cycles.”
Sources
bluettipower.com · bestgeneratorsolar.com · madetoexplore.ca · truegear.com.au
Sources & Research Notes
Every owner claim in this report is traceable to a published source. The bracketed references above resolve here.
Recurring owner themes
- Reviewers consistently praise the quiet fan operation of the Ultra-tier unit compared to older EcoFlow models, though this is described in professional test conditions rather than long-term ownership. [DELTA 3 Ultra · 2 entries]
- UPS/switchover performance is repeatedly called seamless with no observed dips or shutdowns during power interruption tests. [DELTA 3 Ultra · 3 entries]
- The unit's substantial 74 lb weight is flagged across multiple reviews as a portability drawback, mitigated somewhat by wheels and handle design. [DELTA 3 Ultra · 2 entries]
- Build quality/durability (casing, cable, port covers) is repeatedly highlighted as premium and well-engineered. [DELTA 3 Ultra · 2 entries]
- AC70P's real advantages are more base capacity and faster wall charging; crucially it is sealed while the cheaper AC70 is the expandable model. [AC70P · 3 entries]
- A1
“Even when you're pushing it hard, the DELTA 3 Ultra Plus runs much quieter than older EcoFlow models, like the DELTA 2 Max.”
thesolarlab.com — EcoFlow DELTA 3 Ultra Plus Review: The Ultimate DELTA? · 2025-09/10 (approx) · [positive]
- A2
“Even when you're pushing the inverter to its maximum output, the fans never become annoying or distracting.”
thesolarlab.com — EcoFlow DELTA 3 Ultra Plus Review: The Ultimate DELTA? · 2025-09/10 (approx) · [positive]
- A3
“One weird thing we noticed was the fact that the unit always seems to shut down the 30A port first when you overload the unit.”
thesolarlab.com — EcoFlow DELTA 3 Ultra Plus Review: The Ultimate DELTA? · 2025-09/10 (approx) · [mixed]
- A5
“Over my career I have become accustomed to APC batteries immediately switching on when there is a power hit or power shut-off, and the EcoFlow Delta 3 Ultra Plus works in the exact same way.”
postperspective.com — Review: EcoFlow Delta 3 Ultra Plus Portable Power Station · 2026-04 · [positive]
- A6
“I didn't experience any shut-offs or dips when I unplugged the EcoFlow from the wall.”
postperspective.com — Review: EcoFlow Delta 3 Ultra Plus Portable Power Station · 2026-04 · [positive]
- A7
“Using Maxon's Cinebench 2026 GPU benchmark, I was pulling between 300W and 600W on one of the AC outputs... the EcoFlow Delta 3 Ultra Plus would last a little over 4.5 hours.”
postperspective.com — Review: EcoFlow Delta 3 Ultra Plus Portable Power Station · 2026-04 · [positive]
- A8
“I was able to work remotely for an eight-hour day with 40% power left, which included running my laptop, desktop workstation and monitors.”
postperspective.com — Review: EcoFlow Delta 3 Ultra Plus Portable Power Station · 2026-04 · [positive]
- A9
“It does not feel cheap or fragile. Everything from the outer shell case to the plastic buttons and the AC cable feels substantial and durable enough to withstand day-to-day wear and tear.”
appleinsider.com — EcoFlow Delta 3 Ultra Plus review: Premium, but solid power · 2025-11-16 · [positive]
- A11
“But, while facing the sun, I had to employ the classic "cup hands cover" maneuver to get a clear look at the screen status.”
appleinsider.com — EcoFlow Delta 3 Ultra Plus review: Premium, but solid power · 2025-11-16 · [negative]
- A15
“I really love how the rear panel doors for the input ports slide into protective slots when in use.”
popsci.com — EcoFlow DELTA 3 portable power station series first impressions · 2025-09-29 · [positive]
- B1
“Holds 864Wh — about 96Wh more than the AC70 — on safe, stable LiFePO4 chemistry built for thousands of charge cycles.”
bluettipower.com / bestgeneratorsolar.com — AC70P buyer's guide · 2026 · [positive]
- B2
“Recharges faster from the wall — supports a higher AC input and reaches 0 to 80% in roughly 0.8 hours, acting as an efficient fast charger when you're in a hurry.”
bluettipower.com / madetoexplore.ca — AC70P review · 2026 · [positive]
- B3
“The AC70P does NOT support battery expansion — it is sealed at 864Wh. By contrast, the cheaper AC70 CAN expand to roughly 1,574Wh by adding BLUETTI's B80 expansion battery.”
truegear.com.au / bluettipower.com — AC70 vs AC70P comparison · 2026 · [mixed]
- B4
“1,000W continuous / 2,000W surge, car charging (12V/24V), and solar up to 500W — the same as the AC70.”
bluettipower.com — AC70P specifications · 2026 · [positive]
Research compiled August 2, 2026.
Who Should Buy Which
Buy the DELTA 3 Ultra if you…
- →You want to sit out an eight-hour outage without deciding which appliances matter. That list is 63% of the Ultra, so the lights come back with a third of the pack untouched.
- →You car-camp with the unit parked by the tailgate all weekend, where the whole weekend is one drain instead of three.
- →You work off-grid on a desktop and monitors: one reviewer got through an eight-hour day and still had 40% leftA8.
- →Something on your list pulls more than 1,000W. That's a wall on the AC70P and open road on the Ultra.
- →You run a CPAP and want margin and quiet: eight nights per charge, at a rated 30 dBA.
Buy the AC70P if you…
- →The job is one appliance for one night. A CPAP takes 320Wh, 44% of what this unit really holds, and 22.5 lb sets down beside a bed without ceremony.
- →Tailgates and day trips landing near 670Wh, where the event ends before the battery does.
- →It has to move constantly and one person has to lift it. That's the whole argument for the small unit, and it's a good one.
- →Budget is the binding constraint at $499, and a wall charge back to 80% in roughly 0.8 hours means you can turn it around between usesB2.
If neither fits
If your day looks like the van-life list at 4,685Wh, close this tab cheerfully. Neither of these covers it, and you can't stack your way there, because no expansion battery exists for either model. What you want is a fixed lithium house bank sized past that number, charging off the alternator and shore power, or a proper home backup system. This page isn't your page.
The Bottom Line
Take the DELTA 3 Ultra. The reason is a line rather than a feature: 734Wh is everything the AC70P has to give, and four of the six load lists on this page walk straight past it. Camping. A blackout. A workday. A van day. The Ultra swallows the first three at 80%, 63% and 35% of its pack, and it costs less per kilowatt-hour delivered over its life than the unit that looks cheaper on the shelf.
Buy the AC70P when the job really is small and singular, a CPAP night or a tailgate, because then you're paying for the part you use and carrying 22.5 lb instead of 72.1. What you can't do is buy it as a first step. There's no expansion battery for either unit, so the only upgrade path from an AC70P that turned out too small is buying a second power station. Decide the ceiling once, and decide it now.
Frequently Asked Questions
Answers drawn from the spec record and cited owner research.
Is the EcoFlow DELTA 3 Ultra worth $800 more than the BLUETTI AC70P?
It is if any single sitting on your load list passes 734Wh, which is what the AC70P actually delivers out of its rated 864Wh. Above that line the small unit needs a mid-job recharge and the big one doesn't, and there's no add-on battery for either to close the gap later. Below that line you're buying headroom you'll never reach, and the AC70P is the better purchase.
Can the BLUETTI AC70P get through an 8-hour blackout?
Not all of it. The modelled outage list runs 1,645Wh and the AC70P holds 734Wh you can spend, so it covers roughly 45% before it's flat, against 63% of the DELTA 3 Ultra's pack for the same list. Pick now which half of that list you're willing to lose, because you'll be picking either way, and doing it by flashlight is worse.
Does the EcoFlow DELTA 3 Ultra take an expansion battery?
No. It's fixed at 3,072Wh, and the AC70P is sealed at 864Wh, so whatever's on the box is what you own for the life of the unit. That's not a flaw in either one, since each is a complete system at its size, but it does mean buying the ceiling you need up front. If expandability at the small end is what you're after, BLUETTI's cheaper AC70 is the model that accepts the B80 battery to about 1,574Wh.
Which one is quieter for a bedroom or a CPAP?
The DELTA 3 Ultra, rated 30 dBA against the AC70P's 45, and reviewers describe its fans as unobtrusive even with the inverter pushed hard. Capacity says the same thing from the other direction: a 320Wh night is 12% of the Ultra, so it runs eight nights per charge where the AC70P gets two. The AC70P still works next to a bed if you own a panel, since 500W refills it in under two hours of full sun.
How long does each one take to recharge?
From solar, 3,072Wh ÷ 800W puts the Ultra at just under four hours at full rated input, and 864Wh ÷ 500W puts the AC70P at under two. Treat both as best case, because panels don't hold their rating all day. From the wall the AC70P reaches 80% in roughly 0.8 hours, which is the most underrated thing about it if you're turning it around between short trips.
Brand matchup
EcoFlow vs BLUETTI: measured across every matchup →Where to buy
EcoFlow DELTA 3 UltraPick
$1,399.00
$1,399.00 · direct from EcoFlow
Last checked 3 days ago. Prices move — check before you buy.
BLUETTI AC70P
$499.00
$499.00 · direct from BLUETTI
Last checked 3 days ago. Prices move — check before you buy.
Prices may vary by retailer and are subject to change.