Head-to-head test
EcoFlow DELTA Pro Ultra X vs BLUETTI AC300 + 4×B300
The battery is identical on both sides, down to the rated cycle count, so this was never a capacity decision: it is whether you need four times the inverter and four times the solar ceiling, and $2,403 is what they cost.
Full profiles: EcoFlow DELTA Pro Ultra X → · BLUETTI AC300 + 4×B300 →
Written by Gunner GustafsonUpdated
Whole-Home Backup Tester, Station Arena Test Desk
Spec deltas
Both of these stack 12,288Wh of LFP and both are rated for 3,500 cycles, which means each one delivers 43,008 kWh before it is done. The batteries cancel out exactly. What $2,403 separates is everything around the battery: 12,000W of continuous output against 3,000W, a 45,000W published peak against 6,000W, and a solar input ceiling of 10,000W against 2,400W.
Take the DELTA Pro Ultra X if any of that is load-bearing for you. Its 12kW at 120/240V is enough to carry every circuit in a house including a 5-ton air conditionerA1, and that input ceiling refills the entire bank in about an hour of full rated sun where the AC300 stack needs roughly five (12,288Wh divided by 10,000W and by 2,400W). It is also the live flagship of a platform that runs to 184.32kWhA2, with five years of coverage behind it.
The BLUETTI is not a bad buy and its case is a short one: the same stored energy for $5,596. Its inverter runs a fridge, a freezer, a furnace fan and the lights all at once without complaint, and if that is the list, the EcoFlow's extra output is headroom you will never reach. The reason to hesitate is not capability. It is that BLUETTI's support has told an owner the AC300 is discontinued and not worth repairing because the parts are goneB9B10, and the head unit is the one part of this purchase you cannot swap out later.
What the Numbers Reveal
Each conclusion stated first — the numbers behind it on one line, the full analysis below.
continuous output
That reframes the whole decision as a plumbing question rather than a storage one, and plumbing is checkable in advance. Add up the circuits you actually intend to hand over and count the panels you can actually mount. If the answers stay under 3,000W and under 2,400W, the EcoFlow's four-times advantage is unreachable and you are paying $2,403 for a ceiling you cannot touch. If either answer goes over, the AC300 stack cannot do the job at any discount.
Both units hold 12,288Wh and both are rated for 3,500 cycles, so each totals 43,008 lifetime kWhContinuous output is 12,000W against 3,000W; published peak is 45,000W against 6,000WSolar input ceiling is 10,000W against 2,400W
Why it mattersAnyone tying into a 240V panel or feeding a ground-mount array should buy the EcoFlow; anyone backing up a chosen handful of 120V circuits should save the money.
Left armed, that is 1,440Wh a day (60W times 24 hours), which would empty a full 12,288Wh bank in about eight and a half days with nothing whatsoever plugged in. On a grid connection that is a small standing bill you will never notice. Off grid it is a load you have to generate before you generate anything useful, and it is competing with a 2,400W input ceiling rather than a 10,000W one. No comparable measurement exists for the DELTA Pro Ultra X, so this is a cost to plan around rather than a contest anyone wonA0.
A reviewer measured the AC300's idle draw at close to 60W with AC output on and nothing plugged inB2Four hours idle consumed about 8% of the batteryB3That 8% reconciles with a single-B300 AC300 at 3,072Wh (12,288 divided by 4), not with this four-module stack: 60W for four hours is 240Wh, which is 8% of 3,072Wh and about 2% of 12,288Wh
Why it mattersOff-grid buyers choosing the AC300 stack should either budget 1,440Wh a day for standby or switch the inverter off between uses; grid-tied standby buyers can ignore it.
cost / lifetime kWh
Four healthy B300s with nothing to run them through is worth scrap value, so the $0.13 is only as good as the head unit. That makes the checkout page part of the engineering: BLUETTI's terms are two years bought through a reseller and up to five bought direct and registered, which decides whether a year-four failure is a warranty claim or a $5,596 write-off. The EcoFlow has no clean story here either, since it offers no parts or service out of warranty, but it is a current product with five years on the clock rather than a discontinued one.
Identical lifetime energy on both sides means $0.13 against $0.19 per lifetime kWh is the $2,403 price gap restated, nothing moreAt daily cycling both stacks take about 9.6 years to reach 3,500 cyclesAn owner's AC300 head unit threw console errors and went deadB9, and BLUETTI support replied that the model is discontinued, parts are unavailable, and repair is not recommendedB10
Why it mattersIf the $2,403 saving is what brings you to the BLUETTI, buy it direct and register it, or treat the saving as the price of a shorter service life.
The specific dimensions that decide these two units — everything else is a tie.
What the Specs Don't Tell You
Selected because: The flagged items are where these two stop being the same machine: 12,000W continuous against 3,000W, a 45,000W published peak against 6,000W, and a 68.5 lb weight difference that only bills you once.
The output gap is the only flagged item that changes what you can plug in. A 6,000W peak is double the AC300 stack's continuous rating, and doubling is plenty to absorb the startup spike of any single appliance in this page's scenario set, where the heaviest peak is 400W. So the thing the AC300 cannot do is not starting a motor. It is running your list all at once: central air, a well pump and a 240V dryer are past 3,000W by a wide margin, and no surge ratio rescues that.
The weight line reads like a portability warning and it is not one. Both of these are freight, 298.7 lb and 367.2 lb, and both are rated stationary. You pay the 68.5 lb difference exactly once, on the afternoon you decide which corner of the garage it lives in, and never again. Spend that decision on how far it sits from the breaker panel instead.
Lifetime Value
Selected because: Identical capacity and identical rated cycles mean both stacks deliver 43,008 lifetime kWh, so every cent of the cost-per-kWh difference is the $2,403 price gap and nothing else.
cost / lifetime kWh
Both stacks deliver 43,008 kWh over their rated lives, 12,288Wh times 3,500 cycles, identical on both sides. That makes this the rare cost-per-kWh comparison that is completely honest and completely boring: thirteen cents against nineteen is the price tag in smaller units, not a discovery about the cells. Nothing here is an efficiency argument, because there is no efficiency difference to argue about.
The one running cost the spec sheet misses sits on the BLUETTI side, and it is the roughly 60W the AC300 draws doing nothing at all with its inverter switched onB2B3. That aside, the money question reduces to something you can answer in a sentence: is $2,403 of output and input worth $2,403 to you? If your list fits inside 3,000W, no. If it does not, the cheaper stack cannot do the job at any price.
Brand Trust
Selected because: On hardware this size the warranty and the parts supply are the real running costs: five years on the EcoFlow, and on the BLUETTI two years through a reseller or up to five bought direct and registered.
The most alarming sentence on this page is not in a spec table. An owner's AC300 head unit threw console errors and then died outright, and BLUETTI's support answered that the model is discontinued, the parts are not there, and repair is not worth the shippingB9B10. The four batteries in that stack were fine. That is the failure mode of a modular system, and it is the one the $5,596 does not insure you against.
EcoFlow gets no halo here, because it offers no parts and no service once the warranty lapses either. The difference is timing rather than virtue: the DELTA Pro Ultra X is the current flagship of a platform EcoFlow is still building on, and it carries five years. Whichever you choose, buy direct and register it. On the BLUETTI that is the gap between two years of coverage and up to five, and direct is also the channel where its email-first support behaves best.
Growth Path
Selected because: Both add batteries, but only one can feed a growing bank from a 10,000W array. The other tops out at 2,400W of solar input however many modules you bolt on.
solar input
Both add batteries; only one adds a power plant. The DELTA Pro Ultra X's platform runs to 61.44kWh on a single inverter and 184.32kWh across threeA2, and it will swallow 10,000W of solar to keep that fed. The AC300's input ceiling is 2,400W, about five hours of full rated sun to refill the 12,288Wh it already carries (12,288 divided by 2,400), and bolting on more batteries does not raise it by a watt.
That asymmetry decides the off-grid case and nothing else. If this bank sits behind a grid connection and solar is a way to shave the bill, the input ceiling never binds and you are paying for a number. If the bank is your utility, the unit that can absorb a big array inside a short winter afternoon is the one that keeps you out of rationing.
Strengths & trade-offs
EcoFlow DELTA Pro Ultra X
Strengths
- +Lighter by 68.5 lb
- +Higher AC output
- +Longer warranty
- +Faster solar charging
Trade-offs
- –Substantially more expensive (+$2,403) than the AC300 + 4×B300.
- –Very heavy unit that may be difficult for one person to lift.
BLUETTI AC300 + 4×B300
Strengths
- +Costs $2,403 less
Trade-offs
- –Significantly heavier (+68.5 lbs), making it harder to move.
- –Weaker inverter (-9,000W) 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
Neither unit
Scoring these two at a campsite is a category error: neither travels — the DELTA Pro Ultra X is 298.7 lbs and the AC300 + 4×B300 367.2 lbs, and at those weights they roll off a truck bed if they go anywhere at all. The 2,100Wh here is trivial for either — it's the going that doesn't happen. If you need power away from the building, you're shopping the wrong class.
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
Either unit
Eight hours of the usual outage list is 1,645Wh, roughly a sixth of what either stack holds usable, so both are wildly over-provisioned for the event people buy them for. What separates them is how much of the house you get to hand over while the grid is down. One backs a panel; the other backs the circuits you chose in advance. Both list a UPS mode at a rated switchover class, and a rating is not a measurement.
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 asks about 40W for eight hours, so 320Wh, roughly 3% of what either unit holds usable. Buying 12,288Wh to run a CPAP works, and it overpays by thousands. If this genuinely is the load, the only spec worth arguing about is the fan eighteen inches from your head, and only one of these publishes a noise figure at all. Treat that published 30dB as a manufacturer floor for a quiet mode rather than something measured in a bedroom.
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
Either unit
A laptop, a monitor and a router for a day comes to 910Wh. Either stack covers eleven of those days on a single charge (10,445Wh usable divided by 910Wh), which tells you the workday is not the reason to be on this page. USB-C tops out at 100W on both, so the desk itself feels identical whichever one is under it.
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
Neither unit
Neither, and the energy has nothing to do with it. 670Wh with a 400W peak is a rounding error against either bank. It is that the lighter of the two weighs 298.7 lb, the heavier 367.2 lb, and both are rated stationary, so you would be renting a liftgate to bring a battery to a parking lot. Buy a portable you can carry one-handed for this and leave the stack wired in at home.
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
Either unit
Both cover a full 4,685Wh day and land at 45% used, so on paper this is the scenario these are sized for. Off paper you are adding 298.7 lb or 367.2 lb of battery to a vehicle, and the input ceilings that separate them are hard to reach from a roof, since nobody fits 2,400W of panel up there let alone 10,000W. The DELTA Pro Ultra X's bigger ceiling pays off if you recharge from a driveway array between trips. If it is genuinely a van, the energy question is settled and payload is the whole conversation.
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
Dead heat — both run this 205W load for roughly 51h. Pick on price, weight, or ports.
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
September 13, 2026
Verdict: the DELTA Pro Ultra X, on Power Score margin
Take the DELTA Pro Ultra X. Both stacks hold 12,288Wh at 3,500 rated cycles, so both deliver 43,008 kWh over their lives and the $2,403 gap buys no stored energy at all. It buys flow: four times the continuous output, and an input ceiling that refills the whole bank in about an hour of full rated sun instead of roughly five (12,288Wh divided by 10,000W and by 2,400W). Two things push that past a close call. The EcoFlow is the current flagship of a platform that scales to 184.32kWh across three invertersA2 and carries five years of coverage, while the AC300 is a 2021 designB0 whose head unit has already died in the field, with BLUETTI support declining to repair a discontinued model for lack of partsB9B10. If your entire load list fits inside 3,000W and you buy the BLUETTI direct and register it, which is the difference between two years of coverage and up to five, the saving is real and defensible. Everyone else should spend it.
Editor-assigned confidence, based on cited owner research and spec analysis.
List prices as of September 13, 2026. The links below open EcoFlow's and BLUETTI's current prices.
$7,999.00 · direct from EcoFlow
Last checked 16 days ago. Prices move — check before you buy.
or check the AC300 + 4×B300 price$5,596.00 list
Written by Gunner Gustafson, Whole-Home Backup Tester · Station Arena Test Desk · Updated September 13, 2026
Black Friday · 38 days out
Prices to beat:DELTA Pro Ultra X $7,999AC300 + 4×B300 $5,596
We have never seen either discounted, so any real cut would be a first.
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 Pro Ultra X rates 4.3/5 (61st percentile of 29 Whole-Home / Off-Grid-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: a decision you make once
Neither of these moves again after the day it lands. The DELTA Pro Ultra X is 298.7 lb, the AC300 stack is 367.2 lb, both are rated stationary, and both arrive as an inverter plus separate battery modules rather than one monolith, so no single lift is the full figure. The 68.5 lb difference bills you exactly once, on the afternoon you pick which corner of the garage or basement it lives in. Spend that decision on how far it sits from the breaker panel instead.
Surge headroom: read the watts, not the ratio
The DELTA Pro Ultra X holds 12,000W continuous with a 45,000W published peak, which leaves 33,000W of headroom above its own rating. The AC300 stack holds 3,000W with a 6,000W peak, so 3,000W of headroom. That is a real advantage to the EcoFlow, but not the one a ratio implies: doubling is already enough for an appliance startup spike, and the heaviest peak anywhere in this page's scenario set is 400W. The AC300's limit is not flinching when a compressor kicks in. It is the 3,000W ceiling on everything running at once, and that is where central air and a well pump land on the wrong side.
Switchover: two ratings, one carry
The ≤10ms and ≤20ms figures are ceilings the manufacturers published rather than stopwatch results, and both sit inside what routers and most desktop supplies ride through. The rating is the small half of a UPS decision. The big half is how much the inverter can carry the instant it takes over, and that is 12,000W against 3,000W. A transfer quick enough to save your unsaved document is no help if the thing it transferred to cannot also run the furnace.
Warranty: BLUETTI's number depends on where you buy
The DELTA Pro Ultra X carries five years. BLUETTI's term is conditional rather than fixed: two years bought through a reseller, up to five bought direct with the unit registered. So this comparison is settled at checkout rather than on the spec sheet, and it points the same way as everything else about BLUETTI ownership, since direct is also the channel where its support works best. Worth remembering what a warranty on hardware this size is really insuring: the inverter head, not the cells.
Only one of these publishes a noise figure
The DELTA Pro Ultra X lists 30dB and the AC300 stack lists nothing. That is not evidence the BLUETTI is louder, and the 30dB is not a measurement either. It is a manufacturer floor, the sort of figure that describes a quiet mode at low load, and a 12,000W inverter working hard is not sitting at its floor. The real difference is that one of these can be held to a claim and the other can only be listened to.
Full record above — the Test Desk pick is the DELTA Pro Ultra X.
Check DELTA Pro Ultra X price →or check the AC300 + 4×B300 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 AC300 + 4×B300 wins on both sticker price and long-term value. At $0.13/kWh over its lifetime, it's meaningfully cheaper to own. Clear value winner. One thing to know reading the table: both carry the same 3,500-cycle rating, so the lifetime rows are sticker price and capacity in disguise — the wear horizon is identical and decides nothing here.
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 phone, email and chat, with a polarized record: prepaid-label replacements and quick turnarounds at one end, long waits and refurbished units against new-unit claims at the other. The practical hedge is the retailer rather than the brand, since buying through Costco or Amazon puts a return policy behind the warranty.
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
Two things to file away. EcoFlow tested subscription paywalls for advanced app features in early 2025 and paused the plan after the backlash, so treat app functionality as something that can move under you. And out of warranty, EcoFlow offers no parts and no service at all, which means on a $7,999 install the five-year term is the entire repair plan.
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
Email-first with China-timezone delays, and the most inconsistent record in the category: efficient for some, weeks of troubleshooting runaround for others, occasionally a discount on a new unit offered instead of a repair. Claims on third-party purchases are the worst version of it. Buying direct is the single biggest variable you control.
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
Some of the best capacity per dollar available anywhere, full LFP standardization across the range, and the widest product diversity in the category, from sodium-ion cold-weather units to dual solar-plus-alternator vehicle hubs. The AC300 stack is that strength in its purest form: 12,288Wh for $5,596.
Worth knowing
BLUETTI has no spare-parts policy for some discontinued models, which is the single biggest risk in owning a mature BLUETTI. The AC300 is a mature BLUETTI. That is not a knock on the cells; it is a statement about the box they plug into.
Analyst note
Both brands walk away from hardware once the warranty is up. EcoFlow says so out loud: no parts, no service, out of warranty. BLUETTI's version is quieter and arrives later, as a discontinued model with nothing left on the shelf to fix it with. So the brand question is not which company repairs your unit in year seven, because neither of them does. It is which product is still current when year three goes wrong, and which channel you bought it through.
Growth path
DELTA Pro Ultra X
EXPANDABLESupports EcoFlow 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 10,000W 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 EcoFlow-specific. You're investing in the EcoFlow ecosystem.
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
Both expand, but the DELTA Pro Ultra X's higher solar ceiling (10,000W vs 2,400W) gives it the stronger off-grid growth path — more panels can feed a bigger bank as it grows.
What Owners Report
Patterns from published owner reports and long-term reviews — every claim cited to its source below.
EcoFlow DELTA Pro Ultra X
There is no long-term owner record for the DELTA Pro Ultra X yetA0. What exists is EcoFlow's own material plus launch-window reviews: 12kW continuous at 120/240V, enough for every circuit including a 5-ton AC, scaling to 12-36kW with surge handling to 45kW via Adaptive StartA1; a base 12.288kWh built as two 6,144Wh modules and expandable to 61.44kWh on one inverter or 184.32kWh across threeA2; EV-grade full-tab LFP cells with multi-layer safety and 24/7 BMS oversightA3; and a quick-connect install said to cut installation time and cost by up to 80% and to be ready in about seven daysA4. Read the install figure as the manufacturer's claim, because that is whose it isA0.
The absence costs you specific things. Nobody has reported back on how the fans behave after an hour at heavy load, on what it draws sitting armed and idle, or on what a warranty claim on a $7,999 system actually feels like to makeA0. The 30dB on the spec sheet is a best-case floor of the kind manufacturers publish for a quiet mode, not a figure anyone recorded in a room.
“Base config delivers 12kW continuous at 120/240V — enough to power every circuit including a 5-ton AC — scaling to 12-36kW with surge handling to 45kW via Adaptive Start.”
Sources
ecoflow.com · outboundpower.com · bobvila.com · thesolarlab.com
BLUETTI AC300 + 4×B300
The AC300 has years of field record and it is mixed in a genuinely useful way. Build quality lands well, with one reviewer immediately impressed by the unit's quality, finish and clever designB1. The fan gets forgiving treatment from everyone who has listened to it: audible rather than silent but easy to forget for the size of the thingB5, with one AC300 owner describing no detectable motor or bearing noise at all, only air movementB6. Recharging from near empty to full in a little over an hour is rated very goodB4, and a Forbes test kept a fridge alive for an average of 31 hours per chargeB11. That test ran on an AC300 with a single B300, 3,072Wh or a quarter of this stack, so four modules behind the same inverter puts a fridge nearer five days (31 hours times 4).
The two complaints that matter are both about the head unit rather than the batteries. Idle draw with AC switched on and nothing connected measured close to 60W, high enough that four idle hours ate about 8% of the batteryB2B3, and that 8% was on the single-B300 configuration, so on this stack the same 60W reads nearer 2% in four hours while costing the identical watts. The app is the other soft spot: basic enough to leave you wanting moreB7, with at least one owner stuck on a version that loads forever while the unit itself reports ConnectedB8. And the ending is on the record. A head unit dead about five years after launch, and support declining to supply parts for a discontinued modelB9B10. Two of those forum threads we could only corroborate secondhand, so weight them accordinglyB0.
“I was immediately impressed with the unit's quality, finish, and clever design.”
Sources
reviewed.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
- Whole-home 12kW output, massive scalability (to 184kWh), EV-grade LFP, 10kW solar, and fast install are the standout features. [DELTA Pro Ultra X · 3 entries]
- Idle power draw is noticeably higher than expected and drains meaningful battery even with no connected load. [AC300 + 4×B300 · 2 entries]
- Reviewers and owners consistently describe the AC300's fan as audible under load but notably quiet for its size and class. [AC300 + 4×B300 · 2 entries]
- The companion app is described as basic/limited, and some owners report Bluetooth or app-pairing problems connecting to the AC300+B300. [AC300 + 4×B300 · 2 entries]
- After several years of service, some head units fail outright, and once discontinued Bluetti has no repair parts and does not recommend repairing out-of-warranty units. [AC300 + 4×B300 · 2 entries]
- A1
“Base config delivers 12kW continuous at 120/240V — enough to power every circuit including a 5-ton AC — scaling to 12-36kW with surge handling to 45kW via Adaptive Start.”
ecoflow.com / outboundpower.com — DELTA Pro Ultra X review · 2026 · [positive]
- A2
“Base 12.288kWh of LFP storage (6,144Wh x 2), expandable to 61.44kWh with one inverter and up to 184.32kWh with three inverters and thirty batteries.”
ecoflow.com / outboundpower.com — DELTA Pro Ultra X · 2026 · [positive]
- A3
“EV-grade full-tab LFP cells with a multi-layer safety architecture and 24/7 BMS oversight; solar charging up to 10kW.”
ecoflow.com / bobvila.com — DELTA Pro Ultra X review · 2026 · [positive]
- A4
“A quick-connect design cuts installation time and cost by up to 80%, ready in about 7 days; a CES 2026 Innovation Award Honoree at a $7,999 base price.”
ecoflow.com / thesolarlab.com — DELTA Pro Ultra X review · 2026 · [positive]
- B1
“I was immediately impressed with the unit's quality, finish, and clever design.”
Clean Energy Reviews Forum — "Bluetti Power Station Review (AC300) Off-grid Backup" (user Svarky) · 2023-07 · [positive]
- B2
“When the AC output is switched on, the idle power draw (with no load) appears to be close to 60W, which is high.”
Clean Energy Reviews Forum — "Bluetti Power Station Review (AC300) Off-grid Backup" (user Svarky) · 2023-10 · [negative]
- B3
“When left on for 4 hours with no load, it consumed around 8% of the battery, which was rather surprising.”
Clean Energy Reviews Forum — "Bluetti Power Station Review (AC300) Off-grid Backup" (user Svarky) · 2023-10 · [negative]
- B4
“It still charges the battery from near empty to 100% in just over one hour, which is very good.”
Clean Energy Reviews Forum — "Bluetti Power Station Review (AC300) Off-grid Backup" (user Svarky) · 2023-10 · [positive]
- B5
“The AC300 + B300 has a little bit of noise coming from the fan. It's NOT silent. But considering the size and use case... you'll forget it's there.”
GreenCitizen — "Bluetti AC300 + B300 Power Station Review: Real-Life Lab Test Results" · 2025-01 · [positive]
- B6
“The powered fans within my AC300 units are extremely quiet when running – no detectible motor or bearing noise; only air movement is slightly heard.”
DIY Solar Power Forum — "Fan noise level of Bluetti AC200MAX?" thread (AC300 owner's comparison reply) · unknown · [positive]
- B7
“The companion app brings basic functionality to your fingertips but leaves you longing for more.”
GreenCitizen — "Bluetti AC300 + B300 Power Station Review: Real-Life Lab Test Results" · 2025-01 · [negative]
- B8
“App (v3.0.1) keeps loading indefinitely even when the AC300 itself shows it is "Connected."”
BLUETTI Community forum — "AC300+B300 doesn't connect to Bluetti App" thread · unknown · [negative]
- B9
“I just had my AC300 head unit fail with a007 App error, and 00 006 and 01 006 errors on the console screen and 2 days later.... click click click.. DEAD.”
DIY Solar Power Forum — "Bluetti - Screw you - AC300 dead and no parts to fix it anymore 5 years after launch" · 2026-03 · [negative]
- B10
“Due to the AC300 being discontinued, they don't have the necessary parts for repairs. Considering the repair costs and round-trip shipping fees, we don't recommend repairing it.”
DIY Solar Power Forum — "Bluetti - Screw you - AC300 dead and no parts to fix it anymore 5 years after launch" (Bluetti support reply relayed by OP) · 2026-03 · [negative]
- B11
“The Bluetti AC300 + B300 combo kept the fridge running for an average of 31 hours on a charge.”
Forbes — Brad Moon, "Review: Bluetti AC300 + B300 Home Battery Backup System" · 2023-10 · [positive]
Research compiled September 13, 2026.
Who Should Buy Which
Buy the DELTA Pro Ultra X if you…
- →You are backing up a panel rather than a few outlets: central air, a well pump, a 240V range. 12kW at 120/240V covers a whole house including a 5-ton ACA1, and 3,000W is not in that conversation.
- →Your array is already large or about to be. A 10,000W input ceiling means a ground mount can dump a day's generation into the bank inside a short window instead of trickling at it all afternoon.
- →You expect the bank to outgrow 12,288Wh. One inverter takes this platform to 61.44kWh and three take it to 184.32kWhA2, so what you buy on day one is a floor rather than a ceiling.
- →You want the thing you wire into your house to still be a current product the week it goes wrong, with five years of term standing behind it.
Buy the AC300 + 4×B300 if you…
- →Your worst hour is a fridge, a freezer, a furnace fan, the router and some lights, all running together and still inside 3,000W. Then you are buying the same 12,288Wh for $5,596 and the EcoFlow's output would sit idle for the life of the unit.
- →You have roof or wall space for a few panels, not a field. If 2,400W is more input than you will ever actually wire up, the 10,000W ceiling is a number on a page.
- →You are buying direct from BLUETTI and registering it, which takes coverage from two years to up to five and puts you in the channel where its support works best.
- →You would rather put the $2,403 into panels than into inverter capacity you cannot load.
If neither fits
If you want to take this power anywhere, close the tab. These weigh 298.7 lb and 367.2 lb, both are rated stationary, and a campsite or a tailgate needs something you can lift into a trunk, so shop the portables you can actually pick up instead. The other person who should walk away is the one whose real requirement is a fridge and a few outlets through an eight-hour outage. That is 1,645Wh, about a sixth of what either of these holds usable, and spending at least $5,596 on 12,288Wh to use one sixth of it is how a sensible backup plan turns into a garage ornament. A single mid-size unit does that job for a fraction.
The Bottom Line
Same battery, same rated cycles, same 43,008 kWh of life in each. Everything separating these two sits on the input and output side, and for $2,403 the DELTA Pro Ultra X is four times the machine there. If your circuit list needs any of it, the decision was made before you opened this page.
If your list does not need it, be honest with yourself before pocketing the saving. The AC300's batteries will outlive its head unit, and the one documented ending for that head unit is a dead console and a support reply about missing partsB9B10. Bought direct and registered, it is a sound $5,596 of storage with five years behind it. Bought anywhere else, you have saved $2,403 against a machine that is already being wound down.
Frequently Asked Questions
Answers drawn from the spec record and cited owner research.
Is the BLUETTI AC300 still supported?
Not in the way you would want on a $5,596 purchase. BLUETTI's support told an owner whose head unit died that the AC300 is discontinued, the repair parts are unavailable, and repair is not recommended once you add round-trip shipping. Coverage itself runs two years bought through a reseller and up to five bought direct and registered, so where you buy decides how much of that risk you personally carry. The B300 batteries are not the worry here; the inverter head is.
Do I actually need 12,000W of output for home backup?
Only if you are backing up the panel rather than picking circuits. 3,000W continuous will run a fridge, a freezer, a furnace fan and lighting simultaneously, and it will not run central air or a well pump. If the plan is to hand the whole house over to the battery at the breaker, 12kW at 120/240V is the spec that makes it possible.
Why do these cost so differently if they store the same amount of power?
Because the price difference is not buying storage. Both hold 12,288Wh at 3,500 rated cycles, which is 43,008 kWh of lifetime energy each. The $2,403 buys four times the continuous output, a far higher published surge peak, and a 10,000W solar input ceiling against 2,400W. Not one watt-hour of it is extra capacity.
How long will 12,288Wh run a refrigerator?
A Forbes test measured 31 hours of fridge runtime on an AC300 with one B300, which is 3,072Wh or a quarter of this stack. Four modules behind the same inverter works out near five days (31 hours times 4). That test ran on the real system, so the AC300's own idle consumption is already baked into the figure.
Can I put either of these in a van or an RV?
The energy math passes and the payload math does not. A full day of van-life use is 4,685Wh, about 45% of either unit's usable capacity, so neither would break a sweat. But 298.7 lb and 367.2 lb of battery is a suspension and axle-weight conversation, and neither unit's solar ceiling is reachable from a vehicle roof anyway. Both of these are building hardware.
Brand matchup
EcoFlow vs BLUETTI: measured across every matchup →Related comparisons
Where to buy
EcoFlow DELTA Pro Ultra XPick
$7,999.00
$7,999.00 · direct from EcoFlow
Last checked 16 days ago. Prices move — check before you buy.
BLUETTI AC300 + 4×B300
$5,596.00
$5,596.00 · direct from BLUETTI
Last checked 16 days ago. Prices move — check before you buy.
Prices may vary by retailer and are subject to change.