Head-to-head test
EcoFlow DELTA 3 Ultra vs BLUETTI Apex 300 + B300K
Everything on this page rides on one question: does your worst day fit inside 3,072Wh? If it does, the Apex 300 + B300K is a second power station's worth of money buying headroom you'll never reach. If it doesn't, nothing the DELTA 3 Ultra does about price can save it.
Full profiles: EcoFlow DELTA 3 Ultra → · BLUETTI Apex 300 + B300K →
Written by Gunner GustafsonUpdated
Whole-Home Backup Tester, Station Arena Test Desk
$1,399.00 · direct from EcoFlow
Last checked 1 day ago. Prices move — check before you buy.
$2,599.00 · direct from BLUETTI
Last checked 1 day ago. Prices move — check before you buy.
Spec deltas
$1,299 buys 3,072Wh. $2,599 buys 5,529.6Wh. The step between them costs $1,300 for 2,457.6Wh, or about $0.53 per added watt-hour, which is dearer than either unit charges for the energy already inside it ($0.42/Wh for the Ultra, $0.47/Wh for the Apex bundle). The priciest watt-hours in this matchup are the ones you'd be upgrading into.
What the extra money actually buys is a shorter afternoon and a longer future. The Apex swallows 2,400W of solar against the Ultra's 800W, and it takes BLUETTI expansion batteries, so 5,530Wh is where it starts rather than where it stops. The Ultra doesn't grow. It's a sealed box, complete the day it ships and complete forever. Both spec sheets list 100W USB-C, but the Apex's lives on the Hub D1 you buy separately, not on the unit's own faceB1B2.
The cost of the upgrade is one you feel with your body. 148.8 lb of stacked battery against 72.1 lb: one is a two-piece system you position once and then leave alone, the other is a lift you can manage by yourself if you bend your knees and mean it. Then 45dBA against 30dBA, which is nothing across a garage and everything across a bedroom. Five of the six loads modeled here fit inside the Ultra. The one that doesn't is a full day of van life.
What the Numbers Reveal
Each conclusion stated first — the numbers behind it on one line, the full analysis below.
Capacity
Which means the upgrade isn't a capacity purchase, it's an infrastructure purchase. The same money buys three times the solar input and an expansion port that turns 5,530Wh from a ceiling into a floor. Count watt-hours alone and the Apex bundle looks like a poor trade. Count how fast you can put energy back and how far the system can grow, and it's the only one of the two that scales at all.
DELTA 3 Ultra: $1,299 for 3,072Wh, listed at $0.42/WhApex 300 + B300K: $2,599 for 5,529.6Wh, listed at $0.47/WhThe gap between them is $1,300 for 2,457.6Wh
Why it mattersIf you can't say out loud why you need three times the panel input or room to grow past 5,530Wh, buy the Ultra and keep the difference.
solar input
Those two specs stop being independent the moment the battery is your only power, because living off it means emptying and refilling it every single day. A 4,685Wh day is beyond the Ultra to store and beyond it to replace inside a short winter window. The Apex swallows the day and gets it back in a morning. One tester had the whole system ready to go again in under an hour on shore powerB12, and the panel ceiling is the off-grid version of that same trick.
DELTA 3 Ultra: 800W maximum solar input into 3,072WhApex 300 + B300K: 2,400W maximum solar input into 5,529.6WhVan Life Daily draws 4,685Wh — 179% of the Ultra's usable capacity, 100% of the Apex's
Why it mattersIf your refills come off panels instead of a wall outlet, buy the Apex and stop reading the price tags.
That gap is a design thesis, not an oversight. The Apex is built to be set down once and fed through AC, and reviewers who've handled the stack call it too big and heavy for one person to shiftB5B14. One of them got 8W out of the B300K's own DC output while charging a phoneB6. The Ultra carries its ports on its face and its weight in your hands, and both of those choices say the same thing about where it expects to live.
The Apex 300's own face carries its AC outlets and high-voltage connectors; the USB and DC ports arrive on the separately sold Hub D1B1The Hub D1 runs about $300 on top of the $2,599 bundleB2The DELTA 3 Ultra carries its 100W USB-C on the unit itself
Why it mattersJudge the Apex as installed backup, where the missing ports cost you nothing, and the Ultra as the one that actually goes places.
weight
What's left is what it's like to sleep beside. The machine is an arm's length from your head from midnight to six, and these two sit fifteen decibels apart. Reviewers say the Ultra's fans never turn annoying or distracting even with the inverter pushed to its maximum outputA1A2. The Apex holds more than seventeen times a CPAP's overnight draw (5,529.6 divided by 320) and weighs twice as much, and not one watt-hour of that helps you sleep.
DELTA 3 Ultra: 30dBA, 72.1 lbApex 300 + B300K: 45dBA, 148.8 lbA CPAP night draws 320Wh — 12% of the Ultra's usable capacity, 7% of the Apex's
Why it mattersIf the unit is going in a bedroom, take the quiet one and ignore the capacity column entirely.
The specific dimensions that decide these two units — everything else is a tie.
Your Life, Your Pick
Selected because: Five of the six loads modeled here fit inside 3,072Wh. The sixth is the whole argument for spending more.
Winning a scenario and being the only unit that can do it are different things, and the Apex wins five of six the first way. The Ultra finishes a 2,100Wh camping weekend at 80% of usable, a 1,645Wh blackout at 63%, a 910Wh workday at 35%, a 670Wh tailgate at 26%, and it ties the Apex outright on the CPAP night. Reserve is worth something, because reserve is what covers the load you forgot to count. It just isn't the same thing as capability.
Then there's the day that ends the conversation. Van Life Daily wants 4,685Wh, which is 179% of what the Ultra can usefully hold. That's not tight, and it's not a rationing problem you can plan your way around. It's out of reach. The Apex covers it at exactly 100% of usable, a win with nothing behind it, so one overcast afternoon or one hot night with the fridge cycling hard leaves you short. That's the moment BLUETTI's expansion battery stops being a bullet point and becomes the reason you bought the thing.
Portability & Form Factor
Selected because: One of these you lift alone at 72.1 lb; the other you position once at 148.8 lb and leave. That outranks every other spec for anyone who plans to move it.
weight
72.1 lb is a bent-knees, both-hands, one-trip lift into a truck bed. Awkward and repeatable, which is exactly what lets the Ultra be a house unit that also goes camping twice a year. The Apex is a different species of object: two boxes stacked, near 150 pounds by the account of reviewers who've moved it, shiftable with the built-in handles or a trolley but never something you casually haul to a picnicB5, and one says flatly it's too big for most people to move aloneB14.
Settle this before you settle anything else, because it's the hardest thing to change later. Basement, utility closet, fixed van install? The Apex's weight costs you one afternoon and then never again. In and out of a vehicle every other weekend? The weight is the whole story, and the fan under load is the second reminder that this system was designed to be installed rather than carried.
Growth Path
Selected because: The Ultra is finished the day it ships. The Apex starts at 5,530Wh and keeps going.
solar input
A sealed box that covers your load is a finished system, not a crippled one, and the Ultra's ceiling clears five of the six loads here. Fixed capacity only costs you when the rival's ceiling is genuinely higher, and in this pair it is. The Apex starts at 5,530Wh and takes more BLUETTI batteries on top of it. One reviewer tried a roundabout way of stretching runtime and concluded the clean answer was simply adding a proper B300K to double the capacityB11, which is the same argument in an owner's language.
Before you pay for headroom, price it. The jump to 5,529.6Wh is the most expensive energy on this page, and every battery after it is another purchase at BLUETTI prices. Expansion is good insurance against a load you can name. It's a poor hedge against a vague feeling that your needs might grow.
Lifetime Value
Selected because: The cheaper box to buy turns out to be the cheaper box to run, which is not the usual trade.
cost / lifetime kWh
The cheaper box is also the cheaper energy, which is not how this usually goes. 4,000 cycles across 3,072Wh give the Ultra 12,288 kWh over its life for $1,299, or $0.11 a kilowatt-hour. The Apex bundle's 3,500 cycles across 5,529.6Wh give 19,354 kWh for $2,599, or $0.13. On weekend duty that's $0.09 a day against $0.21.
Here's the arithmetic that gives the game away: two DELTA 3 Ultras cost $2,599 and hold 6,144Wh. A dollar less than the Apex bundle, for more total energy. Nobody should actually do that, because two units are two islands with two arrays and two sets of circuits while the Apex is one 3,840W system that grows. But it tells you what the premium is really for. You aren't buying watt-hours. You're buying the fact that they all sit on one bus.
What the Specs Don't Tell You
Selected because: Weight, the fan under load and the Ultra's fixed ceiling are the flags that move a decision here. The matched 5-year warranties don't.
rated cycles
The word portable is doing heavy lifting in this category, which is why the weight flag fires for both of these and why both deserve it. The noise card is the one that follows you home: the gap between them is a curiosity across a garage and unmissable across a bedroom. The warranty card is a genuine dead heat at 5 years each, so read it and move on.
The expansion flag points straight at our own pick and we won't soften it. The Ultra is sealed at 3,072Wh, and if your draw outgrows that, your upgrade path is a second power station rather than an add-on battery. For most people that never bites. If you already know your loads are climbing, it's the one reason on this page to pause.
Strengths & trade-offs
EcoFlow DELTA 3 Ultra
Strengths
- +Costs $1,200 less
- +Lighter by 76.7 lb
Trade-offs
- –Sealed capacity — the Apex 300 + B300K can add batteries to grow past 3,072Wh; this one can't.
- –Shorter-lived battery — rated for 4,000 charge cycles vs the Apex 300 + B300K's 6,000, so it wears out sooner.
BLUETTI Apex 300 + B300K
Strengths
- +Larger battery capacity
- +Higher AC output
- +Faster solar charging
- +Rated for 6,000 charge cycles — much longer battery lifespan
Trade-offs
- –Substantially more expensive (+$1,200) than the DELTA 3 Ultra.
- –Significantly heavier (+76.7 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
A 2,100Wh weekend leaves the Ultra at 80% used and the Apex at 45%, so the Apex takes this one on reserve and comes home with more than half its charge untouched. Price that reserve honestly, though. It costs a second power station's worth of money and a second pair of hands at the tailgate, for a trip both units finish standing up.
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
Apex 300 + B300K
Neither unit breaks a sweat on a 1,645Wh outage: 63% of usable for the Ultra, 35% for the Apex, which is why the Apex takes it. Both hand over in 10ms, so nothing in the house notices the grid left. If your outages tend to run past a day, though, reserve stops being the deciding spec and panel input takes over, and there the Apex has three times the ceiling.
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
A 320Wh night is a rounding error for both machines, 12% of the Ultra's usable capacity against 7% of the Apex's, so this one's a dead heat and there's no sense pretending otherwise. Break it on what you'd actually notice at 3 a.m.: 30dBA against 45dBA an arm's length from your ear, and a unit one person can carry into the bedroom against a stack that isn't going up any stairs. Both tiebreaks point the same way.
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
Apex 300 + B300K
The Apex 300 + B300K clears the workday at 19% used, banking 3,790Wh — late work, extra calls, or a second laptop charge without arithmetic. The DELTA 3 Ultra at 35% also finishes, with 1,701Wh of slack for the unplanned.
Battery budget usedlower = more headroom
LOAD Laptop 60W×8h · External Monitor 30W×8h · Router + Modem 20W×8h · Phone Charger 15W×2h
SCN-05 · 4 hours · needs 670Wh
Tailgate Party
Game day power for the crew
DELTA 3 Ultra
The Apex 300 + B300K at 148.8 lbs is not a take-along — it rolls off a truck bed if it travels at all, so this scenario belongs to the DELTA 3 Ultra by default — and it earns it, covering the 670Wh with 1,941Wh to spare. Capacity was never the Apex 300 + 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
Apex 300 + B300K
This is the day the Ultra can't do. 4,685Wh is 179% of what it can usefully hold, which isn't tight, it's out of reach. The Apex clears the bar with nothing to spare, at exactly 100% of usable, so one overcast afternoon and you're short. Buy this system planning on a second BLUETTI battery and it's a fine buy. Buy it expecting the base bundle to carry an average day forever and it will disappoint you on the first bad one.
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: Apex 300 + B300K runs 22.9h vs 12.7h.
$2,599 list · direct from BLUETTI
Modeled from the spec record — same math as the tables below. Methodology
Runtime by appliance
Real-world runtime estimates for common appliances, modeled at 85% inverter efficiency.¹
Essentials
The basics you need runningscale 0–313.3hComfort & 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
August 2, 2026
Verdict: the EcoFlow DELTA 3 Ultra
Buy the DELTA 3 Ultra at $1,299 unless you can name the load that breaks it. It handles five of the six scenarios modeled here. The sixth is a full van-life day at 4,685Wh, which needs 179% of what the Ultra can usefully hold, and no accessory fixes that: it's a sealed box with no expansion port, so 3,072Wh is both the number you buy and the number you're stuck with. The Apex 300 + B300K is the bigger machine on every axis you'd expect. 5,529.6Wh, 2,400W of solar input, room to stack more BLUETTI batteries on top. It's also $1,300 more, twice the weight at 148.8 lb against 72.1 lb, and it runs 45dBA under load where the Ultra sits at 30dBA. The lifetime math doesn't rescue it either, at $0.13 per lifetime kWh against $0.11. So: if your draw is daily and off-grid, buy the Apex and don't look at the price gap. Everywhere else the Ultra wins on every axis that isn't capacity.
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 1 day ago. Prices move — check before you buy.
or check the Apex 300 + B300K price$2,599.00 list
Written by Gunner Gustafson, Whole-Home Backup 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): UPS, RV Living, 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 — 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 4.7/5 (80th percentile of 26 Large-class units), and Apex 300 + B300K rates 4.4/5 (67th percentile of 16 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.
148.8 lb Against 72.1 lb, and What That Means on Stairs
Neither of these is a one-handed carry, but they fail portability in different ways. The Ultra's 72.1 lb is a bent-knees, both-hands lift into a trunk: awkward, doable, and you can do it again next weekend. The Apex is a 148.8 lb two-piece stack you position once and then arrange the room around. Work out where each one is going to live before you pick one, because that's the part of this decision you can't undo later.
45dBA Under Load, and Where That Lands
The Apex runs 45dBA under load; the Ultra sits at 30dBA. In a garage, a basement or a utility closet that difference is a spec-sheet curiosity you'll never think about again. In a bedroom, a small van or an RV where the unit is a few feet from your head, it's the thing you notice every night, and no amount of extra capacity buys the quiet back.
The DELTA 3 Ultra Is Sealed at 3,072Wh
Fixed capacity isn't a flaw when the capacity covers you, and 3,072Wh covers five of the six loads modeled here. But fixed means fixed: no expansion port, no add-on battery, no upgrade path in two years when the loads have crept up on you. The Apex starts at 5,530Wh and takes more BLUETTI batteries on top. If there's a real chance your draw outgrows the Ultra, its only answer is a second power station, and that's the honest case against our own pick.
Matched 5-Year Terms, Different Price Per Year
Both carry 5 years, so the term itself decides nothing. What differs is what a year of that coverage costs: $260 on the DELTA 3 Ultra against $520 on the Apex 300 + B300K. Read this column as the tie it is, then go settle the argument on capacity and price, where it actually lives.
Battery Lifespan in Real Years
The Apex 300 + B300K is rated for 6,000 cycles vs 4,000. In real life: at daily use, that's 16.4 vs 11 years. At weekend use (twice a week), it's 58 vs 38 years. One caution reading years across different sizes: a cycle is 5,530Wh on the Apex 300 + B300K and 3,072Wh on the DELTA 3 Ultra, so count lifetime energy — roughly 33,178 kWh against 12,288 kWh over the rated life. After hitting the cycle limit, the battery doesn't die — it drops to ~80% of original capacity, which is still very usable.
Full record above — the Test Desk pick is the DELTA 3 Ultra.
Check DELTA 3 Ultra price →or check the Apex 300 + B300K 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 DELTA 3 Ultra is cheaper to buy, but the Apex 300 + B300K is cheaper to own. At $0.08/kWh over its lifetime vs $0.11/kWh, the Apex 300 + B300K'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 phone, email and chat, and the experiences split hard down the middle. Plenty of buyers get a prepaid label and a replacement without a fight. Others wait weeks and get a refurbished unit against a claim on a new one. Buying through Costco or Amazon gives you a second return path that EcoFlow's own process doesn't.
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
EcoFlow runs the deepest ecosystem in portable power and the fastest charging in it, but offers no parts or service once the warranty lapses. Year six isn't a repair bill, it's the end of the road.
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 weakest link in an otherwise strong package. Support is mostly email and runs on China timezones, and outcomes swing from efficient to weeks of runaround, including offers of a discount on a new unit instead of a repair on the one you own. Buying direct from BLUETTI rather than through a third-party seller measurably improves how a claim goes.
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
What BLUETTI is genuinely good at is value and breadth. Several Apex and Elite units are among the lowest cost per watt-hour you can buy, the whole lineup is LFP rated at 3,500 cycles or better, and the app scores 4.5/5 on both platforms after its V3.0 redesign.
Analyst note
At these prices support is part of the product, not a footnote. EcoFlow's is inconsistent but there's a US phone number to ring. BLUETTI's is the most inconsistent in the category and mostly email. On the cheaper box that risk is an annoyance you'd absorb. On the system that might end up being your house's backup, it's worth buying direct from the manufacturer so a claim has the shortest path to a human.
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.
Apex 300 + 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 2,400W of solar. Enough for a serious multi-panel array.
Generous port selection supports complex multi-device setups.
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
The DELTA 3 Ultra is sealed at 3,072Wh, which is fine if that covers you. The Apex 300 + B300K starts at 5,530Wh and can grow beyond it with BLUETTI expansion batteries — real headroom the DELTA 3 Ultra doesn't have if your needs climb toward partial-home backup.
What Owners Report
Patterns from published owner reports and long-term reviews — every claim cited to its source below.
EcoFlow DELTA 3 Ultra
Everything known about the DELTA 3 Ultra in the field comes from reviewers with test units rather than owners three winters inA1A5A9, so read it as early signal, not a track record. Two things come up every time. The fans: much quieter than older EcoFlow units like the DELTA 2 Max, and never annoying or distracting even with the inverter pushed to its maximum outputA1A2. And the handoff when the power dies: testers who yanked the wall plug mid-session saw no dip and no shutdown, one of them comparing it to the APC gear they'd spent a career aroundA5A6. It also refuses to clamp its output down to match input wattage while charging through, which plenty of stations doA4.
The complaints are small and specific, which is its own kind of reassurance. One tester found the unit drops its 30A port first, every time, when you push it past the limitA3. Worth knowing if that circuit is carrying something you'd rather not lose. Another couldn't read the display in direct sun without cupping their hands around itA11. On build, the shell, the AC cable and the sliding rear port covers all get singled out as unusually well madeA9A15. For real numbers: one reviewer ran a laptop, a desktop workstation and monitors through a full eight-hour workday and finished at 40%, then measured a little over 4.5 hours at a sustained 300W to 600W drawA7A8. Both are heavier days than the 910Wh workday the scenario table models.
“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 Apex 300 + B300K
The Apex 300 + B300K is new enough that its field record is review units rather than owner threadsB4B9B12; nobody has posted a two-year reliability report or an idle-drain log for this exact bundle yet. What testers agree on is what it does when you point it at real appliancesB4B12. One ran a full washing machine cycle that took it from 100% to 65%, then set a heat-pump dryer on it and watched another hour and a half pull it down to 20%B9B10. Another called it one of the few systems they'd tested that could genuinely replace a generator, without the noise, the fumes or the maintenanceB4. Recharge draws the same reaction every time: one tester had it ready to go again in under an hourB12.
The criticisms all point at the same empty surface. The Apex 300 gives you six AC plugs and its high-voltage connectors and very little else, with the USB and DC ports living on the Hub D1, a separate purchase at about $300 that more than one reviewer thought steep for what it addsB1B2. One got a measly 8W out of the B300K's own DC output trying to charge a phone, and found the app reporting flow but no percentage for that portB6B7. None of that matters in a utility closet. All of it matters in a van.
“The Apex 300 doesn't have USB ports, DC ports, or much of anything beyond its six AC plugs and high-voltage connectors.”
Sources
thesolarlab.com · techspective.net · digitalreviews.net · thesolarpit.com · cleantechnica.com · trustedreviews.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
- 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]
- Reviewers consistently flag that the base Apex 300 has no USB/DC ports and requires a separate paid Hub D1 accessory, which some feel is overpriced for what it offers. [Apex 300 + B300K · 3 entries]
- Multiple sources note the extreme weight/bulk of the stacked Apex 300 + B300K system, making 'portable' a stretch despite handles/trolley options. [Apex 300 + B300K · 2 entries]
- Reviewers praise fast recharge and the system's ability to genuinely replace a generator for home backup and heavy loads like washers/dryers. [Apex 300 + B300K · 4 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]
- A4
“Many power stations limit you to the input wattage when outputting power, but this EcoFlow power station does not.”
thesolarlab.com — EcoFlow DELTA 3 Ultra Plus Review: The Ultimate DELTA? · 2025-09/10 (approx) · [positive]
- 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
“The Apex 300 doesn't have USB ports, DC ports, or much of anything beyond its six AC plugs and high-voltage connectors.”
thesolarlab.com — Bluetti Apex 300 Review: Cheap, Practical Home Backup? · unknown (2025/2026) · [mixed]
- B2
“That Bluetti D1 Power Hub that gives you your DC and USB ports costs about $300, which is a steep price for what you're getting.”
thesolarlab.com — Bluetti Apex 300 Review: Cheap, Practical Home Backup? · unknown (2025/2026) · [negative]
- B4
“It's one of the few systems I've tested that feels like it could genuinely replace a generator, without the noise, fumes, or maintenance.”
techspective.net — Bluetti Apex 300 with B300K Review · 2025-09-21 · [positive]
- B5
“Stacked, you're near 150 pounds of lithium iron phosphate and inverter muscle—movable with the built-in handles or a trolley... but not something you'll casually lug to a picnic.”
techspective.net — Bluetti Apex 300 with B300K Review · 2025-09-21 · [mixed]
- B6
“I just wonder why Bluetti did not include a USB-C port with some decent output, like 100 or 140W as I only got a measly 8W charge out of it for my phone.”
digitalreviews.net — Bluetti B300K Expansion Battery Review · 2025-12 · [negative]
- B7
“It did not even show the percentage on the app but only that there was a DC output flow and indeed my tablet was charging.”
digitalreviews.net — Bluetti B300K Expansion Battery Review · 2025-12 · [negative]
- B9
“Results: 1 wash took about 1 hour and drained the Apex from 100% down to 65%.”
digitalreviews.net — Bluetti Apex 300 Power Station Tests (Australia) Part II · 2025-09 · [positive]
- B10
“Just for fun we then turned on our heat pump dryer to see that over 1½ hours it would further drain it down to 20%.”
digitalreviews.net — Bluetti Apex 300 Power Station Tests (Australia) Part II · 2025-09 · [mixed]
- B11
“You can see, that whilst this works in a very roundabout way, it is not as neat and efficient as having a proper B300K battery to double the capacity.”
digitalreviews.net — Bluetti Apex 300 Power Station Tests (Australia) Part II · 2025-09 · [mixed]
- B12
“During my testing, the recharge speed was astonishing. In under an hour, I had a system ready to go again.”
thesolarpit.com — Bluetti Apex 300 Review · 2025-10-28 · [positive]
- B14
“As will you: it weighs in at 38kg, and is probably much too big and heavy for most people to carry alone.”
trustedreviews.com — Bluetti Apex 300 Review · 2025-10-10 · [negative]
Research compiled August 2, 2026.
Who Should Buy Which
Buy the DELTA 3 Ultra if you…
- →You want one box that covers the blackout, the work-from-home day and two camping trips a year. A 1,645Wh outage costs the Ultra 63% of usable and a 2,100Wh weekend 80%, and it still goes in the back of a car.
- →You're the one sleeping next to it. 30dBA against 45dBA, and a CPAP night costs 12% of the battery, so there's nothing the bigger unit can offer you between midnight and six.
- →You recharge from a wall outlet, which is exactly where the Ultra's 800W solar ceiling stops mattering.
- →You care what a decade of this costs, not what a weekend costs: 4,000 cycles against 3,500, on the box that's already the cheaper energy per kilowatt-hour.
- →You want USB and DC ports on the machine you actually paid for, with nothing else to orderB1B2.
Buy the Apex 300 + B300K if you…
- →You're living off it every day, on purpose. 4,685Wh is 179% of what the Ultra can hold and 100% of what the Apex can, and no amount of careful budgeting closes that.
- →The sun is your only outlet. 2,400W of input puts a full charge back in under two and a half hours of hard sun.
- →You want a system with a second act: 5,530Wh is the Apex's floor, and BLUETTI batteries stack on top without replacing the base unit.
- →You want the generator gone, and the unit will be sited once and left alone. Testers ran a washing machine and a heat-pump dryer off itB9B10, and one judged it a real generator substituteB4.
If neither fits
Close this tab and buy something smaller if what you pictured was a battery you carry one-handed to a campsite. Both of these are furniture. A lighter portable does a weekend for a fraction of the weight and a fraction of the money, and you'll enjoy it more. Close it too if what you actually want is the whole house backed up through a transfer switch for days at a stretch: that's a permanently installed home battery or a standby generator, and stretching a portable to cover it costs more and delivers less.
The Bottom Line
Buy the DELTA 3 Ultra. It covers five of the six loads here, it's the cheaper box and the cheaper energy, you can lift it alone, and it's the quiet one. The Apex 300 + B300K is the bigger system and the wrong purchase for anyone who can't point at the specific day it saves.
That day is real and it's narrow: a full off-grid draw every day, or refills that have to come off panels instead of a wall. The Apex answers both, and there's no version of the Ultra that gets there, because what you buy is the ceiling. Everyone else: take the $1,299 box and keep the difference.
Frequently Asked Questions
Answers drawn from the spec record and cited owner research.
Is the BLUETTI Apex 300 + B300K worth $1,300 more than the EcoFlow DELTA 3 Ultra?
Only if you can name the load that breaks the Ultra. The gap between $2,599 and $1,299 buys 2,457.6Wh of extra capacity, about $0.53 per added watt-hour, which is more than either unit charges for the energy already inside it. What justifies the spend isn't the capacity, it's the 2,400W solar ceiling and the expansion port. If you recharge from a wall and your day fits inside 3,072Wh, it isn't worth it.
Does the BLUETTI Apex 300 have USB ports?
Not on the unit itself. Its face carries the AC outlets and the high-voltage connectors, and the USB and DC ports arrive on the Hub D1, a separate purchase reviewers put at around $300. So the 100W USB-C figure in the spec table describes that accessory rather than anything in the box. The DELTA 3 Ultra's 100W USB-C is on the unit.
Will the EcoFlow DELTA 3 Ultra get me through an 8-hour blackout?
Yes, with room left over. The eight-hour outage modeled here draws 1,645Wh, or 63% of usable capacity, and the 10ms switchover means the desktop and the router never notice the grid left. Testers who pulled the wall plug mid-session saw no dip and no shutdown. The limit is the multi-day version: at 800W of solar input, refilling 3,072Wh takes about four hours of strong sun, so a run of grey days forces you to ration.
Which is better for van life, the DELTA 3 Ultra or the Apex 300 + B300K?
The Apex 300 + B300K, and it's not close. A van-life day as modeled here draws 4,685Wh, which is 179% of the Ultra's usable capacity, so the Ultra can't finish the day at any level of discipline. The Apex covers it at exactly 100%, and that figure is worth reading twice: no margin. Budget for a second BLUETTI battery if your days run above average. The weight only costs you once, on installation day.
Which one is quieter to sleep next to?
The DELTA 3 Ultra, at 30dBA against the Apex's 45dBA. Reviewers say its fans stay unobtrusive even with the inverter at maximum output. A CPAP night draws 320Wh, which is 12% of the Ultra's usable capacity, so there's no capacity argument for dragging the louder two-piece stack into a bedroom.
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 1 day ago. Prices move — check before you buy.
BLUETTI Apex 300 + B300K
$2,599.00
$2,599.00 · direct from BLUETTI
Last checked 1 day ago. Prices move — check before you buy.
Prices may vary by retailer and are subject to change.