Head-to-head test
EcoFlow DELTA 3 vs BLUETTI Apex 300 + B500K
870 watt-hours is the line: under it the DELTA 3 does the job for $549, and over it the Apex bundle is the only one of the two that finishes.
Full profiles: EcoFlow DELTA 3 → · BLUETTI Apex 300 + B500K →
Written by Gunner GustafsonUpdated
Whole-Home Backup Tester, Station Arena Test Desk
$629.00 · direct from EcoFlow
Last checked 3 days ago. Prices move — check before you buy.
$3,299.00 · direct from BLUETTI
Last checked 3 days ago. Prices move — check before you buy.
Spec deltas
The DELTA 3 costs $549 and you carry it out to the truck with one hand. The Apex 300 with a B500K costs $3,299, weighs 183 lbs across two boxes, and once you have picked its corner you are not moving it again. These are not rivals. They are answers to two different questions, and the page is only useful if it tells you which question you are asking.
Run both through the six loads this site models and the DELTA 3 clears two. It handles a CPAP night with 550Wh spare and a tailgate evening with 200Wh spare. It misses a camping weekend by 1,230Wh, an eight-hour blackout by 775Wh, a van-life day by 3,815Wh, and a remote workday by 40Wh. The Apex bundle covers all six, and finishes the heaviest of them with 2,017Wh still in the bank.
Here is the part worth slowing down for: the expensive one is the cheaper energy. It is $.42 per watt-hour against $.54 on the sticker, and $0.12 per lifetime kWh against $0.18 across the cells' rated cycles. You do not buy the DELTA 3 because it is efficient with your money. You buy it because $549 is a number you can spend on a maybe, and because 27 lbs goes places 183 lbs never will.
What the Numbers Reveal
Each conclusion stated first — the numbers behind it on one line, the full analysis below.
Capacity
Cost-per-lifetime-kWh is a metric that rewards whoever drains the battery. Draw 5% a night and you will reach the 3,500-cycle rating somewhere well past your own retirement, so the $3,299 never amortizes into twelve cents of anything. The DELTA 3's 3,000 cycles on 1,024Wh do get used, because 1,024Wh is a size a normal evening finishes.
Apex 300 + B500K: $0.12 per lifetime kWh, from 3,500 cycles of 7,884.8WhDELTA 3: $0.18 per lifetime kWh, from 3,000 cycles of 1,024WhCPAP Overnight draws 320Wh, which is 5% of the Apex bundle's 6,702Wh usable
Why it mattersIf your loads are small, ignore the per-kWh column outright. It is the strongest number on the Apex bundle's side of this page and it is measuring a race you are not entering.
A 40Wh miss is the exact kind of failure an expansion port fixes, and the DELTA 3 has one. This is not a unit in the wrong class for a workday. It is a unit one accessory short of it. What our data does not include is what that accessory costs, so nobody can tell you from this page where the two curves cross.
Remote Workday needs 910WhDELTA 3 delivers 870Wh usable (85% of 1,024Wh)Shortfall: 40Wh, against an Apex bundle that finishes the same day at 14% usedDELTA 3 accepts EcoFlow expansion batteries
Why it mattersIf a full remote workday is your load, do not read the DELTA 3's red mark as disqualifying. Price an EcoFlow expansion battery before you price a $3,299 system.
solar input
That is not the Apex charging fast, it is input scaling with the bank. Bolt a battery onto the DELTA 3 and the 500W ceiling stays where it is, so off-grid you have bought more storage fed by the same daily harvest: more days to fill, not more energy per day. Grid-tied, none of this matters, because you refill from the wall while you sleep.
DELTA 3: 500W solar input into 1,024WhApex 300 + B500K: 2,400W solar input into 7,884.8WhBoth units are expandable, and expansion adds bank rather than input ceiling
Why it mattersVan dwellers and off-grid buyers should not treat DELTA 3 expandability as an answer to the Apex bundle. Blackout buyers with a working wall socket absolutely should.
A backup system is only as good as its worst firmware night. An inverter-output failure on a $549 box you keep in a closet is an annoyance you work around. The same failure on a two-box install wired in as your house backup is precisely the event you spent $3,299 to prevent, and several of those threads resolved only after further updates or a support callB8B10.
$3,299 for a 183-lb two-box install that gets sited onceFirmware and app updates have repeatedly left Apex 300 units mode-locked, unable to download, or throwing error codesB7B8B9B10One owner's charging stopped with an E004 Inverter Output Failure immediately after an updateB9Both units are rated at the same 10ms switchover
Why it mattersIf you buy the Apex bundle for backup, do not take a firmware update the week a storm is forecast.
The specific dimensions that decide these two units — everything else is a tie.
Your Life, Your Pick
Selected because: Six modeled loads, and the DELTA 3 clears two of them. This is where the decision actually gets made.
Two of six fit inside the DELTA 3 and four do not, and the four it misses are the ones people buy these things for. The camping weekend gap is the one to look at hardest: 1,230Wh short of a 2,100Wh weekend, which means the shortfall is larger than the battery. No amount of clever load management closes that. The Apex bundle takes it at 31% used.
One honest limit on this table. The scenario model has no class for an installed system, so Weekend Camping and Tailgate Party grade the Apex bundle as though its two boxes made the trip, and their scoring is built to reward the lighter unit for exactly that reason. It wins both on energy regardless. Read those two rows as arithmetic about watt-hours, not as advice about what to load into a car.
Portability & Form Factor
Selected because: 27 lbs against 183 lbs spread over two boxes: one of these travels and the other gets installed.
weight
27 lbs is a grab-the-handle-on-your-way-out weight. 183 lbs is not a heavier version of that, it is a different verb. And read the 183 carefully: it is the spec for the pair, the Apex 300 and the B500K together, the same way the 7,884.8Wh figure is. Our data does not split it by box, so treat it as an install total rather than a single lift, and be suspicious of anyone who quotes you a per-box number.
The field commentary lines up with the spec in the least surprising way possible. One reviewer could barely move an Apex 300 more than a few feet and could not get it onto a tableB11. If the unit ever has to leave the room it was installed in, this section already decided the page for you.
Lifetime Value
Selected because: The $3,299 unit is the cheaper energy on both the sticker and the lifetime math, which is not the same as being the cheaper buy.
cost / lifetime kWh
The per-kWh columns favor the Apex bundle and they are right to. They are also answering a different question than the one on the table, which is not which battery is cheaper to use but which cheque you can write. The warranty-year line says the same thing in a different costume: $110 a year of coverage against $660, on terms that are identical five years either way.
Cost-per-lifetime-kWh is a promise about the future, and only a buyer who drains the battery ever collects it. Nothing in this section is wrong. It is simply timing a race the small unit is not running.
Growth Path
Selected because: Both take expansion batteries, so the real question is what each one expands into.
solar input
The Apex bundle is already the expanded version. 7,884.8Wh is a 2,764.8Wh Apex 300 with 5,120Wh of B500K bolted to it, so on that side of the page you are buying the grown-up form on day one. The DELTA 3 is the opposite bet: 1,024Wh now, with the option to add later, which makes a wrong guess cheap to correct.
The catch on the DELTA 3's escape hatch is that the input ceiling does not grow with the bank. That is fine for a house with a wall socket and thin for a van roof, and it is the single best reason on this page to spend up rather than start small.
Brand Trust
Selected because: Identical five-year warranties, very different odds of a smooth claim.
Both warranties run five years. The difference is what happens when you need one. Our brand assessment puts BLUETTI's support as the most inconsistent in the category: heavily email-based with China timezone delays, and better outcomes buying direct than through a third-party order. On a $549 unit that is an irritation. On a two-box install you cannot pack up and ship back, it is the risk that should price the decision.
EcoFlow does not get a free pass either: polarized support experiences, no parts or service offered out of warranty, and an October 2025 recall of the DELTA Max 2000 over overheating. Worth one more note on the BLUETTI side, because it is genuinely counterintuitive. Its app rates 4.5 on both stores, the best in the category, and the Apex 300 threads are still full of updates that left units stuckB7B8B9. A good app and a good update pipeline turn out to be different products.
Strengths & trade-offs
EcoFlow DELTA 3
Strengths
- +Costs $2,670 less
- +Lighter by 156 lb
Trade-offs
- –Weaker inverter (-2,040W) limits appliance compatibility.
- –Shorter-lived battery — rated for 4,000 charge cycles vs the Apex 300 + B500K's 6,000, so it wears out sooner.
BLUETTI Apex 300 + B500K
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 (+$2,670) than the DELTA 3.
- –Significantly heavier (+156 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
Neither unit
A camping weekend asks for 2,100Wh. The DELTA 3 delivers 870, so it ends 1,230Wh short, which is a gap bigger than the whole battery. The Apex bundle covers it at 31% used with 4,602Wh still in reserve.
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 + B500K
1,645Wh across eight hours averages about 206W. The DELTA 3 stops 775Wh short of the end, which at that rate is roughly the last four hours of the outage. The Apex bundle covers all eight at 25% used and holds enough to do it four times over, which is the argument for it if your outages have a habit of running long.
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
A CPAP is about 40W for eight hours, so 320Wh, and both units cover that several times over. The percentages are a formality. Two specs settle it at this load: what it costs, and whether it fits beside a bed. The DELTA 3 is $549 and 27 lbs against $3,299 and 183 lbs for a job that uses a twentieth of the bigger unit's usable capacity, and since both are rated at the same 10ms switchover, a grid cut at 3 a.m. does not separate them either.
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 + B500K
910Wh needed against 870Wh usable. The DELTA 3 misses this one by 40Wh, under 5% of everything it can deliver, and a miss is still a miss because the day ends 40Wh early. The Apex bundle takes it at 14% used. Worth noting that this is the only row on the page where the DELTA 3 loses to a rounding error instead of to physics, and 40Wh is the size of gap an expansion battery closes.
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
Both run game day. 670Wh against the DELTA 3's 870Wh usable leaves 200Wh spare, and the Apex bundle finishes at 10% used, so the bigger unit wins the arithmetic this row measures. What the row does not measure is the tailgate itself: one of these rides in beside the cooler at 27 lbs, and the other is 183 lbs across two boxes to unload in a parking lot.
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 + B500K
4,685Wh a day is the one load here that makes the Apex bundle work for a living: 70% of usable capacity gone by bedtime, 2,017Wh left. The DELTA 3 is not in this conversation, 3,815Wh short, over four times what it delivers. For a van the binding number is not the bank but the refill, and putting 4,685Wh back through a 2,400W solar ceiling is about two hours of genuinely full sun, every single day.
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 + B500K runs 32.7h vs 4.2h.
$3,299 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 0–446.8hComfort & Convenience
Makes off-grid life actually enjoyablescale 0–89.4hHigh-Draw Appliances
These reveal the real limitsscale 0–6.7h¹ 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 9, 2026
Verdict: the EcoFlow DELTA 3
Take the DELTA 3 unless you can name a day that draws more than 870Wh, which is what its 1,024Wh actually delivers after the standard 85% derate. Under that line the $549 unit does the work and the $3,299 one is capacity you pay for and never spend, and because the DELTA 3 accepts EcoFlow expansion batteries, guessing low is a recoverable mistake. Over that line the DELTA 3 stops: 1,230Wh short of a camping weekend, 3,815Wh short of a van-life day. If that is your load, the Apex 300 with a B500K is the better machine and the cheaper energy besides, and you should buy it with your eyes open about 183 lbs, BLUETTI's support record, and a firmware history that has left Apex 300 units locked up after an updateB7B9.
Editor-assigned confidence, based on cited owner research and spec analysis.
List prices as of August 9, 2026. The links below open EcoFlow's and BLUETTI's current prices.
$629.00 · direct from EcoFlow
Last checked 3 days ago. Prices move — check before you buy.
or check the Apex 300 + B500K price$3,299.00 list
Written by Gunner Gustafson, Whole-Home Backup Tester · Station Arena Test Desk · Updated August 9, 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, CPAP, Solar Generator, Tailgating, 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 rates 4.7/5 (80th percentile of 26 Everyday-class units), and Apex 300 + B500K rates 3.5/5 (11th 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.
183 lbs, and Not in One Piece
The 183 lbs on the spec sheet covers the Apex 300 and the B500K together, the same way its 7,884.8Wh does. Our data does not split it by box, so read it as an install total rather than a single lift. The practical conclusion is unchanged either way: you choose a spot, run the cables, and it stays there. The DELTA 3's 27 lbs is a different category of object, not a lighter version of the same one.
45dB Under Load, and Where the Unit Ends Up
45dB is the Apex bundle's rated figure under load, against 30dB for the DELTA 3, and the useful way to read that is to ask where each unit lives. A 27-lb box can be carried to a bedside. A 183-lb two-box install goes in a utility room or a garage, where 15dB of difference costs you nothing at all. If you plan to sleep next to whatever is running your CPAP, the rating matters. If it is wired in two rooms away, it does not.
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 DELTA 3 works out at 9.1 years of cover per $1,000 spent against the Apex 300 + B500K's 1.5, but that spread is the price gap, not the terms.
Battery Lifespan in Real Years
The Apex 300 + B500K 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 7,885Wh on the Apex 300 + B500K and 1,024Wh on the DELTA 3, so count lifetime energy — roughly 47,309 kWh against 4,096 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.
Check DELTA 3 price →or check the Apex 300 + B500K 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 is cheaper to buy, but the Apex 300 + B500K is cheaper to own. At $0.07/kWh over its lifetime vs $0.13/kWh, the Apex 300 + B500K'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/chat support (1-800-368-8604). Experiences are polarized — many report hassle-free prepaid-label replacements, but others report long waits and refurbished units sent for new claims. Pro tip: buying from Costco or Amazon gives you a stronger return safety net.
Community
Largest community in the space — Reddit r/Ecoflow_community (~31K members), multiple Facebook groups, and an official community forum
App experience
Rated 4.6/5 iOS (~8,400 ratings) · 4.2/5 Android (~17,000 ratings)
Unique strength
Fastest-charging technology (X-Stream), deepest product ecosystem, and most active innovation cadence. At the 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 space. Heavily email-based with China timezone delays. Some users get smooth, efficient service; others report weeks of troubleshooting runarounds, being offered discounts on new units instead of repairs, and confusing third-party purchase claim processes. Buying direct from Bluetti's website tends to produce better support outcomes.
Community
Active and growing — Reddit r/bluetti has a dedicated community. Second-largest after EcoFlow in engagement.
App experience
Rated 4.5/5 iOS and Android — tied for best app experience in the category. V3.0 UI redesign was well-received.
Unique strength
Among the best capacity-to-price ratios available — several Elite and Apex units are the lowest $/Wh in the catalog. Widest product diversity including industry-firsts like sodium-ion cold-weather units and dual solar+alternator vehicle hubs. 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
EcoFlow positions itself as a mid-to-premium brand with stronger support infrastructure, while BLUETTI competes on value. The question is whether the EcoFlow ecosystem and support premium is worth it for your use case.
Growth path
DELTA 3
EXPANDABLESupports EcoFlow expansion batteries, so you can add capacity later without replacing the base unit — useful if your needs may climb past 1,024Wh.
Accepts up to 500W of solar. Suitable for a 1-2 panel setup.
Generous port selection supports complex multi-device setups.
Expansion batteries are EcoFlow-specific. You're investing in the EcoFlow ecosystem.
Apex 300 + B500K
EXPANDABLESupports BLUETTI expansion batteries, so you can add capacity later without replacing the base unit — useful if your needs may climb past 7,885Wh.
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
Both expand, but the Apex 300 + B500K's higher solar ceiling (2,400W vs 500W) 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 3
Field data on the standard DELTA 3 is thin, and most published testing covers the Plus, Max and Ultra variants instead, so read what follows as preliminary rather than settled. What is attributable to this model: under 200W the fans often do not spin at all, and between 500W and 800W they are barely audible from three feet awayA1. The UPS side is more caveated. The roughly 10ms handoff was observed on a DELTA 3 Plus that shares the same 10ms spec, not on this unitA2, so the switchover figure in the table is a spec nobody has yet confirmed on the standard model.
“At low loads (under 200W) the fans often stay completely off, making the Delta 3 effectively silent; under moderate load (500–800W) the fans are barely audible from three feet away.”
Sources
portablepowernerd.com · thesolarlab.com · outputreport.com
BLUETTI Apex 300 + B500K
Almost none of this is long-term ownership. The available commentary comes from BLUETTI's own forum, the DIY Solar Power Forum, a van forum and press reviews, and none of it covers this exact Apex 300 plus B500K pairing. The reviews are of the bare Apex 300 or of the B300K comboB2B5, and nothing turned up from anyone six months in. For a $3,299 purchase that is the most important sentence on the page: the evidence base is press loans and first impressions.
What owners do report clusters in two places. Firmware and app updates have repeatedly left Apex 300 units mode-locked, unable to download, or throwing error codes, including one charging session that stopped with an E004 Inverter Output Failure right after an updateB7B8B9, with several threads ending in a fix after more updates or a support callB8B10. Separately, owners running multiple Apex units or expansion batteries in parallel report them charging at uneven rates rather than together, with unofficial community workarounds to keep them in stepB3B4. Whether that reaches a base-plus-expansion pairing like this one is unknown, because nobody in the located sources ran this configuration.
Three independent reviewers describe the Apex 300's dual-fan cooling as quiet and even for its output class, one of them putting it on par with the quietest units EcoFlow and DJI makeB1B2B13. That sits awkwardly beside the 45dB rating in our own spec table, and the sensible reading is to plan against the rating and take the reviewers as evidence the noise is steady rather than whiny. One conflict I will name and then leave alone: a review states the Apex 300 has no USB or DC ports at all beyond its AC outlets and high-voltage connectorsB12, while our spec table lists 100W USB-C for it. I cannot resolve that from what I have, so no part of this verdict rests on ports in either direction.
“Turns out the Apex 300's noise control is on par with the quietest power stations on the market, like those on offer from EcoFlow and DJI.”
Sources & Research Notes
Every owner claim in this report is traceable to a published source. The bracketed references above resolve here.
Recurring owner themes
- Multiple independent reviewers describe the dual-fan cooling as noticeably quiet/even for a unit of this output class, even under load. [Apex 300 + B500K · 3 entries]
- Firmware and app updates have repeatedly caused mode-lock, download failures, or inverter error codes; several threads show the issue eventually resolved after further updates or support contact. [Apex 300 + B500K · 4 entries]
- When running multiple Apex 300 units or expansion batteries in parallel, owners report uneven charge rates between units, with community-devised (unofficial) workarounds needed to keep them in sync. [Apex 300 + B500K · 2 entries]
- The stripped-down, modular design draws criticism for real-world handling: extreme weight makes it hard to move, and lack of native USB/DC ports forces reliance on a separate paid hub accessory. [Apex 300 + B500K · 2 entries]
- A1
“At low loads (under 200W) the fans often stay completely off, making the Delta 3 effectively silent; under moderate load (500–800W) the fans are barely audible from three feet away.”
portablepowernerd.com — EcoFlow Delta 3 Tested: 2026 Hands-On Review; thesolarlab.com · 2026 · [positive]
- A2
“UPS switchover works as advertised — a power cut results in a ~10ms handoff, fast enough that routers don't reset, fridges don't skip a compressor cycle, and CPAP machines don't interrupt therapy.”
outputreport.com / thesolarlab.com — DELTA 3 line UPS testing (observed on DELTA 3 Plus, which shares the 10ms UPS spec) · 2026 · [positive]
- B1
“Turns out the Apex 300's noise control is on par with the quietest power stations on the market, like those on offer from EcoFlow and DJI.”
The Solar Lab — "Bluetti Apex 300 Review: Cheap, Practical Home Backup?" · unknown · [positive]
- B2
“Some units sound like small jet engines under load, but the Apex 300's fans are relatively tame.”
Techspective — "Bluetti Apex 300 with B300K Review" · 2025-09 · [positive]
- B3
“The Apex 300 have some major charging problems... When the units are charging from the grid they charge at different rates and not together.”
DIY Solar Power Forum — "Bluetti Apex 300 problems" · 2025-09 · [negative]
- B4
“I have found a simple way to get around some of the solar charging limitations with multiple APEX 300s hooked up in parallel... So far, I have not had any problems with my setup.”
DIY Solar Power Forum — "Bluetti Apex 300 problems" · 2025-09 · [mixed]
- B5
“So far so good. Works with external batteries. For small applications the solar available works OK. For me the 240V output is great.”
DIY Solar Power Forum — "Bluetti Apex 300 launched today… anyone have thoughts?" (page 2) · 2025-05 · [positive]
- B6
“I was looking at building a full system and it was getting very overwhelming and I'm hoping this may be the answer.”
VW T6 Transporter Forum — "Bluetti Apex 300" · 2025-07 · [positive]
- B7
“I updated my Apex 300 to the latest firmware yesterday. Now it's stuck in 'Backup' mode... when I go into the app to try to change it back, it flashes to...”
BLUETTI Community — "Apex 300 stuck in Backup mode after last firmware update" · 2025-11 · [negative]
- B8
“There was an update on my Apex 300 a few days ago IOT v8026.12... Problem is every time I connect to the power st[ation]... Edit - This seems fixed now hooray!”
BLUETTI Community — "Check For Update App issue" · 2025-09 · [mixed]
- B9
“After the update completed, the charging stopped and I received Error 004... I have error E004 Inverter Output Failure.”
BLUETTI Community — "Error E004 Apex 300" · 2025-11 · [negative]
- B10
“I had a power outage in the middle of the night, so I hooked everything (Hub A1 and all 300's) back up and now HA is populating. YEA!!!”
GitHub bluetti-official/bluetti-home-assistant — "APEX 300 and Hub A1 now working" (Issue #95) · 2026-05 · [mixed]
- B11
“it's so heavy I can hardly carry it more than a few feet at a time and have been unable to lift it onto a table.”
T3 — "Bluetti Apex 300 review: transform your off-grid life" · 2025-11 · [negative]
- B12
“The Apex 300 doesn't have USB ports, DC ports, or much of anything beyond its six AC plugs and high-voltage connectors.”
The Solar Lab — "Bluetti Apex 300 Review: Cheap, Practical Home Backup?" · unknown · [negative]
- B13
“Fan noise remains even, with no distracting pitch or rattle. This makes the Apex 300 usable near sleeping areas or indoor workspaces without disturbance.”
Yanko Design — "BLUETTI Apex 300 Review" · 2025-05 · [positive]
Research compiled August 9, 2026.
Who Should Buy Which
Buy the DELTA 3 if you…
- →The person whose worst night is a CPAP, a router, a couple of phones and a fan. That is 320Wh out of 870 usable, it costs $549, and it moves to whichever room you end up sleeping in.
- →Anyone buying a first power station without having measured their load. $549 buys you the data to make the $3,299 decision properly later, and the unit takes expansion batteries if the answer comes back bigger than 1,024Wh.
- →Tailgates, day trips, anything you personally carry. 27 lbs, and a 670Wh evening still leaves 200Wh in the tank.
Buy the Apex 300 + B500K if you…
- →The van or off-grid buyer with a measured daily draw near 4,685Wh. Nothing smaller on this page finishes that day, and this one finishes it with 2,017Wh left over.
- →Whole-home backup for outages that run past eight hours, where the 3,840W inverter matters as much as the bank. One owner singles out the 240V output as the specific reason the unit worked for himB5.
- →The buyer who priced a wired system out of individual components and flinched at the complexity. At least one forum poster arrived at the Apex exactly that wayB6.
If neither fits
If you want something genuinely portable that still covers a camping weekend or a full eight-hour outage, neither of these does it. The DELTA 3 is 1,230Wh short of the weekend and the Apex bundle is a two-box install. Shop the single-box middle of the market instead, somewhere between 1,024Wh and 7,884.8Wh with one handle and one price, and you get the capacity without the forklift.
The Bottom Line
Take the DELTA 3 unless you can name a day that draws more than 870Wh. It covers a CPAP night and a tailgate evening with room to spare, it costs $549, and being wrong about it is survivable because it expands. The Apex bundle beats it on nearly every line printed on this page, more capacity, cheaper energy, more solar, more inverter, and none of that helps a buyer who was never going to fill it.
If you can name that day, stop hedging and buy the Apex bundle, because the DELTA 3 does not come close on the loads that matter to you. Go in knowing what comes with it: 183 lbs you site once, the category's most inconsistent support organization, and a firmware record worth reading before you make this the thing your house depends onB7B9.
Frequently Asked Questions
Answers drawn from the spec record and cited owner research.
Is the BLUETTI Apex 300 + B500K worth six times the price of the EcoFlow DELTA 3?
Only if you use the capacity. $549 against $3,299 is $2,750 more, and while the Apex bundle is the cheaper energy on both the sticker and the lifetime math, a rate is not an outlay. If your heaviest day fits inside the DELTA 3's 870Wh usable, that $2,750 buys watt-hours you will never draw.
Can the EcoFlow DELTA 3 run a house during a blackout?
Not a whole one. It delivers 870Wh usable and a modeled eight-hour outage asks for 1,645Wh, so it covers roughly the first half and stops 775Wh from the end. Its 1,800W inverter is also half the Apex bundle's 3,840W, which limits what you can run at once, never mind for how long.
How heavy is the Apex 300 + B500K really?
183 lbs, and that figure covers both boxes together, the same way the 7,884.8Wh capacity does. Our data does not break it out per unit, so nobody should quote you a single-box weight from it. Practically it means one location, chosen once, with cables run to it. The DELTA 3 is 27 lbs.
Does the DELTA 3 expand enough to replace the bigger system?
The bank is not capped at 1,024Wh, since it takes EcoFlow expansion batteries. What does not grow is the 500W solar input, so off-grid you would be filling a larger battery through the same funnel while the Apex bundle feeds a bigger bank at 2,400W. For grid-tied backup the DELTA 3's path is real. For van life it is not.
Which one is quieter?
On the spec sheet the DELTA 3, at 30dB against 45dB, and under 200W its fans often stay off entirely. Reviewers describe the Apex 300's fans as quiet and even for a unit of its output, so the real-world gap may be narrower than 15dB implies. Both figures are under-load ratings, and the 183-lb unit is unlikely to be in your bedroom in the first place.
Brand matchup
EcoFlow vs BLUETTI: measured across every matchup →Where to buy
EcoFlow DELTA 3Pick
$629.00
$629.00 · direct from EcoFlow
Last checked 3 days ago. Prices move — check before you buy.
BLUETTI Apex 300 + B500K
$3,299.00
$3,299.00 · direct from BLUETTI
Last checked 3 days ago. Prices move — check before you buy.
Prices may vary by retailer and are subject to change.