Head-to-head test
EcoFlow DELTA Pro vs BLUETTI Apex 300 + B500K
The Apex takes every scenario on the scoreboard and earns exactly one of them: unless your day clears the DELTA Pro's 3,060Wh of usable energy, the extra $1,700 buys a second box full of power you never spend.
Full profiles: EcoFlow DELTA Pro → · BLUETTI Apex 300 + B500K →
Written by Gunner GustafsonUpdated
Whole-Home Backup Tester, Station Arena Test Desk
$1,899.00 · 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
Five of the six days we model finish with the DELTA Pro still holding at least 960Wh in reserve. The sixth, a full-time van-life day at 4,685Wh, breaks it outright: 3,060Wh usable against a 4,685Wh draw, short by 1,625Wh. Below the DELTA Pro's ceiling these two do the same job. Above it, only one of them works.
Price says the same thing from the other end. $1,599 against $3,299, and the energy costs almost exactly the same either way: 44 cents a watt-hour for the DELTA Pro, 42 for the Apex. Same 3,500-cycle rating, same five-year warranty. You are not buying a better deal with the extra $1,700, you are buying more of the identical deal.
And a second box. The Apex 300 + B500K's 183 lbs is a system weight spread across two units, the 2,764.8Wh Apex 300 chassis and the 5,120Wh B500K that makes up the rest of the 7,884.8Wh, which is why it wants a spot on a floor rather than a spot in a trunk. The DELTA Pro is 99 lbs in one shell that rollsA2. So: DELTA Pro unless you have measured a day above 3,060Wh, and then the Apex, because nothing else on this page will do it.
What the Numbers Reveal
Each conclusion stated first — the numbers behind it on one line, the full analysis below.
Capacity
Van Life Daily is the only modelled day inside the window, and inside it the result is absolute: the DELTA Pro comes up 1,625Wh short while the Apex finishes at 70% used with 2,017Wh still in hand. On the other five days the extra capacity sits there being expensive.
DELTA Pro: 3,600Wh rated, 3,060Wh usable after the 85% inverter derateApex 300 + B500K: 7,884.8Wh rated, 6,702Wh usableFive of the six modelled days draw 2,100Wh or less; the sixth, Van Life Daily, draws 4,685Wh$1,599 against $3,299
Why it mattersPut a plug meter on your real loads for one day before you spend. The reading either clears 3,060Wh or it doesn't, and that single number picks the unit.
solar input
That is what makes daily off-grid cycling a different question from occasional backup. A rig spending 4,685Wh a day has to put all of it back the same day, and the Apex can do that inside one good solar window. The DELTA Pro cannot hold the day in the first place, so its faster fill time is answering a question nobody asked.
DELTA Pro accepts 1,600W of solar into 3,600WhApex 300 + B500K accepts 2,400W of solar into 7,884.8WhVan Life Daily consumes 4,685Wh every day, not once
Why it mattersIf you are living off the panels rather than topping up between trips, the solar ceiling counts as much as the battery, and it goes to the Apex without argument.
So no per-dollar framing rescues either side. A coverage-per-dollar figure that appears to flatter the DELTA Pro is only restating that $3,299 divided by $1,599 is 2.06, because the warranties are five years each. Nothing about the money is concealing a better buy. The money is buying watt-hours at the going rate.
$1,599 divided by 3,600Wh is $0.44 per watt-hour; $3,299 divided by 7,884.8Wh is $0.42Both units are rated 3,500 cyclesBoth carry a five-year warrantyLifetime energy works out to $0.13 per kWh for the DELTA Pro and $0.12 for the Apex
Why it mattersSkip the value comparison on this pair entirely and spend the decision on capacity and placement, which are the only two things that genuinely differ.
weight
The scenario table hands the Apex both Weekend Camping and Tailgate Party on percentage used, and those are precisely the two days that begin with loading the thing into a vehicle. Judged on energy it wins them. Judged on the trip it is the wrong shape, and the 99 lb wheeled box is the one that goes.
DELTA Pro: 99 lbs in a single chassis with integrated wheels and a telescoping handle, best on flat groundA2Apex 300 + B500K: 183 lbs across two boxes, the 2,764.8Wh Apex 300 and the 5,120Wh B500KOne reviewer could carry the Apex only a few feet at a time and could not lift it onto a tableB11The Apex switches to battery in 10ms and takes 2,400W of solar
Why it mattersIf the unit leaves the house more than a couple of times a year, read those two wins as scoreboard artefacts rather than advice.
The specific dimensions that decide these two units — everything else is a tie.
Your Life, Your Pick
Selected because: Five of six modelled days leave the DELTA Pro holding 960Wh or more in reserve, and one draws 4,685Wh and breaks it. This is where the decision actually happens.
The scoreboard says the Apex takes all six, and five of those six are the same finding restated: a bigger battery uses a smaller share of itself. On Weekend Camping, the 8-Hour Blackout, CPAP Overnight, Remote Workday and Tailgate Party, both units finish with energy left over. Only Van Life Daily separates them, and it separates them completely. 4,685Wh of draw against 3,060Wh usable is not a near miss, it is a different product class.
Two of the five ties-in-all-but-name deserve a further discount. Weekend Camping and Tailgate Party both begin with putting the unit in a vehicle, and one of these units is 183 lbs arriving in two pieces. The engine scores energy. It has no column for logistics.
Lifetime Value
Selected because: 44 cents a watt-hour against 42, on hardware with the same 3,500-cycle rating and the same five-year warranty. Worth showing precisely because it settles nothing.
cost / lifetime kWh
Two cents a watt-hour is the whole value story, and it runs the direction people don't expect: the expensive unit is fractionally the cheaper energy. Across the rated 3,500 cycles that comes out at $0.12 per kWh against $0.13, on warranties of the same five years. Whatever else divides these two, it is not which one is a better deal per unit of stored energy.
Which means the $1,700 does exactly one thing: it buys 4,284.8Wh more battery (7,884.8 minus 3,600). If you will use that, it is fairly priced. If you won't, there is no hidden efficiency, longevity or coverage advantage waiting to justify it. This is the rare pair where the cheaper answer isn't a compromise, it's just a smaller answer.
Portability & Form Factor
Selected because: 99 lbs in one wheeled shell against 183 lbs arriving as two boxes, which is the difference between a unit you pack and a unit you install.
weight
The DELTA Pro's 99 lbs is still a two-hands, bent-knees lift into a trunk, but once it's down it rolls on its own wheels and telescoping handle. That holds on driveways and campground pavement and stops holding on grass and gravel, where a cart starts to be necessaryA2.
The Apex's 183 lbs is a different kind of number, and reading it as a lift is the mistake. It is the sum of two boxes, the 2,764.8Wh Apex 300 and the 5,120Wh B500K, so you carry them one at a time and the real question is where the pair is going to live. One reviewer managed only a few feet per trip and couldn't get it onto a tableB11. Choose the spot, run the cables, and plan on it staying there.
What the Specs Don't Tell You
Selected because: Four cards fire here and two need reading carefully: the 183 lb figure is a two-box total, and both warranties are five years.
rated cycles
Read the weight card as a system total rather than a lift. 183 lbs is the two boxes together, and they arrive and move one at a time, so the number describes an installation rather than a carry.
The warranty card is the other one to read slowly. Both units carry five years, so length is a wash and should not move your decision. Any figure expressing coverage per dollar is measuring the price gap instead: $3,299 against $1,599 is 2.06 times, and dividing one identical warranty by two different prices reproduces exactly that. On transfer speed the difference is real but small, 10ms against 20ms, both inside what a desktop, a router or a CPAP rides through without noticing.
Brand Trust
Selected because: Support is the one place these brands truly diverge, and it matters more on the box you cannot carry back to a store.
EcoFlow's advantage is reachability: a US phone line, email and chat, plus the largest owner community in the category if the official route stalls. The record is polarized rather than uniformly good, with painless prepaid-label replacements at one end and long waits and refurbished units against new claims at the other, so this is a better-odds argument, not a guarantee.
BLUETTI's own profile names support consistency as its number one risk, and the channel is mostly email across a timezone gap. That is survivable on a unit you can box up and send back. It is a different proposition on a two-box system already wired into a corner of the house, particularly given the firmware trouble owners have hit on the ApexB7B9.
Strengths & trade-offs
EcoFlow DELTA Pro
Strengths
- +Costs $1,400 less
- +Lighter by 84 lb
Trade-offs
- –Very heavy unit that may be difficult for one person to lift.
- –Can receive complaints about fan noise under heavy load.
- –Shorter-lived battery — rated for 3,500 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 (+$1,400) than the DELTA Pro.
- –Significantly heavier (+84 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 Pro
The Apex ends the weekend at 31% used against the DELTA Pro's 69%, and both of those are comfortable numbers. A 2,100Wh weekend still leaves the DELTA Pro 960Wh in hand, close to half the trip's entire draw sitting unused. The Apex's margin is real, it is just insurance stacked on insurance, and it costs you 183 lbs in two boxes to bring to a campsite.
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 the evening puts the Apex at 25% used and the DELTA Pro at 54%, and the Apex's reserve is genuinely large: about 32.5 hours of the same load (6,702 divided by 1,645, times 8), or four full outage nights. The DELTA Pro manages about 15 hours, which covers the night and stops just short of a second one. If your outages run long or arrive in clusters, that is the gap that matters.
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
Apex 300 + B500K
A CPAP pulls about 40W, so 320Wh across eight hours: 5% of the Apex's usable bank against 10% of the DELTA Pro's. The Apex wins the percentage and the percentage is a formality, because both run this load for several nights without seeing a plug. At a draw this small neither unit is anywhere near its rated fan noise either, so decide this one on where the box has to sit and what it costs to put it there.
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 of laptop, monitor and phones leaves the Apex at 14% and the DELTA Pro at 30%. In plain energy that is 2,150Wh still in the DELTA Pro at close of business, more than two additional full workdays before it needs a plug. The Apex's margin is the bigger one and both are far past sufficient, so this scenario is a formality either way.
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 Pro
670Wh of speakers, a blender and a griddle barely registers on either bank: 10% used on the Apex, 22% on the DELTA Pro. Capacity is not what decides a tailgate. The DELTA Pro travels as one 99 lb wheeled box, while the Apex's 183 lbs arrives as two separate units to unload and set up. The Apex wins the number; the DELTA Pro wins the 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
This is the scenario that actually separates them. A 4,685Wh day needs more than the DELTA Pro has: 3,060Wh usable, short by 1,625Wh, and no amount of careful rationing closes a gap that size. The Apex finishes at 70% used with 2,017Wh still in reserve, and its 2,400W solar ceiling can put the whole day back before sundown. For full-time off-grid living this isn't a preference, it is the only one of the two that works.
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 14.9h.
$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 Pro
Take the DELTA Pro and keep the $1,700 unless you can name a day that draws more than 3,060Wh. It clears the modelled 8-hour outage (1,645Wh) with 1,415Wh still in the tank, carries a 2,100Wh camping weekend with 960Wh spare, and rolls to where you need it on its own wheels and telescoping handleA2. The Apex 300 + B500K is not overpriced. At 42 cents a watt-hour ($3,299 divided by 7,884.8Wh) against the DELTA Pro's 44 ($1,599 divided by 3,600Wh) it is marginally the better rate, and its 6,702Wh usable is the only bank here that covers a 4,685Wh off-grid day. But it is a two-box, 183 lb installation from a brand whose own profile names support consistency as its number one risk, and five of the six modelled days never touch the capacity you paid for. Buy it when your load has already outgrown the smaller box, not in case it might.
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.
$1,899.00 · 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, Solar Generator.
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 rates 3.9/5 (33rd percentile of 16 Home Backup-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.
What 183 lbs Actually Means
The Apex 300 + B500K's 183 lbs is a system total, not a lift. It arrives as two boxes, the 2,764.8Wh Apex 300 and the 5,120Wh B500K, so you move them separately and then choose where the stack lives. That makes it a placement decision rather than a carrying one. The DELTA Pro's 99 lbs is a single shell, and it rolls: wheels and a telescoping handle do the work on flat ground, hands and knees do it into a trunk. Ask where each unit will sit, not which number is bigger.
45dBA vs 60dBA, and When You'd Hear It
Both figures are ratings under load rather than what the unit does idling. 45dBA for the Apex against 60dBA for the DELTA Pro is a wide enough gap to matter in a bedroom or a small tent when either one is working hard. At light draws, a CPAP at about 40W, a laptop, a router, neither unit is near its rating. So weigh your heaviest sustained load and how close you sleep to it, not the two numbers on their own.
10ms vs 20ms: Real, Small
Both transfer times sit inside what a desktop, a router, a NAS or a CPAP will ride through without blinking, so 10ms against 20ms is not by itself a reason to pick one over the other for ordinary always-on gear. Where it begins to count is a permanently wired installation running sensitive equipment continuously, which is the shape the Apex is built for anyway.
Warranty: Five Years Each
Both units carry five years, so coverage length is a wash and shouldn't move your decision. Any years-per-dollar figure here is the price difference in disguise: $3,299 against $1,599 is 2.06 times, and dividing one identical warranty by two different prices reproduces exactly that ratio. What actually differs is not the length of the promise but how easily each company picks up the phone.
Battery Lifespan in Real Years
The Apex 300 + B500K is rated for 6,000 cycles vs 3,500. In real life: at daily use, that's 16.4 vs 9.6 years. At weekend use (twice a week), it's 58 vs 34 years. One caution reading years across different sizes: a cycle is 7,885Wh on the Apex 300 + B500K and 3,600Wh on the DELTA Pro, so count lifetime energy — roughly 47,309 kWh against 12,600 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 Pro.
Check DELTA Pro 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 Pro is cheaper to buy, but the Apex 300 + B500K is cheaper to own. At $0.07/kWh over its lifetime vs $0.15/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
Support is where these two brands genuinely diverge, and the stakes are not symmetrical. EcoFlow answers a US phone line and backs it with the largest owner community in the category, though the experience is polarized: painless prepaid-label swaps at one end, long waits and refurbished units against new claims at the other. BLUETTI's own weak point is support consistency, mostly email and across a timezone gap, with outcomes that vary by who picks up the ticket. A support miss on a $1,599 unit you can box up is an annoyance. On a two-box system already commissioned into a corner of the house, it is the difference between backup and furniture.
Growth path
DELTA Pro
EXPANDABLESupports EcoFlow expansion batteries, so you can add capacity later without replacing the base unit — useful if your needs may climb past 3,600Wh.
Accepts up to 1,600W of solar. Enough for a serious multi-panel array.
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 1,600W) 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
The DELTA Pro's field record is long and boring in the best way. It has served as primary home backup across repeated overnight outages, running fridge, lighting and heat together, and held up over months of thatA1A3. The knock is consistent and specific: above roughly 2,000W of draw the fans take on a high-pitched whine that is hard to ignore in a quiet room, though it stays civil at lighter loadsA4.
One caution about that record. Much of the available commentary blends the original DELTA Pro with the newer, heavier DELTA Pro 3, so any measured weight or decibel figure quoted in a review belongs to whichever unit that reviewer had. What carries across the line is what we lean on here: wheeled portability that works best on flat ground, home-backup focus, and fan noise under heavy loadA2A4.
“Long regarded as a gold standard for home backup — designed for high-draw appliances and full-scale battery expansion, running home essentials like a fridge, lighting, and a space heater through outages.”
Sources
backuppowerhub.com · us.ecoflow.co · outdoorgearlab.com · bobvila.com · powerstationadvisor.com · robbsutton.com
BLUETTI Apex 300 + B500K
Reviewers agree on one thing about the Apex: for its output class the fans are unusually even, with no whine or rattle, quiet enough to sit near a bed or a deskB1B2B13. Owners are less unanimous about the software. Firmware and app updates have locked units into Backup mode, failed mid-download, and in one case ended in an E004 inverter output errorB7B8B9, with several of those threads resolving after a later update or a round with supportB8B10.
Two more things to know before committing. Owners running multiple Apex units in parallel report them charging from the grid at different rates rather than in step, with a community-devised workaround rather than an official fixB3B4. And the field data for this exact 7,884.8Wh pairing is effectively absent: almost everything findable covers the bare Apex 300 or the B300K combo, a fair amount of it press loans rather than long-term ownershipB5B11. Nobody can yet tell you how this configuration behaves in year three.
“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
- Established home-backup platform with wheeled portability and massive expandability; the consistent knock is fan noise under heavy load. [DELTA Pro · 3 entries]
- 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
“Long regarded as a gold standard for home backup — designed for high-draw appliances and full-scale battery expansion, running home essentials like a fridge, lighting, and a space heater through outages.”
backuppowerhub.com / us.ecoflow.com — EcoFlow DELTA Pro review · 2025-2026 · [positive]
- A2
“Heavy but wheeled — integrated wheels and a telescoping handle help move its considerable weight, though they work best on flat, smooth surfaces; a cart is needed for uneven ground.”
outdoorgearlab.com / bobvila.com — DELTA Pro-line review · 2025-2026 · [mixed]
- A3
“Reliable through extended outage use — served as primary backup across multiple overnight outages over months, powering essentials simultaneously; LFP battery rated for thousands of cycles and 10+ years of daily use.”
powerstationadvisor.com / robbsutton.com — DELTA Pro-line review · 2025-2026 · [positive]
- A4
“Not silent under heavy load — under 2000W-plus draws the fans emit a noticeable high-pitched whine that's distracting in a quiet room, though it runs quietly enough at lighter loads.”
outdoorgearlab.com — DELTA Pro-line noise testing · 2025-2026 · [negative]
- 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]
- 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]
- 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 Pro if you…
- →You want the fridge, the lights, the router and the furnace fan to stay up through an evening outage. That is 1,645Wh modelled, and the DELTA Pro finishes it with 1,415Wh still in reserve.
- →You camp a few weekends a year and the unit has to get from the garage to the car to the site. 99 lbs on wheelsA2 is the only one of these two making that trip without a second pair of hands.
- →Your measured daily draw sits under 3,000Wh and you would rather have the $1,700 than the headroom.
Buy the Apex 300 + B500K if you…
- →You live in the van or the cabin and spend something like 4,685Wh a day, every day. 6,702Wh usable is the only bank here that covers it, and 2,400W of solar puts the day back before the sun goes down.
- →You are installing rather than packing: a fixed spot, a run of cable, 10ms to battery for gear that should never notice the grid dropping.
- →You already know the load is growing and would rather start from 6,702Wh usable than 3,060Wh. Both units take expansion batteries, but the Apex starts the climb much further up.
If neither fits
If your night is a CPAP and a phone, that is 320Wh against 3,060Wh usable, about 10% of the smaller unit here. You are shopping two tiers too high. A 1kWh-class station runs the same night for a fraction of either price, and you can pick it up with one hand.
The Bottom Line
Take the DELTA Pro. Five of the six days we model leave it with reserve to spare, it rolls to where you need it on 99 lbs and its own wheels, and it does that for $1,599 while conceding nothing on cycle life or warranty length. The Apex 300 + B500K is the better machine in the way a bigger machine is, with 6,702Wh usable, 2,400W of solar and 10ms to battery, and at 42 cents a watt-hour it is honestly priced for all of it. It is simply answering a question most buyers landing on this pair are not asking.
The question it does answer is the 4,685Wh day, and there it isn't close: the DELTA Pro is 1,625Wh short, and no amount of frugality closes a gap that size. So this is a measurement, not a preference. Clear 3,060Wh in a real day and buy the Apex, pick its spot before it arrives, and go in knowing the long-term field record for this exact pairing doesn't exist yetB5B11. Stay under it and buy the DELTA Pro with $1,700 still in your pocket.
Frequently Asked Questions
Answers drawn from the spec record and cited owner research.
Is the BLUETTI Apex 300 + B500K worth twice the price of the EcoFlow DELTA Pro?
Only if you will actually use the capacity. It costs 2.06 times as much ($3,299 against $1,599) for 2.19 times the energy (7,884.8Wh against 3,600Wh), so per watt-hour it is the slightly cheaper of the two, 42 cents against 44. That makes it fairly priced rather than a bargain. If your daily draw stays under the DELTA Pro's 3,060Wh usable, the extra $1,700 buys storage you never discharge.
How long will the EcoFlow DELTA Pro run my house in a blackout?
On the load we model for an 8-hour outage, 1,645Wh of fridge, lights and small electronics, the DELTA Pro's 3,060Wh usable covers about 15 hours (3,060 divided by 1,645, times 8). The Apex 300 + B500K's 6,702Wh stretches the same load to roughly 32.5 hours. Both clear one night comfortably; the DELTA Pro stops just short of a second, while the Apex clears four.
Which is quieter, the DELTA Pro or the Apex 300?
The Apex, on the rating and in reviews: 45dBA against the DELTA Pro's 60dBA, with reviewers describing its fans as even and free of whine or rattle. Bear in mind those are figures under load. At a CPAP-sized 40W draw (320Wh across eight hours) neither unit is working hard, and the DELTA Pro's noise complaint specifically appears above roughly 2,000W. If the unit sleeps in the bedroom and also runs heavy daytime loads, the Apex is the safer choice.
How heavy is the BLUETTI Apex 300 + B500K, really?
183 lbs, but that is the total for two separate boxes: the 2,764.8Wh Apex 300 and the 5,120Wh B500K that makes up the rest of the 7,884.8Wh. You move them one at a time, and even so, one reviewer managed only a few feet per trip and couldn't lift it onto a table. The DELTA Pro is 99 lbs in a single shell with wheels and a telescoping handle, which works well on flat ground and wants a cart on rough ground.
Can I buy the DELTA Pro now and add capacity later?
Yes, both units accept expansion batteries, so neither is a sealed ceiling. The catch is that expansion packs are a separate purchase at a price this comparison doesn't cover, so judge these two as configured: 3,600Wh for $1,599 or 7,884.8Wh for $3,299. If you already know you need the bigger bank, buying it once is simpler. If you are guessing, start smaller and let the meter decide.
Brand matchup
EcoFlow vs BLUETTI: measured across every matchup →Where to buy
EcoFlow DELTA ProPick
$1,899.00
$1,899.00 · 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.