Head-to-head test
EcoFlow DELTA Pro Ultra + 2 Batteries vs DJI Power 500
The decision isn't which box is better, it's whether your load list lives in one room or rides in your trunk: 18,432Wh sited at 405.4 lbs against 512Wh you pick up with one hand.
Full profiles: EcoFlow DELTA Pro Ultra + 2 Batteries → · DJI Power 500 →
Written by Gunner GustafsonUpdated
Whole-Home Backup Tester, Station Arena Test Desk
$7,999.00 · direct from EcoFlow
Last checked 8 hours ago. Prices move — check before you buy.
$299.00 · direct from DJI
Last checked 8 hours ago. Prices move — check before you buy.
Spec deltas
Thirty-six times the battery for twenty-seven times the money: 18,432Wh at $7,999 against 512Wh at $299. That ratio is the least useful thing on this page. One of these is hardware you site and the other is hardware you carry, and no amount of dividing turns one into a smaller version of the other.
Run them through our six load benches and the split goes one way on energy and the other way on logistics. The Ultra covers every bench, finishing an eight-hour blackout with 14,022Wh untouched. The Power 500 covers one, the CPAP night, and comes up 1,210Wh short of that same blackout and 4,250Wh short of a van-life day. What it is never short on is watts. It starts and holds every peak these scenarios ask for.
So the verdict is the Ultra, at moderate confidence, and the more useful sentence is this one: most people reading this should buy neither. If your real number is a camping weekend or a fridge through a storm, the 500 doesn't finish and the Ultra is a construction project. This page has answers at the two ends and nothing in the middle.
What the Numbers Reveal
Each conclusion stated first — the numbers behind it on one line, the full analysis below.
rated cycles
That only pays out if the cycles get used. At 3,500 cycles the Ultra's rated life is about 9.6 years of daily cycling, and someone installing 405.4 lbs in a utility room is usually buying insurance rather than a daily tool. For that buyer the honest metric flips to cost per warranty year, where it reads $800 against the Power 500's $60.
$7,999 for 18,432Wh rated to at least 3,500 cycles$299 for 512Wh rated to 4,000 cycleslifetime energy comes to 64,512 kWh for the Ultra against 2,048 kWh for the Power 500
Why it mattersIf the Ultra will sit near full waiting for an outage, stop using the per-kilowatt-hour figure to justify it and justify it the way you'd justify any insurance, by what the outage costs you.
So the spec to check before buying it is watt-hours, and the derate is unforgiving: 512Wh of nameplate is 435Wh of usable energy on the flat 85% factor our benches apply to every unit. That is one CPAP night, or about half a workday, and not both.
the Power 500 starts and sustains every peak across our six benches, including the 400W tailgate peakit still misses five of those six on energy: 1,665Wh short of the camping weekend, 1,210Wh of the blackout, 475Wh of the workday, 235Wh of the tailgate, 4,250Wh of the van-life dayreviewers ran a 905W load through it and watched it briefly take a 1,500W spike past its 1,000W ratingB3
Why it mattersAdd up the watt-hours of what you want to run and for how long before you buy the 500. If the total is over 435Wh, no amount of inverter headroom fixes it.
And the spot you choose is close to permanent, which makes one more field report worth its weight. An owner measured interference on 146.520MHz with the inverter not even running, and support suggested a Faraday cageA3A4. Whatever else lives in that room lives with it.
405.4 lbs in total, and the catalogue flags the Ultra as hardware you site rather than carrya reviewer's component breakdown puts the inverter at 71 lbs and each extra battery at 115 lbs, two people per boxA8one reviewer's install ran about nine hours of an electrician's time and included cutting drywall to sink the panelA17, after a hunt to find someone locally who had worked with this kind of gearA16
Why it mattersPick the room and check the floor before the boxes arrive, and if you run radio gear or anything sensitive nearby, choose that spot very deliberately.
The specific dimensions that decide these two units — everything else is a tie.
Your Life, Your Pick
Selected because: Six real load lists sort this pair faster than any spec row: the Power 500 clears one of them, the Ultra clears all six on energy.
The Power 500 loses these rows on energy while passing every peak, and the Ultra passes on energy while failing to show up. Two benches come back 'neither' for exactly that reason. A tailgate and a camping weekend need the box to arrive, and 405.4 lbs doesn't.
The useful read is where each one stops. The 500 quits around lunch on a workday and partway into an evening outage. The Ultra finishes the heaviest bench here, a 4,685Wh van-life day, having spent just under a third of its usable energy. There is no row in between where these two actually compete, which is the finding: this is a fork, not a comparison.
Portability & Form Factor
Selected because: 405.4 lbs that gets sited once against 16.1 lbs that rides in the passenger seat is the actual decision on this page.
weight
The Ultra's 405.4 lbs is not a lifting problem, it's an address. The total is spread across an inverter and its battery packs, which is the only reason it is movable at all, and then it goes into a garage or a utility room and stays. The second pair of hands on setup day is a line item, not a footnote.
The 500 sits at the other extreme and earns it: 16.1 lbs, one hand, passenger seat. The catch is hiding in what makes it portable. It has no built-in solar charge controller, so sun charging runs through a separate proprietary adapter, and it ships with a wall plug and nothing elseB4. The unit that travels is also the one you have to finish buying.
Lifetime Value
Selected because: Across its rated life the $7,999 system delivers energy at a lower cost per kilowatt-hour than the $299 one, which is either its best argument or a trap, depending on how often you cycle it.
cost / lifetime kWh
The counterintuitive number here is that the $7,999 system sells energy more cheaply than the $299 one does, at $0.12 a lifetime kilowatt-hour against $0.15, because 18,432Wh multiplied by at least 3,500 cycles is an enormous pile of kilowatt-hours.
Read it with the condition attached. That figure assumes the cycles get spent, and cost per warranty year tells the other half of the story: $800 a year for the Ultra against $60 for the Power 500. If the plan is daily off-grid living or shaving peak hours, the per-kilowatt-hour figure is the true one. If the plan is a box waiting in a corner for a storm, the per-year figure is.
What the Specs Don't Tell You
Selected because: Five cards fire on this pair, and four of them are about what you live with after the purchase: weight, surge headroom, UPS class and who is still covered in year six.
rated cycles
Five cards fire and only one is about capability. The rest describe the years after the purchase: what the weight commits you to, what the surge figures actually mean, which UPS class you're getting, and who is still covered in year six.
Two of them deserve a straight reading. The Power 500 publishes no surge figure above its 1,000W continuous rating, and that is the documented ceiling rather than a missing spec. Reviewers have watched it hold a brief spike past itB3. The Ultra's UPS figure is the maker's no-break classification rather than a measured time, and the 500's 20ms is a rating too. Neither came off a stopwatch, so neither should decide which one you buy.
Brand Trust
Selected because: Two very different track records, and they matter unevenly: EcoFlow's deep power-station ecosystem against DJI's 2024 arrival from drones weighs far more on a 10-year install than on a $299 box.
EcoFlow has the deepest ecosystem in portable power and the more mixed service record. DJI arrived in power stations in 2024 with a repair network built for drones and no power-station community to speak of. On a $299 unit that asymmetry barely registers. On a system you bolt into a utility room for a decade, it is part of what you are buying.
Two specifics do the work. EcoFlow sells no parts and no service once the warranty is up, which casts a long shadow across a 10-year install. And the sharp end of its support reputation turns up in this very ledger: the owner asking about a missing manual was pointed back at the web guide twice, and the one reporting radio interference was told he could put the unit in a Faraday cageA2A4. Neither is fatal. Both are worth knowing before you commit a room.
Strengths & trade-offs
EcoFlow DELTA Pro Ultra + 2 Batteries
Strengths
- +Larger battery capacity
- +Higher AC output
- +Longer warranty
- +Faster solar charging
Trade-offs
- –Substantially more expensive (+$7,700) than the Power 500.
- –Significantly heavier (+389.3 lbs), making it harder to move.
- –Very heavy unit that may be difficult for one person to lift.
DJI Power 500
Strengths
- +Costs $7,700 less
- +Lighter by 389.3 lb
Trade-offs
- –Weaker inverter (-6,200W) limits appliance compatibility.
- –Sealed capacity — the DELTA Pro Ultra + 2 Batteries can add batteries to grow past 512Wh; this one can't.
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
Nobody wins a weekend here. The bench asks for 2,100Wh across the trip, and the Power 500 covers about a fifth of it before quitting 1,665Wh short. The Ultra has the energy sitting right there and weighs 405.4 lbs, so it isn't coming to the campsite. If the trip is the point, this row is telling you to shop a mid-size portable instead of either of these.
Battery budget usedlower = more headroom
LOAD Phone Charger 15W×6h · LED Lights 40W×8h · Box Fan 75W×14h · CPAP Machine 40W×16h
SCN-02 · 8 hours · needs 1,645Wh
8-Hour Blackout
Keep the essentials running through a night without power
DELTA Pro Ultra + 2 Batteries
Eight hours of a real house comes to 1,645Wh, and the Power 500 taps out 1,210Wh from the far side of it, roughly a quarter of the night covered. The Ultra ends the same outage with 14,022Wh unused, which is the figure that says what it is actually for: not this outage, the three-day one. Outages don't schedule themselves, and a unit that covers part of one tends to cover the wrong part.
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
Power 500
A CPAP is about 40W, so 320Wh over eight hours is a night neither battery notices. The furniture decides this one. The Power 500 is 16.1 lbs on the nightstand and it comes with you to the hotel; the Ultra gets sited once and stays put, and you do not commission 405.4 lbs of hardware for a 40W load. Published noise ratings won't break the tie either way, because the makers don't measure the same way. Take the 500, and if you want two nights without a recharge, do the arithmetic first: 320Wh twice over is more than it holds usable.
Battery budget usedlower = more headroom
LOAD CPAP Machine 40W×8h
SCN-04 · 8 hours · needs 910Wh
Remote Workday
Full work day off-grid without power anxiety
DELTA Pro Ultra + 2 Batteries
A 910Wh workday is where the Power 500's size stops being charming. Its 435Wh of usable energy takes you to roughly lunch, 475Wh short of clocking out. The Ultra runs the same day on 6% of what it is holding. If you work remote from one place, that asymmetry is the entire argument; if you work remote from a different place every week, neither of these numbers saves you.
Battery budget usedlower = more headroom
LOAD Laptop 60W×8h · External Monitor 30W×8h · Router + Modem 20W×8h · Phone Charger 15W×2h
SCN-05 · 4 hours · needs 670Wh
Tailgate Party
Game day power for the crew
Neither unit
The 400W peak this bench asks for is nothing to either inverter. Both start it and hold it. The problem is the tank and the trunk: the Power 500 covers about 65% of the 670Wh a game day needs and quits 235Wh from the end, and the Ultra is not something you carry to a parking lot. Watts are easy. Watt-hours and wheels are not.
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
DELTA Pro Ultra + 2 Batteries
Only one of these covers a 4,685Wh day, and the Ultra does it having spent just under a third of its usable bank, while the Power 500 covers about 9% and lands 4,250Wh short. The catch is payload. Putting 405.4 lbs of hardware into a van is a build rather than a purchase, so read this row as a win for the Ultra and a warning about what the win costs.
Battery budget usedlower = more headroom
LOAD Mini-Fridge 150W×24h · Laptop 60W×4h · Phone Charger 15W×3h · LED Lights 40W×5h · Fan 75W×8h
The Load Test
RUNTIME = (Wh × 0.85) ÷ LOAD
None of the scenarios above exactly yours? Build it. Toggle what you'd plug in; both units are tested against the combined draw.
Essentials
Comfort & Convenience
High-Draw Appliances
Test duration
8h
Continuous draw
205W
Projected runtime
For this load: DELTA Pro Ultra + 2 Batteries runs 76.4h vs 2.1h.
$7,999 list · direct from EcoFlow
Modeled from the spec record — same math as the tables below. Methodology
Runtime by appliance
Real-world runtime estimates for common appliances, modeled at 85% inverter efficiency.¹
Essentials
The basics you need runningscale 0–1044.5hComfort & Convenience
Makes off-grid life actually enjoyablescale 0–208.9hHigh-Draw Appliances
These reveal the real limitsscale 0–15.7h¹ 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
September 13, 2026
Verdict: the DELTA Pro Ultra + 2 Batteries, on Power Score margin
Take the DELTA Pro Ultra with two extra batteries if the job is a building. It covers all six of our load benches on energy, ending an eight-hour blackout with 14,022Wh still unspent and a 4,685Wh van-life day at under a third of its usable bank, and it can grow past 18,432Wh if your needs climb. The Power 500 clears exactly one bench, the CPAP night, and clears it well. So the reversal is clean rather than a hedge: if everything you need to run fits inside 435Wh of usable energy and has to travel, buy the 500 and keep the $7,700 that separates $299 from $7,999. If your list is a fridge, a well pump and the lights, the 500 isn't a cheaper version of the Ultra. It's a different appliance that runs out before midnight. Confidence sits at moderate for one reason: the Ultra wins the comparison the page is asking, and most people who land here should buy neither of these.
Editor-assigned confidence, based on cited owner research and spec analysis.
List prices as of September 13, 2026. The links below open EcoFlow's and DJI's current prices.
$7,999.00 · direct from EcoFlow
Last checked 8 hours ago. Prices move — check before you buy.
or check the Power 500 price$299.00 list
Written by Gunner Gustafson, Whole-Home Backup Tester · Station Arena Test Desk · Updated September 13, 2026
Measured Data
Benchmark scores and the full spec record, side by side.
Benchmark scores
Not rated for both units (minimum threshold unmet): UPS, Home Backup, CPAP, Solar Generator, Tailgating, Food Truck, Apartment Balcony, Camping.
Full specifications
ᵈ Derived: price ÷ rated capacity. See the data behind our comparisons →
Comparison ToolAdd more power stations, side by sideOpen Tool →How these numbers are produced
Numeric verification
Every figure on this page traces to our spec database or arithmetic on it — no estimated numbers.
Owner claims
Statements about owner experience are cited to published reviews — see Sources & Research Notes below.
Runtime model
Runtime = (rated capacity × 0.85 inverter efficiency) ÷ device wattage. Solar recharge estimates assume panels deliver 70% of rated output. Cold weather, battery age, and stacked loads reduce real-world results.
Power Score
Computed from 14 published spec dimensions, weighted per use-case bench. Higher is better; a unit must meet a bench's minimum threshold to be rated.
See the full weight table and data sourcing on our methodology page →Class ranking (the star rating)
Each unit's star score is a category ranking, not customer reviews — no buyer opinions feed it. We score every station on size-independent quality (value, output, portability, endurance, ports, warranty, and more), then percentile-rank it against the other units in its capacity class, so a class-leading compact unit and a class-leading whole-home unit can both earn 5★. Here, DELTA Pro Ultra + 2 Batteries rates 3.8/5 (29th percentile of 29 Whole-Home / Off-Grid-class units), and Power 500 rates 4.6/5 (74th percentile of 20 Compact-class units).
How the class ranking is computed →Test Notes & Caveats
Hidden gotchas and advantages we spotted that you won't find on the product page.
405.4 lbs Is a Floor Plan, Not a Lift
No single box is the problem here. The total is spread across an inverter and its battery packs, and that is exactly why this is a siting decision rather than a carrying one. You pick a room with a solid floor, get a second pair of hands in once, and then you stop moving it. Choose the spot before you buy, because this is the only unit on the page whose weight shows up as a question about your house.
Sealed at 512Wh, and the Growth Path Isn't Free Either
A fixed 512Wh is only a flaw if you guessed low, and DJI put battery expansion on its bigger models rather than this one, so the number you buy is the number you keep. Size it to a real list instead of a hope. The honest flip side for the unit we picked: the Ultra's growth path is genuine, and every step of it is another heavy box in the same room and another line on the invoice.
Two Ceilings, Not Two Grades of Inverter
The Ultra publishes 10,800W of peak against 7,200W of continuous output, a 1.5x margin. The Power 500 publishes one number, 1,000W, and that single figure is its documented ceiling rather than a hole in the datasheet. Neither clears the 2x headroom people quote as a rule of thumb for motor startups, so read both at face value: the 400W peak on our tailgate bench sits comfortably inside either one, and anything with a serious motor belongs on the 7,200W side of the page.
One Is Rated No-Break, One Is Rated 20ms
The Ultra's UPS spec is the maker's no-break classification, not a stopwatch reading, so treat it as a design claim rather than a measured gap. The Power 500 is rated at 20ms or better, which routers, modems and most electronics never notice. If the thing being protected is a desktop with unsaved work, the rated class is worth your attention. Neither figure is a lab result.
The Question Is Year Six
Ten years against five is trivia on a $299 purchase and close to the whole risk on a $7,999 one. The cheaper unit buys more warranty per dollar, which is a fact about its price rather than about its coverage. The test is simpler than the ratio: if a fault turns up in year six, one of these is a support ticket and the other is yours to solve.
Full record above — the Test Desk pick is the DELTA Pro Ultra + 2 Batteries.
Check DELTA Pro Ultra + 2 Batteries price →or check the Power 500 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 Power 500 is cheaper to buy, but the DELTA Pro Ultra + 2 Batteries is cheaper to own. At $0.12/kWh over its lifetime vs $0.15/kWh, the DELTA Pro Ultra + 2 Batteries's higher cycle life and capacity make each dollar go further over the years. One caution on the lifespan row: the Power 500 takes longer to reach its cycle rating, but a cycle moves a different amount of energy on each unit — the DELTA Pro Ultra + 2 Batteries still delivers more over its shorter horizon (64,512 vs 2,048 kWh). Years measure wear, not usefulness.
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
EcoFlow answers the phone in the US and the outcomes vary widely: some claims close with a prepaid label and a quick replacement, others turn into long waits or a refurbished unit against a new fault. Buying through a retailer with its own returns desk is cheap insurance on a purchase this size.
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 sells no parts and no service once the warranty is up, which is a longer shadow on a 10-year install than on a unit you would have replaced anyway. Decide now how you feel about the second decade.
DJI
Ecosystem
New entrant (2024) — five power station models to date: Power 500, Power 1000 (since superseded by the V2 but still sold), Power 1000 V2, Power 1000 Mini, Power 2000. Buying a "Power 1000" listing? Check which revision it actually ships.
Support
Leveraging DJI's established global support and repair center network from the drone business. Generally positive reputation inherited from drone operations, but limited power-station-specific track record.
Community
There is no DJI power-station community yet. Questions land in a drone forum of a quarter-million people who mostly own drones, which is a thin place to go looking up an odd fault at 11pm.
App experience
Rated 3.5/5 iOS and Android (DJI Home app ratings reflect entire DJI ecosystem including drones/cameras, not power-station-specific). Users report the on-device screen is more reliable than the app.
Unique strength
Runs quiet — 23-30dB published on most of the range (manufacturer best-case figures), at the quiet end of the category; our record carries no figure for the Power 1000 V2. Fast wall charging, quickest on the Power 1000 V2 at ~56 min — that figure is the V2's, not the whole line's. 700+ battery patents from drone R&D. SDC ports for ultra-fast DJI drone charging. Premium industrial design and build quality. LFP batteries rated for 4,000+ cycles.
Worth knowing
DJI's power line arrived in 2024, so the long-term record simply isn't there, and the app rating you'll find covers the whole DJI ecosystem, drones included. The 500 also has no built-in solar charge controller, so charging from the sun runs through a separate proprietary adapter you have to buy on purpose.
Analyst note
A mature ecosystem against a new one, and the weight of that lands differently at each end of the price range. On a $299 box, a thin support record is a $299 risk. On a $7,999 system you are bolting into a utility room for a decade, ecosystem depth, panel compatibility and who picks up the phone in year seven are part of the product.
Growth path
DELTA Pro Ultra + 2 Batteries
EXPANDABLESupports EcoFlow expansion batteries, so you can add capacity later without replacing the base unit — useful if your needs may climb past 18,432Wh.
Accepts up to 5,600W of solar. Enough for a serious multi-panel array.
Adequate ports for most setups, but heavy users may want a power strip.
Expansion batteries are EcoFlow-specific. You're investing in the EcoFlow ecosystem.
Power 500
FIXED CAPACITYFixed at 512Wh, with no expansion — so size it for your needs up front rather than planning to add capacity later.
Accepts up to 300W of solar. Limited to a single portable panel.
Adequate ports for most setups, but heavy users may want a power strip.
Realistic full solar rechargeat 70% of rated panel output — see methodology
Analyst note
The Power 500 is sealed at 512Wh, which is fine if that covers you. The DELTA Pro Ultra + 2 Batteries starts at 18,432Wh and can grow beyond it with EcoFlow expansion batteries — real headroom the Power 500 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 Pro Ultra + 2 Batteries
Long-term evidence on this exact configuration is thin, and that belongs at the top. Most of the detailed criticism traces to a single DIY Solar Forum thread and a handful of short retail reviews, several of which say themselves that it is too early to speak to longevityA0. What is in that thread is specific, though. One owner came away flat on the whole system and unlikely to expand it or integrate it into the houseA1, found no real manual behind a web guide he called superficial and got pointed back at that same guide twice by supportA2, could find no state-of-charge graph in the appA5, and watched a pack he had charged to 90% read 8% after a few days of overnight useA6. A tester separately flags idle self-consumption as something you have to budget for off-gridA7. The strangest entry is the most useful if it applies to you: interference on 146.520MHz with the inverter not even running, answered with a suggestion to build a Faraday cageA3A4.
The two-battery owners are the happy ones. They describe a central air conditioner, a refrigerator and a well pump running at once without a flickerA9, most of a house carried through peak hoursA14, and one owner running two of these systems calls the scalability and the way it heats and cools itself the best part of itA10. Another says the second battery doubled his runtime and took the anxiety out of an outageA13. Two practical cautions come with that. The packs are dense, a reviewer's breakdown putting the inverter at 71 lbs and each extra battery at 115 lbs with two people needed per boxA8, and one owner found the battery nearest the inverter running about 10 degrees warmer than the one below it, in a garage that hits 98 degrees in summerA11A12. On noise, one reviewer says he never heard a fan at allA15, which is an impression rather than a measurement, and the published figure beside it is the maker's own rating.
“This means that without any grid or solar input, the system would fully drain its own 6kWh battery in about 60 hours. For off-grid use, this parasitic drain must be carefully factored into your energy budget.”
DJI Power 500
Field evidence on the Power 500 is reviewer evidence, not owner evidence: a light, efficient small unit popular with drone pilots, sourced from established review sites rather than from long-term useB0. What testing exists looks good. Reviewers ran a 905W load through it, saw it briefly take a 1,500W spike past its 1,000W rating, and found it more efficient than the larger DJI Power 1000B3. The cells are automotive-grade LFP rated in the 3,000 to 4,000 cycle range, which is roughly a decade of weekend-tool useB1, and at about 7.3 kg it is a one-hand carryB2. The one consistent complaint is the box contents: a wall plug and nothing else, no solar adapter and no car cableB4. Nobody has owned one long enough to tell you what year four looks like.
“A 512Wh LFP battery with up to 1,000W output; the automotive-grade LFP cells are rated up to 3,000-4,000 cycles for roughly a 10-year lifespan.”
Sources
dji.com · thesolarlab.com · techradar.com · views-sounds.com · t3.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
- Owners repeatedly report EcoFlow customer support gives dismissive or unhelpful answers to specific technical questions (manual gaps, RFI interference, app charting). [DELTA Pro Ultra + 2 Batteries · 3 entries]
- The unit's idle/parasitic self-consumption is a recurring theme, both as a documented SoC anomaly and as an acknowledged spec-level drain figure from a tester. [DELTA Pro Ultra + 2 Batteries · 2 entries]
- Multiple owners note the extra battery packs are extremely heavy (100+ lbs each), requiring two people, and one owner separately observed uneven heat between stacked batteries raising summer overheating concerns. [DELTA Pro Ultra + 2 Batteries · 3 entries]
- Real owners with 2-battery setups consistently praise seamless/flicker-free UPS switchover and confirm the system genuinely runs whole-home loads (AC, well pump, most of house). [DELTA Pro Ultra + 2 Batteries · 3 entries]
- Adding a second battery is described by owners as meaningfully extending real-world runtime for whole-home backup, matching expectations. [DELTA Pro Ultra + 2 Batteries · 2 entries]
- Light, efficient LFP unit with strong real-world output and drone-pilot appeal; the caveat is minimal included accessories. [Power 500 · 3 entries]
- A1
“Pulled the trigger on an EcoFlow Delta Pro Ultra (DPU) and I'm kind of meh on it and unlikely to expand or integrate it into the house.”
DIY Solar Power Forum — 'Ecoflow Delta Pro Ultra issues' thread · 2024-02 · [negative]
- A2
“No real manual. All they have is the web user guide which is superficial if I'm being generous. I asked support about it and they pointed me at the web guide I was complaining about. Twice.”
DIY Solar Power Forum — 'Ecoflow Delta Pro Ultra issues' thread · 2024-02 · [negative]
- A3
“Even when the inverter is not running, it interferes with common frequencies like 146.520MHz.”
DIY Solar Power Forum — 'Ecoflow Delta Pro Ultra issues' thread · 2024-02 · [negative]
- A4
“I contacted EcoFlow support and they told me I could put it in a 'faraday cage'.”
DIY Solar Power Forum — 'Ecoflow Delta Pro Ultra issues' thread · 2024-02 · [negative]
- A5
“No State of Charge graph in the app... I contacted support and twice they told me to go to the app screen with the charts, which only has input and output.”
DIY Solar Power Forum — 'Ecoflow Delta Pro Ultra issues' thread · 2024-02 · [negative]
- A6
“After a few days of using it overnight and letting it charge back up to '90%', it'd go from '90%' down to '8%'.”
DIY Solar Power Forum — 'Ecoflow Delta Pro Ultra issues' thread · 2024-02 · [negative]
- A7
“This means that without any grid or solar input, the system would fully drain its own 6kWh battery in about 60 hours. For off-grid use, this parasitic drain must be carefully factored into your energy budget.”
Battery Skills — 'EF ECOFLOW DELTA Pro Ultra + Extra Battery Review' · 2025-10 · [mixed]
- A8
“The main inverter is a manageable 71 lbs, but each Ultra Smart Extra Battery is a dense 115 lbs, requiring two people for safe movement.”
Battery Skills — 'EF ECOFLOW DELTA Pro Ultra + Extra Battery Review' · 2025-10 · [mixed]
- A9
“We powered a central air conditioner, refrigerator, and well pump simultaneously without a flicker.”
Battery Skills — 'EF ECOFLOW DELTA Pro Ultra + Extra Battery Review' · 2025-10 · [positive]
- A10
“I own two Delta Pro Ultra's with two batteries each... We have experienced matchless performance, scalability, flexibility. It cools/heats itself in temperature extremes-simply awesome!”
Walmart customer reviews — 'EF EcoFlow Extra Battery for DELTA Pro Ultra' · unknown · [positive]
- A11
“I noticed the battery closest to the inverter seems to run hotter than the one below. About 10 degrees warmer. I switched the batteries around to ensure that it wasn't the battery and got the same results.”
Walmart customer reviews — 'EF EcoFlow Extra Battery for DELTA Pro Ultra' · unknown · [negative]
- A12
“My garage could get up to 98 degrees during the summer, that means my batteries can overheat.”
Walmart customer reviews — 'EF EcoFlow Extra Battery for DELTA Pro Ultra' · unknown · [negative]
- A13
“I originally bought my Delta Pro Ultra with the single battery, worked great is able to power my entire home for about 4 to 5 hours during peak times... I bought a second battery... My run time has doubled eliminating the anxiety.”
Walmart customer reviews — 'EF EcoFlow Extra Battery for DELTA Pro Ultra' · unknown · [positive]
- A14
“With the home panel, there is no flicker when the power changes. I bought a unit with 2 batteries and it runs my most of my house.”
Walmart customer reviews — 'EF EcoFlow Extra Battery for DELTA Pro Ultra' · unknown · [positive]
- A15
“I was pleased to discover the DPU runs completely silent; if a fan kicked on at some point, I never heard it.”
Yahoo Tech — 'EcoFlow Delta Pro Ultra whole home battery backup review' · 2024-06 · [positive]
- A16
“In my neck of the woods (suburban Detroit), it was a bit challenging finding one who had experience with this kind of gear.”
Yahoo Tech — 'EcoFlow Delta Pro Ultra whole home battery backup review' · 2024-06 · [mixed]
- A17
“Sure enough, the job went smoothly; it took him around nine total hours to complete, which included cutting out portions of drywall in order to sink the panel into the wall.”
Yahoo Tech — 'EcoFlow Delta Pro Ultra whole home battery backup review' · 2024-06 · [mixed]
- B1
“A 512Wh LFP battery with up to 1,000W output; the automotive-grade LFP cells are rated up to 3,000-4,000 cycles for roughly a 10-year lifespan.”
dji.com / thesolarlab.com — Power 500 review · 2026 · [positive]
- B2
“Weighs only about 7.3 kg, making it easy to transport.”
dji.com / techradar.com — Power 500 review · 2026 · [positive]
- B3
“In testing it ran a 905W load and briefly handled a 1,500W surge above its 1,000W rating; reviewers found it outperformed the larger DJI Power 1000 in efficiency testing.”
thesolarlab.com / views-sounds.com — Power 500 review · 2026 · [positive]
- B4
“Reviews are positive overall, though one noted it ships with only a wall plug — no solar adapters or car-charging cables included.”
t3.com / techradar.com — Power 500 review · 2026 · [mixed]
Research compiled September 13, 2026.
Who Should Buy Which
Buy the DELTA Pro Ultra + 2 Batteries if you…
- →The homeowner whose outage list is the whole house: fridge, well pump, central air, the lights. Owners with two batteries describe exactly that, without a flickerA9A14, and our eight-hour bench ends with 14,022Wh still unspent.
- →Anyone already planning an electrician and a permanent spot in a garage or utility room, who would rather buy a system with somewhere to grow than a box to replace.
- →The buyer who will genuinely cycle it most days rather than leave it near full waiting for weather, because that is the only person for whom the cost-per-kilowatt-hour argument is a reason instead of a footnote.
Buy the Power 500 if you…
- →The drone and camera owner topping batteries up out of a trunk. It is a one-hand carryB2, and DJI's fast SDC ports only pay off for people already inside the DJI ecosystem, which is exactly who this is.
- →The CPAP user who wants the unit on the nightstand and in the hotel bag. A 320Wh night fits inside its 435Wh of usable energy with room left over. Two nights back to back, at 640Wh, do not.
- →Anyone who wants a first battery for $299 instead of a project: lights, phones, a laptop and a fan, on a shelf until the power goes out. Budget separately for the solar adapter and the car cable, because neither is in the boxB4.
If neither fits
If your real number sits in the middle, which is where most numbers sit, neither of these is your unit: the 2,100Wh camping weekend, the 1,645Wh blackout, the 4,685Wh van-life day. The Power 500 misses all three, and the Ultra answers them by becoming part of the building. Shop mid-size portables instead, sized to your actual watt-hour total rather than to the two extremes on this page. One box, two hands, no electrician.
The Bottom Line
Take the DELTA Pro Ultra with two extra batteries if the thing you are powering has an address. It is the only one of the two that finishes a blackout, a workday or a van-life day, and across its rated life it delivers energy at a lower cost per kilowatt-hour than the $299 box does, which is the least intuitive fact on this page and the most durable one. The bill for that is 405.4 lbs, a room you commit to, and a support desk that can be maddening about specificsA2A4A5.
Take the Power 500 if the load is small and has to move. It clears the CPAP night, it holds every peak our benches ask of it, and it does that at 16.1 lbs for $299. And if your number sits between these two, a storm, a fridge, a weekend, buy neither and buy the middle. Sizing a unit to the two extremes of a catalogue is how people end up with a box that can't finish or a box that can't come.
Frequently Asked Questions
Answers drawn from the spec record and cited owner research.
Can the DJI Power 500 get me through a blackout?
Part of one. Our eight-hour bench needs 1,645Wh and the Power 500 holds 435Wh of usable energy, so it covers about a quarter of the night and stops 1,210Wh short. At that bench's average draw of roughly 206W, which is 1,645Wh spread over eight hours, you get about two hours. Treat it as a way to keep phones, a router and a CPAP alive, not a way to keep a fridge cold.
Is the DELTA Pro Ultra + 2 Batteries worth $7,999 when $299 buys a power station?
They are not the same purchase. The $7,999 buys 18,432Wh, 7,200W of continuous output, 10,800W of peak, a 10-year warranty and room to expand; the $299 buys 512Wh you can carry. Per unit of energy across its rated life the Ultra is the cheaper of the two, but only if you cycle it, and the sticker is not the whole bill once a room and an electrician are in it. If you don't need whole-house loads, the $7,700 difference is better spent elsewhere.
Do I need an electrician for the DELTA Pro Ultra?
Not to use it, only to wire it into the house. There are three AC outlets, two 240V outlets and a 30A RV outlet on the box, so you can run cords off it like any large station. The whole-home path is the one that needs a trade: one reviewer's install took about nine hours and included cutting drywall to sink the panel, and finding an installer who had worked with this gear took some looking.
Which one is quieter to sleep next to?
The published numbers can't tell you. Both makers quote low figures but they don't measure the same way, some publishing a best case and some a figure under load, so the two aren't comparable and neither describes a 40W CPAP draw. One reviewer said he never heard the Ultra's fan at all, which is an impression rather than a measurement. If quiet at low load is your deciding factor, go looking for hands-on reports of the specific unit before you buy.
Can I add a battery to the DJI Power 500 later?
No. The Power 500 is sealed at 512Wh, and DJI put battery expansion on its larger models rather than this one, so size it up front. That isn't a flaw in a unit built to be small and carried; it's a reason to be honest about your watt-hour total before you pay. The Ultra is the opposite case, taking expansion batteries if your needs climb past 18,432Wh.
Brand matchup
EcoFlow vs DJI: measured across every matchup →Related comparisons
Where to buy
EcoFlow DELTA Pro Ultra + 2 BatteriesPick
$7,999.00
$7,999.00 · direct from EcoFlow
Last checked 8 hours ago. Prices move — check before you buy.
DJI Power 500
$299.00
$299.00 · direct from DJI
Last checked 8 hours ago. Prices move — check before you buy.
Prices may vary by retailer and are subject to change.