Head-to-head test
EcoFlow DELTA 3 Ultra vs BLUETTI Apex 300 + B500K
Real-world runtimes, scenario verdicts, and ownership costs compared — which wins for your use case.
Written by Gunner GustafsonUpdated
Whole-Home Backup Tester, Station Arena Test Desk
EcoFlow
DELTA 3 Ultra
5,450Power Score · The AC & Fridge Zone
$1,199.00 list · direct from EcoFlow
BLUETTI
Apex 300 + B500K
7,794Power Score · The AC & Fridge Zone
$3,199.00 list · direct from BLUETTI
Spec deltas
The EcoFlow DELTA 3 Ultra (3,072Wh) and BLUETTI Apex 300 + B500K (7,885Wh) sit in different weight classes. The real question: do your power needs justify the larger unit, or would you be overpaying for capacity that sits unused? The Apex 300 + B500K has a slight edge, but the margin is close enough that your use case should break the tie.
The Apex 300 + B500K holds 4,813Wh more than the DELTA 3 Ultra — about 45 hours on a fridge against 17 — a real but modest edge that shows up mainly on longer outages. For camping, tailgating, or keeping devices charged, both have the headroom, so price, weight, and longevity lead the decision instead.
Pick the Apex 300 + B500K if your primary use is weekend camping or 8-hour blackout. Go with the DELTA 3 Ultra if you want the option to add expansion batteries later. Most buyers stop at the sticker price and miss this: over a full lifespan the DELTA 3 Ultra works out to about $0.1/kWh against the Apex 300 + B500K's $0.12, a gap that compounds in the DELTA 3 Ultra's favor the more you cycle it. Keep scrolling for the full breakdown. The scenario verdicts below hold a few surprises.
Bench Notes
What each unit does well, where it falls short, and the trade-offs that matter.
EcoFlow DELTA 3 Ultra
With a massive 3,600W output (and 7,200W surge), the DELTA 3 Ultra can run high-wattage appliances like space heaters, hair dryers, and electric grills without tripping. Weighing in at 77.2 lbs, this is not a unit you want to carry far. It's best suited as a stationary backup or RV companion. A standout feature is the value proposition: at roughly $0.39 per watt-hour, it's one of the most cost-effective options on the market.
Strengths
- +Costs $2,000 less
- +Lighter by 105.8 lb
Trade-offs
- –No major technical downsides compared to rival.
BLUETTI Apex 300 + B500K
With a massive 3,840W output (and 7,680W surge), the Apex 300 + B500K can run high-wattage appliances like space heaters, hair dryers, and electric grills without tripping. Weighing in at 183 lbs, this is not a unit you want to carry far. It's best suited as a stationary backup or RV companion. A standout feature is the value proposition: at roughly $0.41 per watt-hour, it's one of the most cost-effective options on the market.
Strengths
- +Larger battery capacity
- +Higher AC output
- +Faster solar charging
Trade-offs
- –Substantially more expensive (+$2,000) than the DELTA 3 Ultra.
- –Significantly heavier (+105.8 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
Apex 300 + B500K
The DELTA 3 Ultra cuts it close at 80%. One cold night or an unexpected device and you're rationing power. The Apex 300 + B500K finishes at 31%, leaving real headroom for spontaneous use. If you camp in variable weather, that buffer keeps you relaxed instead of checking your battery app every 20 minutes.
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
Both survive, but the Apex 300 + B500K finishes at just 25% used. That's enough reserve for a second blackout night. The DELTA 3 Ultra at 63% leaves little margin if the outage runs longer than expected. In storm-prone areas, that remaining capacity is insurance.
Battery budget usedlower = more headroom
LOAD Fridge 150W×8h · Router + Modem 20W×8h · LED Lights (4 bulbs) 40W×6h · Phone Charger 15W×3h
SCN-03 · 8 hours · needs 320Wh
CPAP Overnight
Sleep therapy without interruption — the #1 medical use case
Either unit
Both are wildly overqualified for CPAP. You're using 12% or less. Save your money and buy whichever is cheaper; the extra capacity is completely wasted on a 40W overnight load. Put the savings toward a second battery for multi-night trips.
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
The Apex 300 + B500K gives you a comfortable buffer at 14%. Enough to work late, join extra video calls, or charge a second device without worry. The DELTA 3 Ultra at 35% works but leaves less room for the unexpected. For daily remote work, that peace of mind matters.
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
Apex 300 + B500K
Both handle it, but neither is stressed. Tailgating is a light load. The Apex 300 + B500K's extra margin is nice but not decisive here. Consider weight instead: you're carrying this to a parking lot, and 106 lbs makes a real difference when loading up.
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
The DELTA 3 Ultra runs out of juice. It only has 2,611Wh usable, but this scenario needs 4,685Wh. The Apex 300 + B500K covers it and still has 134h of phone charging left over.
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 six 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 12.7h.
$3,199 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
July 10, 2026
Verdict: the Apex 300 + B500K, on Power Score margin
These two units are closely matched on individual specs, but our Power Score analysis gives the Apex 300 + B500K the edge with a composite score of 7,794 vs 5,450.
Overall score margin: 5,450 vs 7,794 (−43.0%)
List prices as of July 10, 2026. The links below open EcoFlow's and BLUETTI's current prices.
$3,199.00 list · direct from BLUETTI
or check the DELTA 3 Ultra price$1,199.00 list
Written by Gunner Gustafson, Whole-Home Backup Tester · Station Arena Test Desk · Updated July 10, 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, Tailgating.
Full specifications
ᵈ Derived: price ÷ rated capacity. See the data behind our comparisons →
Comparison ToolAdd more power stations, side by sideOpen Tool →How these numbers are produced
Numeric verification
Every figure on this page traces to our spec database or arithmetic on it — no estimated numbers.
Owner claims
Statements about owner experience are cited to published reviews.
Runtime model
Runtime = (rated capacity × 0.85 inverter efficiency) ÷ device wattage. Solar recharge estimates assume panels deliver 70% of rated output. Cold weather, battery age, and stacked loads reduce real-world results.
Power Score
Computed from 14 published spec dimensions, weighted per use-case bench. Higher is better; a unit must meet a bench's minimum threshold to be rated.
See the full weight table and data sourcing on our methodology page →Class ranking (the star rating)
Each unit's star score is a category ranking, not customer reviews — no buyer opinions feed it. We score every station on size-independent quality (value, output, portability, endurance, ports, warranty, and more), then percentile-rank it against the other units in its capacity class, so a class-leading compact unit and a class-leading whole-home unit can both earn 5★. Here, DELTA 3 Ultra rates 5.0/5 (99th percentile of 25 Large-class units), and Apex 300 + B500K rates 3.6/5 (19th percentile of 17 Whole-Home / Off-Grid-class units).
How the class ranking is computed →Test Notes & Caveats
Hidden gotchas and advantages we spotted that you won't find on the product page.
Weight Reality Check
Neither unit is grab-and-go. The DELTA 3 Ultra (77.2 lbs) is manageable solo but heavier than a large checked suitcase. The Apex 300 + B500K (183 lbs) is firmly a two-person lift. It goes where you put it and stays there. That's a 106 lb difference, which you'll feel every time you relocate.
Apex 300 + B500K: 45dB Under Load
45dB is about as loud as a running refrigerator. If you're running a CPAP or sleeping near this unit, the fan noise may be noticeable. Most people find anything above 45dB disruptive for sleep.
Warranty Value Comparison
The DELTA 3 Ultra gives you 4.2 years of warranty per $1,000 spent, vs the Apex 300 + B500K's 1.6 years. That's 2.7× more coverage per dollar. An underrated factor if you're keeping this unit for years.
Full record above — the Test Desk pick is the Apex 300 + B500K.
Check Apex 300 + B500K price →or check the DELTA 3 Ultra 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
Both units have similar long-term ownership costs ($0.1/kWh vs $0.12/kWh). The price difference is what you see on the sticker — neither is a hidden bargain or rip-off.
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. Supports up to 180kWh modular expansion with DELTA Pro Ultra X.
Worth knowing
The Oct 2025 DELTA Max 2000 recall (overheating/fire risk, 6 incidents) is worth noting. Also 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 (Apex 300, 3072Wh). 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
Best capacity-to-price ratio in the market — strongest value proposition overall. Widest product diversity including industry-firsts like sodium-ion cold-weather units and dual solar+alternator vehicle hubs. Full LFP standardization across lineup (3,500-6,000+ cycles). 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 Ultra
EXPANDABLESupports EcoFlow expansion batteries, so you can add capacity later without replacing the base unit — useful if your needs may climb past 3,072Wh.
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.
The Bottom Line
The full picture comes down to this. The Apex 300 + B500K edges ahead on our overall analysis, but the margin is narrow enough that your specific use case should drive the decision. Review the scenario verdicts above — if the DELTA 3 Ultra wins in the scenarios that match your life, it's the right choice regardless of aggregate scores.
If neither the DELTA 3 Ultra nor the Apex 300 + B500K feels like the right fit, your power needs probably sit outside what these two target. For lighter use — weekend camping or phone/laptop charging — you'd be overpaying for capacity you'll rarely tap. Consider a unit in the 500–1,500Wh range instead. Prices on portable power stations fluctuate frequently. Both EcoFlow and BLUETTI discount regularly, so check the current price before committing. Prime Day and Black Friday pricing typically drops 20-30%.
Frequently Asked Questions
Answers drawn from the spec record and cited owner research.
Is the Apex 300 + B500K worth $2,000 more than the DELTA 3 Ultra?
The short answer: yes, if you'll actually use the extra capability. The Apex 300 + B500K costs $2,000 more, but that premium buys you 4,812.8Wh more battery capacity (that's 27 extra hours of running a mini-fridge); 800W faster solar charging for quicker off-grid recovery. On a cost-per-watt-hour basis, you're paying $0.41/Wh vs $0.39/Wh. For regular use, we'd pay the premium.
How does the 4,812.8Wh capacity difference actually affect daily use?
The Apex 300 + B500K's 7,884.8Wh battery keeps a mini-fridge running for roughly 45 hours vs the DELTA 3 Ultra's 17 hours. Both can handle a full 8-hour blackout setup (fridge + router + lights + phone charging ≈ 1,645Wh), but the Apex 300 + B500K finishes with significantly more margin. That matters if conditions aren't ideal or the outage runs long. What specs don't mention: runtime drops 20-30% in cold weather (below 32°F/0°C) as battery chemistry slows down. The Apex 300 + B500K's extra capacity provides a critical cold-weather buffer. For occasional phone and laptop charging, both are overkill. This gap only matters for sustained, multi-appliance use.
Can I actually carry the Apex 300 + B500K, or is the DELTA 3 Ultra the only portable option?
Neither is "portable" in any hiking sense. The DELTA 3 Ultra (77.2 lbs) and the Apex 300 + B500K (183 lbs) are both appliances you place and leave. The 105.8-lb difference matters when loading into a vehicle or moving between rooms, but that's about it. If true portability is your priority, look at units under 20 lbs in a different class entirely.
How fast can each unit recharge from solar panels in real conditions?
On paper, the Apex 300 + B500K accepts 2,400W vs the DELTA 3 Ultra's 1,600W of solar input. What the spec sheet won't tell you: solar panels typically deliver only 60-80% of their rated output due to panel angle, cloud cover, and temperature. In realistic conditions, expect full recharge in about 4.7 hours for the Apex 300 + B500K and 2.7 hours for the DELTA 3 Ultra. That gap widens on cloudy days, when the Apex 300 + B500K's higher input ceiling captures more of whatever sunlight is available. One more thing: summer gives you ~7 productive solar hours per day. Winter drops to ~4. If solar is your primary recharge method, the Apex 300 + B500K's advantage is substantial.
Is EcoFlow or BLUETTI more reliable for long-term ownership?
Both brands have strengths and trade-offs. EcoFlow: Mixed. 2-5 years depending on model (DELTA Pro Ultra line gets 10 years). Some users report smooth claims; others report runarounds. Register your product to extend coverage. BLUETTI: 2-6 years depending on model (up to 10 years on home backup systems). Response times vary significantly. Some reports of units being deemed unrepairable with no parts available for older models. One piece of advice from the power station community: regardless of brand, buy from Costco or Amazon. Their return policies provide a safety net that manufacturer warranties alone can't match, especially for a product you'll rely on in emergencies. Both brands use LFP (lithium iron phosphate) batteries in their current lineup, the most proven chemistry for longevity and safety.
Bottom line: should I buy the DELTA 3 Ultra or the Apex 300 + B500K?
We'd pay the premium for the Apex 300 + B500K. Yes, it costs more. The capability jump is real: you're stepping into a tier that handles appliances the base model can't start. The DELTA 3 Ultra is still solid if budget is the priority, but the Apex 300 + B500K will leave you less likely to wish you'd "gone bigger" six months from now. That regret costs more than the price difference.
Where to buy
EcoFlow DELTA 3 Ultra
$1,199.00
$1,199.00 list · direct from EcoFlow
BLUETTI Apex 300 + B500KPick
$3,199.00
$3,199.00 list · direct from BLUETTI
Prices may vary by retailer and are subject to change.