Head-to-head test
EcoFlow DELTA Pro Ultra X vs Anker SOLIX C300 DC
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 Pro Ultra X
14,944Power Score · Whole-Home Capable
$7,999.00 list · direct from EcoFlow
Anker
SOLIX C300 DC
1,621Power Score · Device Hub
$199.99 list · direct from Anker
Spec deltas
The EcoFlow DELTA Pro Ultra X (12,288Wh) and Anker SOLIX C300 DC (288Wh) 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 DELTA Pro Ultra X has a slight edge, but the margin is close enough that your use case should break the tie.
What the spec gap means in practice: the DELTA Pro Ultra X's 12,000W inverter has the headroom for a window AC, a full-size fridge, and power tools. The SOLIX C300 DC's 300W inverter can't start the heaviest of those — a window AC or a high-surge power tool will trip it. On stamina, the DELTA Pro Ultra X keeps a fridge alive for roughly 70 hours vs the SOLIX C300 DC's 2 hours. The cost? Portability. At 298.7 lbs, the DELTA Pro Ultra X is a two-person lift you set down once and leave. The SOLIX C300 DC at 6.2 lbs is something one person can actually carry.
Pick the DELTA Pro Ultra X if your primary use is weekend camping or 8-hour blackout. Go with the SOLIX C300 DC if its specific strengths below line up better with your use. Most buyers stop at the sticker price and miss this: over a full lifespan the DELTA Pro Ultra X works out to about $0.19/kWh against the SOLIX C300 DC's $0.23, a gap that compounds in the DELTA Pro Ultra X'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 Pro Ultra X
With a massive 12,000W output (and 45,000W surge), the DELTA Pro Ultra X can run high-wattage appliances like space heaters, hair dryers, and electric grills without tripping. Weighing in at 298.7 lbs, this is not a unit you want to carry far. It's best suited as a stationary backup or RV companion.
Strengths
- +Larger battery capacity
- +Higher AC output
- +Longer warranty
- +Faster solar charging
Trade-offs
- –Substantially more expensive (+$7,799) than the SOLIX C300 DC.
- –Significantly heavier (+292.5 lbs), making it harder to move.
- –Very heavy unit that may be difficult for one person to lift.
Anker SOLIX C300 DC
At 300W, this unit is strictly for personal electronics (phones, laptops) and small CPAP machines. Do not expect to run kitchen appliances. At only 6.2 lbs, it is exceptionally portable. You can easily carry it one-handed to a campsite or tailgating party.
Strengths
- +Costs $7,799 less
- +Lighter by 292.5 lb
Trade-offs
- –Weaker inverter (-11,700W) limits appliance compatibility.
- –Sealed capacity — the DELTA Pro Ultra X can add batteries to grow past 288Wh; 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
DELTA Pro Ultra X
The SOLIX C300 DC runs out of juice. It only has 245Wh usable, but this scenario needs 2,100Wh. The DELTA Pro Ultra X covers it and still has 556h of phone charging left over.
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 X
The SOLIX C300 DC runs out of juice. It only has 245Wh usable, but this scenario needs 1,645Wh. The DELTA Pro Ultra X covers it and still has 587h of phone charging left over.
Battery budget usedlower = more headroom
LOAD Fridge 150W×8h · Router + Modem 20W×8h · LED Lights (4 bulbs) 40W×6h · Phone Charger 15W×3h
SCN-03 · 8 hours · needs 320Wh
CPAP Overnight
Sleep therapy without interruption — the #1 medical use case
DELTA Pro Ultra X
The SOLIX C300 DC runs out of juice. It only has 245Wh usable, but this scenario needs 320Wh. The DELTA Pro Ultra X covers it and still has 675h of phone charging left over.
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 X
The SOLIX C300 DC runs out of juice. It only has 245Wh usable, but this scenario needs 910Wh. The DELTA Pro Ultra X covers it and still has 636h of phone charging left over.
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 Ultra X
The SOLIX C300 DC's 300W output can't handle the 400W peak demand. The DELTA Pro Ultra X handles this scenario with 9,775Wh to spare.
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 X
The SOLIX C300 DC runs out of juice. It only has 245Wh usable, but this scenario needs 4,685Wh. The DELTA Pro Ultra X covers it and still has 384h 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: DELTA Pro Ultra X runs 51h vs 1.2h.
$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 0–696.3hComfort & Convenience
Makes off-grid life actually enjoyablescale 0–139.3hHigh-Draw Appliances
These reveal the real limitsscale 0–10.4h¹ 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 DELTA Pro Ultra X, on Power Score margin
These two units are closely matched on individual specs, but our Power Score analysis gives the DELTA Pro Ultra X the edge with a composite score of 14,944 vs 1,621.
Overall score margin: 14,944 vs 1,621 (+821.9%)
List prices as of July 10, 2026. The links below open EcoFlow's and Anker's current prices.
$7,999.00 list · direct from EcoFlow
or check the SOLIX C300 DC price$199.99 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): Home Backup, 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.
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 X rates 4.6/5 (75th percentile of 17 Whole-Home / Off-Grid-class units), and SOLIX C300 DC rates 4.2/5 (52nd percentile of 22 Personal-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.
DELTA Pro Ultra X: 298.7 lbs Is a Commitment
At 298.7 lbs, this is a two-person lift. Plan your placement carefully. Once it's set up, you won't want to move it. It's a semi-permanent appliance. Pick your spot.
SOLIX C300 DC: Fixed Capacity
The SOLIX C300 DC is sealed at 288Wh — fine if that covers you, but it's the ceiling. The DELTA Pro Ultra X starts at 12,288Wh and can add expansion batteries, so if your needs may climb toward partial-home backup, it has room to grow the SOLIX C300 DC doesn't.
Only the DELTA Pro Ultra X Has UPS Protection
The DELTA Pro Ultra X can act as an uninterruptible power supply. Plug your PC, router, or CPAP into it and it switches to battery seamlessly during an outage. The SOLIX C300 DC doesn't have this feature, so connected devices will experience a power interruption.
Warranty Value Comparison
The SOLIX C300 DC gives you 15 years of warranty per $1,000 spent, vs the DELTA Pro Ultra X's 0.6 years. That's 24× more coverage per dollar. An underrated factor if you're keeping this unit for years.
SOLIX C300 DC: Noise Level Not Disclosed
The DELTA Pro Ultra X publishes its noise level (30dB), but the SOLIX C300 DC doesn't. Brands that don't disclose noise specs often have louder units. If noise matters to you (CPAP users, apartment dwellers), this is worth investigating before buying.
Full record above — the Test Desk pick is the DELTA Pro Ultra X.
Check DELTA Pro Ultra X price →or check the SOLIX C300 DC 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 SOLIX C300 DC is cheaper to buy, but the DELTA Pro Ultra X is cheaper to own. At $0.19/kWh over its lifetime vs $0.23/kWh, the DELTA Pro Ultra X'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. 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.
Anker
Ecosystem
7-8 SOLIX portable power stations across C-series (compact) and F-series (flagship), plus the X1 home energy system
Support
US-based support. Historically known for incredible no-hassle replacements, but recent reports describe AI-driven support agents giving generic responses and complex return logistics for heavy units (hazmat shipping). The Anker brand reputation is still strong, but SOLIX-specific support quality is trending down.
Community
Moderate — active Reddit (r/Anker, r/AnkerSOLIXCommunity) and growing. Benefits from Anker's massive consumer electronics brand awareness.
App experience
Rated 4.5/5 iOS (~1,100 ratings) · 4.3/5 Android
Unique strength
Parent brand trust from Anker's consumer electronics dominance. InfiniPower technology for long cycle life. Gen 2 lineup offers exceptional $/Wh value — some of the best in the market.
Worth knowing
Support quality appears to be declining from its historically excellent level. Firmware updates have removed features without warning. Expansion ecosystem is smaller than EcoFlow's.
Analyst note
EcoFlow positions itself as a mid-to-premium brand with stronger support infrastructure, while Anker competes on value. The question is whether the EcoFlow ecosystem and support premium is worth it for your use case.
Growth path
DELTA Pro Ultra X
EXPANDABLESupports EcoFlow expansion batteries, so you can add capacity later without replacing the base unit — useful if your needs may climb past 12,288Wh.
Accepts up to 10,000W 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.
SOLIX C300 DC
FIXED CAPACITYFixed at 288Wh, with no expansion — so size it for your needs up front rather than planning to add capacity later.
Accepts up to 100W 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 SOLIX C300 DC is sealed at 288Wh, which is fine if that covers you. The DELTA Pro Ultra X starts at 12,288Wh and can grow beyond it with EcoFlow expansion batteries — real headroom the SOLIX C300 DC doesn't have if your needs climb toward partial-home backup.
The Bottom Line
The full picture comes down to this. The DELTA Pro Ultra X 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 SOLIX C300 DC wins in the scenarios that match your life, it's the right choice regardless of aggregate scores.
If neither the DELTA Pro Ultra X nor the SOLIX C300 DC feels like the right fit, your power needs probably sit outside what these two target. Use our comparison tool above to explore alternatives that better match your specific wattage and runtime requirements. Prices on portable power stations fluctuate frequently. Both EcoFlow and Anker 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 DELTA Pro Ultra X worth $7,799 more than the SOLIX C300 DC?
The short answer: yes, if you'll actually use the extra capability. The DELTA Pro Ultra X costs $7,799 more, but that premium buys you 12,000Wh more battery capacity (that's 68 extra hours of running a mini-fridge); 11,700W higher AC output (opening the door to more demanding appliances); a longer-lasting battery rated for 3,500 cycles — that's 10 years at daily use; 9,900W faster solar charging for quicker off-grid recovery. On a cost-per-watt-hour basis, you're paying $0.65/Wh vs $0.69/Wh. Factor in cycle life and the math flips: the DELTA Pro Ultra X costs $0.19/kWh over its lifetime vs $0.23/kWh. The "expensive" unit is actually cheaper to own. For regular use, we'd pay the premium.
How does the 12,000Wh capacity difference actually affect daily use?
The DELTA Pro Ultra X's 12,288Wh battery keeps a mini-fridge running for roughly 70 hours vs the SOLIX C300 DC's 2 hours. Where it really matters: during an 8-hour blackout running your fridge, router, lights, AND charging your phone simultaneously (about 1,645Wh total), the DELTA Pro Ultra X handles it while the SOLIX C300 DC runs dry. What specs don't mention: runtime drops 20-30% in cold weather (below 32°F/0°C) as battery chemistry slows down. The DELTA Pro Ultra X'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 DELTA Pro Ultra X, or is the SOLIX C300 DC the only portable option?
The SOLIX C300 DC at 6.2 lbs is genuinely grab-and-go. Toss it in a backpack, carry it one-handed to a picnic, take it on a boat. The DELTA Pro Ultra X at 298.7 lbs is a different story. It's like carrying a large suitcase full of books. If you're setting up and breaking down camp frequently, this weight difference will exhaust you by day two.
How fast can each unit recharge from solar panels in real conditions?
On paper, the DELTA Pro Ultra X accepts 10,000W vs the SOLIX C300 DC's 100W 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 1.8 hours for the DELTA Pro Ultra X and 4.1 hours for the SOLIX C300 DC. That gap widens on cloudy days, when the DELTA Pro Ultra X'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 DELTA Pro Ultra X's advantage is substantial.
Can I use the DELTA Pro Ultra X as a home UPS to protect my electronics during blackouts?
Yes. The DELTA Pro Ultra X has UPS mode with true 0ms switchover (double-conversion). Even hospital-grade equipment won't notice. Plug in your desktop PC, router, NAS, or CPAP machine and it switches to battery seamlessly when the grid drops. The SOLIX C300 DC does not have this feature. Without UPS, a blackout means: your PC reboots (potentially corrupting unsaved work), your NAS may corrupt its drive array, your CPAP alarms and wakes you up, and your security cameras go dark until you manually switch them over. If always-on power protection matters, this is a dealbreaker advantage for the DELTA Pro Ultra X.
What if I need more capacity than the SOLIX C300 DC's 288Wh later?
The SOLIX C300 DC is sealed at 288Wh, so if you expect your needs to climb, the DELTA Pro Ultra X is the more future-proof pick: it starts at 12,288Wh and adds EcoFlow-compatible batteries without replacing the base unit. That said, "not expandable" isn't a flaw on its own — if 288Wh comfortably covers your loads, the SOLIX C300 DC is a complete unit, not a downgrade.
Is EcoFlow or Anker 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. Anker: 5-year warranty standard on portable stations, 10-year on home energy systems. Historically very reliable, though some recent firmware updates have altered product functionality without notice or rollback option. 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 Pro Ultra X or the SOLIX C300 DC?
We'd pay the premium for the DELTA Pro Ultra X. 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 SOLIX C300 DC is still solid if budget is the priority, but the DELTA Pro Ultra X 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 Pro Ultra XPick
$7,999.00
$7,999.00 list · direct from EcoFlow
Anker SOLIX C300 DC
$199.99
$199.99 list · direct from Anker
Prices may vary by retailer and are subject to change.