DELTA 2 Max
- you want to grow to 6,144Wh later
- you’ll put up 1,000W of solar
- you plug in six AC devices plus USB
DELTA 3 Ultra
- you need 3,600W for big loads
- your RV takes a TT-30 plug
- a PC needs the 10ms UPS
Prices and stock checked by our price engine on November 13, 2026 at 6:29 AM EST. Each product is rechecked several times a day; the time refreshes when you load the page.
The Ultra is the bigger box on day one. The DELTA 2 Max is the one that can still grow on day 500.
The EcoFlow DELTA 2 Max stores 2,048Wh and delivers 2,400W from six AC outlets, takes 1,000W of solar on two ports and grows to 6,144Wh with two extra batteries, at 50 lb. The EcoFlow DELTA 3 Ultra stores 3,072Wh and delivers 3,600W with a 7,200W surge, adds a TT-30 RV outlet and switches to battery in under 10ms instead of about 30ms, but takes 800W of solar, has no battery port and weighs 72.1 lb. Prices sit $270 apart today. If you need the big inverter or an RV plug now, the Ultra; if you’d rather start at 2kWh and add batteries or panels later, the DELTA 2 Max.
Below: the differences with numbers, a 20-second calculator for your own gear, eight modeled situations, the cost of growing each one, a third option, and what published tests found.
The Ultra stores 1,024Wh more, delivers 1,200W more, adds a TT-30 and switches in under 10ms. The DELTA 2 Max weighs 22.1 lb less, takes 200W more solar, has six AC outlets and four USB-A, and grows to 6,144Wh. Prices sit $270 apart today.
- you’ll add batteries later
- you’ll use 1,000W of solar
- you move it: 50 lb
- you run 3,600W at once
- your RV uses a TT-30
- you protect a PC: 10ms
The five differences that decide it
Both use LFP cells, charge at 1,800W from the wall, have a 126W car socket and work with the EcoFlow app over Wi-Fi and Bluetooth. These five gaps decide it.
Will it run your setup? Check in 20 seconds
Estimates use 85% usable capacity and 70% of rated solar output. Real results vary with temperature, inverter load, shade and appliance cycling. Fridge and freezer watts are daily averages and do not include compressor startup surges.
Runtime by appliance, one at a time
Simple energy estimates, not measured runtimes. About 1,741Wh usable on the DELTA 2 Max and 2,611Wh on the DELTA 3 Ultra. StorageReview measured 1,800Wh out of a DELTA 2 Max at a 350W load; we found no independent capacity test of the Ultra.
Appliance for appliance, the Ultra lasts 50% longer than the DELTA 2 Max.
Same appliance, same watts: the gap is always the size of the battery.Get our Black Friday alerts for EcoFlow
We track live prices on 40+ models from Jackery, EcoFlow, BLUETTI and Anker SOLIX. When a deal beats the lowest price we've recorded, you'll hear from us. During Black Friday week, one short recap a day at most.
Unsubscribe in one click. We may earn a commission when you buy through our links, at no extra cost to you. Privacy Policy
The price gap, in numbers
The EcoFlow DELTA 3 Ultra costs $270 more than the EcoFlow DELTA 2 Max and adds 1,024Wh: that is $0.26 per extra Wh, against $0.50 per Wh for the DELTA 2 Max.
Prices refresh daily from EcoFlow US.What the $270 buys: half again the battery (3,072Wh vs 2,048Wh), 3,600W instead of 2,400W, a TT-30 and a 10ms UPS.
The DELTA 3 Ultra has no extra battery port: 3,072Wh is what you keep. The DELTA 2 Max takes one or two DELTA 2 Max Smart Extra Batteries, 6,144Wh in all, so it passes the Ultra’s capacity with the first one. If you want the Ultra’s 3,600W with room to grow, the DELTA 3 Ultra Plus is the expandable version. EcoFlow US prices move often; the figures here are refreshed daily by our price engine.
The third option: the DELTA 3 Ultra Plus at $1,599
EcoFlow DELTA 3 Ultra Plus: $1,599 today
The Ultra’s inverter with the DELTA 2 Max’s room to grow: 3,072Wh and 3,600W with a 7,200W surge from four 20A outlets and a TT-30, a 30A Anderson port, 1,600W of solar, a 10ms UPS and expansion to about 11kWh with DELTA Pro 3 Extra Batteries, at 74.3 lb. Our DELTA 3 Ultra review covers the platform. See the DELTA 3 Ultra Plus at EcoFlow.
Eight modeled situations, worked out
Same formula as the calculator above: 85% of the rated capacity, no extra battery. The fridge averages 60W, about 525kWh a year.
24-hour outage, essentials only
The Ultra covers a full day with hours to spare; the DELTA 2 Max most of one. One extra battery on the DELTA 2 Max takes it past the Ultra.
Microwave and space heater at once
Only the Ultra runs both. On the DELTA 2 Max, one at a time: X-Boost to 3,400W helps the heater, not the microwave.
RV with a 30A inlet
The Ultra takes the cord directly. The DELTA 2 Max needs an adapter to a household outlet and stops at 2,400W.
A desktop PC through a grid drop
About 30ms is longer than many desktop power supplies ride through, so a PC may reboot on the DELTA 2 Max. Gadgetoid called it poor as a UPS for sensitive desktops. The Ultra’s under-10ms switchover is the safer one.
Refill from solar, each at its maximum
The DELTA 2 Max refills in about half the time: a smaller battery and more solar input. The Ultra needs a long, clear day to fill from 800W of panels.
A full-size fridge, nothing else
The Ultra keeps food cold about 14.5 hours longer on one charge.
A bigger battery next year
Only the DELTA 2 Max grows: each Smart Extra Battery adds 2,048Wh. The Ultra has no battery port.
Moving it
Both are two-hand lifts. The Ultra is 22.1 lb heavier and bigger: plan for help or a cart.
Nine more differences, the spec sheet and the box
Smaller gaps that rarely decide the purchase, then the full specifications and what ships in the box.
DELTA 2 Max and DELTA 3 Ultra weight, dimensions and full specifications
Weight: 50 lb for the DELTA 2 Max and 72.1 lb for the DELTA 3 Ultra. Dimensions: 19.6 × 9.5 × 12 in and 24.6 × 12.9 × 15.5 in. Everything else is in the sheet below.
EcoFlow DELTA 2 Max and EcoFlow DELTA 3 Ultra full specifications
Every published figure for both units, grouped. Green marks the better value.
What’s in the box
DELTA 2 Max
- DELTA 2 Max2,048Wh, 50 lb
- AC charging cable
- User manual and warranty card
- Solar cable sold separately
- No car charging cable listed
DELTA 3 Ultra
- DELTA 3 Ultra3,072Wh, 72.1 lb
- AC charging cable
- Manuals and warranty card
- No solar or car cablesold separately
From the EcoFlow US product pages; bundles add the matching cables.
07 · ChargingHow fast each one refills
Shorter bar, faster refill. Each row is scaled to its slower unit.
DELTA 2 Max: StorageReview measured 2,370Wh drawn from the wall for a full refillDELTA 3 Ultra: no independent charging measurement found as of October 31, 2026
Our solar times assume panels deliver 70% of their rating; the brands’ figures assume ideal sun.
Every port, side by side
DELTA 2 Max
DELTA 3 Ultra
Practical consequence: the DELTA 2 Max has one more household outlet, three more USB-A ports and two DC barrels. The Ultra trades them for a TT-30 RV outlet, a 140W USB-C and four 20A outlets, but has no battery port.
09 · NoiseNoise: DELTA 2 Max vs Ultra
EcoFlow rates the EcoFlow DELTA 3 Ultra at 25dB or less at 600W. It publishes no rating for the EcoFlow DELTA 2 Max; Space.com found its fans fairly loud while charging, Gadgetoid didn’t hear them over a laptop in office use.
No reviewer has published a dB figure for either model.Every figure we found, with its source
No decibel figure published.
What reviewers heard: Fans come on while charging or under heavier loads and are fairly loud (Space.com, UK unit); in office use, not audible above laptop fans (Gadgetoid, UK unit).
Measured by a tester Brand figure
- The fans run hardest while fast charging, so lower the charging speed in the app at night.
Cold and heat: DELTA 2 Max vs Ultra
EcoFlow US gives the EcoFlow DELTA 3 Ultra a charging range of 32°F to 113°F and a running range of 14°F to 113°F. Its US page for the EcoFlow DELTA 2 Max publishes no range.
Figures from the EcoFlow US DELTA 3 Ultra page; the DELTA 2 Max page gives none.- Charge either one indoors in winter: the Ultra doesn’t charge below 32°F, and EcoFlow gives no range for the DELTA 2 Max.
App, UPS and smart features
The EcoFlow DELTA 3 Ultra is the better UPS, at under 10ms, and links to a 1,600W Smart Generator. The EcoFlow DELTA 2 Max answers with a battery port for up to 6,144Wh.
Same EcoFlow app. The gap is switchover speed and expansion.Green zone: a switch under about 16ms, which most desktop PCs ride through without restarting.
Can you add a battery later? The EcoFlow DELTA 2 Max takes up to two DELTA 2 Max or DELTA Max Smart Extra Batteries, 6,144Wh in all. EcoFlow lists the EcoFlow DELTA 3 Ultra’s max scalability as 0.
Does it prepare for storms? The EcoFlow DELTA 3 Ultra has Storm Guard, which charges ahead of severe weather. EcoFlow lists no such feature for the EcoFlow DELTA 2 Max.
Does AC stay on through an outage and recovery? The EcoFlow DELTA 2 Max has an AC Always On mode that keeps outlets live through outages and recovery. EcoFlow lists no such mode for the EcoFlow DELTA 3 Ultra.
Does it work as a UPS? The EcoFlow DELTA 3 Ultra switches in under 10ms. EcoFlow’s US page gives no switchover time for the EcoFlow DELTA 2 Max; reviewers quote EcoFlow’s 30ms EPS figure, fine for appliances, borderline for desktop PCs.
How much can a generator put in? The EcoFlow DELTA 3 Ultra charges from an EcoFlow Smart Generator at up to 1,600W; the EcoFlow DELTA 2 Max takes a generator through its 1,800W AC input.
How does the app connect? Both use the EcoFlow app over Wi-Fi and Bluetooth.
Warranty and support
The EcoFlow DELTA 2 Max gets 5 years from EcoFlow US with nothing to register. The EcoFlow DELTA 3 Ultra gets 3 years, plus 2 more once registered in the EcoFlow app.
Same 5 years at best; only the Ultra needs registration.Subject to each brand’s warranty terms and eligibility.
EcoFlow rates the DELTA 2 Max at 3,000 cycles to 80%, about 8 years at one full cycle a day. For the DELTA 3 Ultra it publishes no cycle count, only 10 years of reliable power. Calendar aging and heat also reduce capacity.
- Register the DELTA 3 Ultra in the EcoFlow app the day it arrives: without it, the warranty stops at 3 years.
- The DELTA 2 Max needs no registration for its 5 years; keep the proof of purchase.
What reviewers report
We have not lab-tested these two units. Here is what 5 published reviews found, with the source, author and date for each point. Reviews of UK and EU units are flagged: those models charge from 230V outlets and have different sockets, so their charge times and outlet findings don’t carry over to US units.
DELTA 2 Max: StorageReview (July 2023), Trusted Reviews (January 2024, UK unit), Digital Trends (June 2023), Space.com (September 2023, UK unit), Gadgetoid (October 2023, UK unit)DELTA 3 Ultra: no verifiable independent test found
Usable capacity
- DELTA 2 MaxReviewer With a 350W load, the AC inverter delivered 1,800Wh from the 2,048Wh battery. StorageReview, Kevin OBrien, July 2023
- DELTA 2 MaxReviewer Discharging into a ~1,000W fan heater delivered 1.709kWh, 83.45 percent efficient. Trusted Reviews, David Ludlow, January 2024, UK unit
Charging
- DELTA 2 MaxReviewer A full recharge at the highest rate needed 2,370Wh from the wall. StorageReview, Kevin OBrien, July 2023
- DELTA 2 MaxReviewer A full AC top-up drew 2,203Wh from the wall. Flag: UK 230V charging. Trusted Reviews, David Ludlow, January 2024, UK unit
- DELTA 2 MaxReviewer Wall charging drew a steady 1,590W, 210W below the 1,800W claim but still best in its class then. Digital Trends, Nick Mokey, June 2023
- DELTA 2 MaxReviewer From 30 percent it reached 80 percent in almost exactly 40 minutes on a UK 13A plug. Flag: 230V. Space.com, Tantse Walter, September 2023, UK unit
Noise and heat
- DELTA 2 MaxReviewer Fans come on while charging or under heavier multi-device loads and are fairly loud. Space.com, Tantse Walter, September 2023, UK unit
- DELTA 2 MaxReviewer In daily office use, fan noise was not audible above the laptop fans and heat was minimal. Gadgetoid, Phil (Gadgetoid), October 2023, UK unit
UPS and output
- DELTA 2 MaxReviewer As an EPS, the battery takes over within 30ms, too slow for some servers and medical devices. Trusted Reviews, David Ludlow, January 2024, UK unit
- DELTA 2 MaxReviewer A table saw plus 5HP shop vac ran together at a sustained 2,253W without issue. Digital Trends, Nick Mokey, June 2023
- DELTA 2 MaxReviewer The miter saw tripped it initially; a heater plus heat gun near 2,400W was sustained for the long haul. Digital Trends, Nick Mokey, June 2023
- DELTA 2 MaxReviewer Notes the roughly 30ms switchover makes it poor as a UPS for sensitive desktops. Gadgetoid, Phil (Gadgetoid), October 2023, UK unit
Practical limits before you buy
- The DELTA 3 Ultra can’t be expanded. EcoFlow lists its max scalability as 0; the Ultra Plus is the expandable version.
- The DELTA 2 Max’s EPS is about 30ms, per EcoFlow’s figure as reviewers quote it: fine for appliances, borderline for desktop PCs.
- The DELTA 2 Max reaches 1,000W of solar only with both ports used: 500W per port.
- The Ultra weighs 72.1 lb and measures 24.6 in long. Plan where it lives.
- Register the Ultra in the EcoFlow app for the full 5 years; without it, 3.
- X-Boost is for heating loads only. Motors need the continuous rating: 2,400W or 3,600W.
- Neither delivers 240V.
- No independent test of the DELTA 3 Ultra we could verify yet: its figures here are EcoFlow’s.
Frequently asked questions
What is the difference between the EcoFlow DELTA 2 Max and the DELTA 3 Ultra?
The Ultra stores 3,072Wh against 2,048Wh, delivers 3,600W against 2,400W, adds a TT-30 and switches in under 10ms instead of about 30ms. The DELTA 2 Max weighs 50 lb against 72.1 lb, takes 1,000W of solar against 800W and expands to 6,144Wh; the Ultra can’t be expanded.
Can the DELTA 3 Ultra be expanded?
No. EcoFlow lists its max scalability as 0. The DELTA 3 Ultra Plus is the expandable 3kWh model.
Which is better as a UPS?
The Ultra: under 10ms. EcoFlow’s US page gives no time for the DELTA 2 Max; reviewers quote EcoFlow’s 30ms EPS figure.
Which is better for an RV?
The Ultra, thanks to its TT-30 outlet and 3,600W. The DELTA 2 Max needs an adapter for a 30A cord.
Which refills faster from solar?
The DELTA 2 Max: about 2.9 hours from 1,000W of panels against about 5.5 hours from 800W on the Ultra, at 70% of panel rating.
How long will each run a refrigerator?
At a 60W average: about 29 hours on the DELTA 2 Max and 43.5 hours on the Ultra.
How many outlets does each have?
The DELTA 2 Max has six AC outlets, two 100W USB-C, four USB-A, a 12V car socket and two DC barrels. The Ultra has four 20A outlets, a TT-30, three USB-C, one USB-A and a 12V car socket.
What warranty do they have?
5 years for the DELTA 2 Max with no registration condition; 3 years for the Ultra, 5 with app registration, per EcoFlow’s US warranty table.
Is there a third option?
The DELTA 3 Ultra Plus: the Ultra’s 3,072Wh and 3,600W, plus a 30A Anderson port, 1,600W of solar and expansion to about 11kWh, at 74.3 lb.
Related comparisons and reviews
How we compared and sources
Research-based comparison. We have not physically tested these two units. Specs come from the EcoFlow US product pages and the EcoFlow US warranty table; usage observations are attributed to named reviewers. Prices and availability were checked on October 31, 2026.
- Specs: EcoFlow US, DELTA 2 Max; and EcoFlow US, DELTA 3 Ultra; read on October 31, 2026. Warranty terms from the EcoFlow US warranty policy. DELTA 3 Ultra: no independent test found as of October 31, 2026.
- Reviewer reports on the DELTA 2 Max: StorageReview, Kevin OBrien, July 2023, Trusted Reviews, David Ludlow, January 2024, UK unit, Digital Trends, Nick Mokey, June 2023, Space.com, Tantse Walter, September 2023, UK unit, Gadgetoid, Phil (Gadgetoid), October 2023, UK unit.
- Runtime = capacity × 0.85 ÷ watts. Solar harvest = min(panel watts, max input) × sun hours × 0.70. Cost per lifetime kWh = price ÷ (cycles × capacity in kWh).
The Ultra adds 1,024Wh, 1,200W, a TT-30 and a 10ms UPS; the DELTA 2 Max is 22 lb lighter and grows to 6,144Wh. Prices sit $270 apart.
Prices checked November 13, 2026 at 6:29 AM EST
Looking at other models? Browse all power station comparisons, or pick any two models on the hub and we point you to the right duel.
Originally published: November 7, 2026