EcoFlow DELTA Pro Review: specs and runtime

Specifications checked against manufacturer pages on 2026-08-24.

The EcoFlow DELTA Pro pairs 3,600 Wh of LFP cells with a 3,600 W inverter, which puts it in the large bracket. We read every figure below off EcoFlow’s own product page on 2026-08-24, calculated what the rated capacity does to a set of household appliances, and listed what the page leaves out. Where a number is ours rather than the maker’s, the row says which.

In short. 3,600 Wh in the large band: $0.78/Wh at the list price we recorded; 36.4 Wh per pound; 3,500 rated cycles to 80%. On our assumptions a full-size refrigerator calculates to 2.0–2.3 days, and a 40 W CPAP calculates to 2.6–3.1 days. 2 rows we track are blank on the maker’s page; the section below says which. Every hour figure above is arithmetic, not a measurement.

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Check the current price

EcoFlow DELTA Pro on Amazon

It resolves to the same base model the table above describes, without accessories. Amazon prices change daily.

Who it is for, and who should skip it

Read this first; it decides whether the rest of the page is for you.

It fits if

A refrigerator is what you are saving. It clears a 12-hour outage on our assumptions with about 36 hours to spare, and the stated 7,200 W surge covers a roughly 900 W start.
One night of CPAP, with a caveat. A 40 W machine without a humidifier runs the night with margin, though the maker states no switchover time, so we cannot say the machine rides through the transfer. A heated humidifier changes that arithmetic.
Your outages run past a day. Up to 1,600 W of solar input is what decides whether day two starts full or empty.

Skip it if

It has to travel. At 99 lb this needs two people or a cart; it lives where you put it.
You need a seamless handover. EcoFlow states no UPS transfer time, so a desktop or a CPAP may notice the gap.
You own a large array already. It takes at most 1,600 W of solar; panels past that ceiling idle rather than charge it faster.

Every published specification

Where a row carries a number, a note under the table says where it came from. A row reading “Manufacturer does not state” is the maker’s silence; “Not yet verified by CalmWatt” is ours.

Specification	EcoFlow DELTA Pro
Rated capacity	3,600 Wh¹
Usable capacity (calculated)^*	3060–3240 Wh
Continuous AC output	3,600 W²
Surge output	7,200 W³
Full recharge from wall	162 min⁴
Cell chemistry	LFP⁵
Rated cycle life	3,500 cycles to 80%^6,7
UPS switchover	Manufacturer does not state
Expandable	Yes — 25,000 Wh only as a multi-unit system; 10,800 Wh on a single unit^8,9
Max solar input	1,600 W¹⁰
Max AC charging input	3,000 W¹¹
AC outlets	5¹²
Highest USB-C port	100 W¹³
App control	Manufacturer does not state
Stated noise	48–60 dB¹⁴
Warranty	3 years¹⁵
Weight	about 99 lb¹⁶
Manufacturer list price when checked	$2,799¹⁷

^* Calculated: rated capacity × an assumed 85–90% conversion efficiency. No maker publishes a usable figure.

Notes on the figures

DELTA Pro, rated capacity: Rated capacity of the base unit before any extra batteries are added.
DELTA Pro, continuous output: Rated continuous AC output across all outlets combined; an X-Boost mode supports resistive devices up to 4,500 W.
DELTA Pro, surge: Conventional surge rating; the page separately markets a boost mode of 4500 W for resistive loads.
DELTA Pro, full recharge: Full recharge from a standard wall outlet at 1,800 W takes 2.7 hours (162 minutes), the figure we use; the maker also states 1.7 hours at an EV charging station (3,400 W) and 1.9 hours with dual AC plus solar charging.
DELTA Pro, cell chemistry: LFP is lithium iron phosphate chemistry.
DELTA Pro, cycle life: To 80% of original capacity; the same specification line also states 6,500 cycles to 50% capacity.
DELTA Pro, cycle life: Remaining-capacity endpoint paired with the 3,500-cycle figure; the maker also states 6,500 cycles to a 50% endpoint.
DELTA Pro, expandable: Each unit supports up to two DELTA Pro Smart Extra Batteries or Smart Generators.
DELTA Pro, expandable: Upper bound for a whole-system setup that requires two DELTA Pro units with extra battery packs plus two Smart Generators; a single DELTA Pro with two extra batteries reaches 10.8 kWh.
DELTA Pro, solar input: Maximum solar charging input; the solar input voltage range is 11-150 V at up to 15 A.
DELTA Pro, AC input: Maximum AC input at 240 V; on a standard 120 V outlet the maximum is 1,800 W.
DELTA Pro, AC outlets: The specifications table lists five AC outlets; the page’s FAQ separately counts four 20 A household AC outlets among the unit’s output ports.
DELTA Pro, USB-C: Per port; the unit has two USB-C ports.
DELTA Pro, noise: Measured at a 1-meter distance; the level varies with the wattage flowing in or out of the battery and with temperature.
DELTA Pro, warranty: EcoFlow states a 3-year standard warranty; a 2-year extension requires EcoFlow App registration, so per our policy we count the base three years.
DELTA Pro, weight: Approximate net weight stated by the manufacturer.
DELTA Pro, price: List price; a sale price of $1,899 was shown, and a members-only final price of $1,799 was also advertised.

What EcoFlow does not state

The omissions are the part other pages copy from each other without noticing. Every gap on this unit’s page, named rather than quietly filled in. 29 of the 34 units in our database omit something, and this one is among them with 2 figures.

Ups switchover time. Absent from EcoFlow’s specifications for this unit when we checked.
Whether the unit has app control. Absent from EcoFlow’s specifications for this unit when we checked.
Usable capacity. Universally absent. The band in the table above is our calculation from an assumed efficiency, not a figure anyone publishes.

This is not a mark against the product. It is a warning about pages that fill these rows in without saying where the number came from.

What it runs, and for how long

Every unit we cover meets the same appliance list, so nothing below is tuned to flatter this one.

Appliance	DELTA Pro
Full-size refrigerator 150 W, 900 W start, 35% duty · eff. 70%–82%	2.0–2.3 days
Mini fridge 70 W, 400 W start, 30% duty · eff. 70%–82%	5.0–5.9 days
CPAP without humidifier 40 W · eff. 70%–82%	2.6–3.1 days
CPAP with heated humidifier 95 W · eff. 70%–82%	27–31 hr
Gas furnace blower 400 W, 1600 W start, 40% duty · eff. 80%–87%	18–20 hr
1/3 hp sump pump 500 W, 1800 W start, 15% duty · eff. 80%–87%	38–42 hr
Router and modem 20 W · eff. 70%–82%	5.2–6.1 days
Laptop 60 W · eff. 70%–82%	1.8–2.1 days
1500W space heater 1500 W · eff. 85%–90%	2.0–2.2 hr

These are calculations, not measurements: hours = rated Wh × efficiency ÷ (appliance W × duty). The assumptions behind every figure are listed on How we verify; “Unlikely to start” means the appliance surge is above the stated rating.

The same specs, normalized

Measure	DELTA Pro
Cost per watt-hour	$0.78/Wh
Watt-hours per pound	36.4 Wh/lb
Surge headroom	2.00×
Recharge rate	22.2 Wh/min
Rated cycle life	3,500 cycles to 80%
Continuous watts per dollar	1.29 W/$

These are measurements of shape, not scores. What each one means and which direction is better is on How we verify.

What those figures actually mean

Cost per watt-hour: $0.78/Wh. The $2,799 list price we recorded over 3,600 Wh of rated capacity. It is the one figure that compares a small unit with a large one honestly, and the figure a sale moves fastest. Recompute it against the price you are shown.

Watt-hours per pound: 36.4 Wh/lb. 3,600 Wh in 99 lb makes this a cart-or-two-people unit. Weight per watt-hour is the cost of the chemistry, not of the design.

Surge headroom: 2.00×. A stated 7,200 W surge over a 3,600 W continuous rating, which covers the roughly 900 W a full-size refrigerator needs to start. Headroom decides whether the appliance starts at all; the hours only matter afterwards.

Recharge rate: 22.2 Wh/min. A full wall charge in 162 minutes. On day three this matters more than capacity does.

Rated cycle life: 3,500 cycles to 80% capacity. That is about 67 years at a cycle a week. Outage use never gets near it; van and off-grid use can. The percentage matters as much as the count: two ratings only compare when they name the same remaining capacity.

Continuous watts per dollar: 1.29 W/$. If your plan is one heavy appliance rather than several light ones for days, this is the ratio that describes your purchase.

Where it sits in our database

A single unit’s figures do not say whether a number is large or small. Ours do, because every unit below was transcribed the same way.

Measure	DELTA Pro	Among verified units
Rated capacity	3,600 Wh	3rd largest of 34
Continuous AC output	3,600 W	4th highest of 34
Cost per watt-hour	$0.78/Wh	21st cheapest of 32
Watt-hours per pound	36.4 Wh/lb	19th densest of 34
Weight	99 lb	32nd lightest of 34

Rank is not a recommendation: the smallest unit here is the right answer for somebody. The row built on price uses the manufacturer list price recorded on 2026-08-24; the retail price behind our link moves independently, so recompute that row against what you are shown.

Three outages, and the figure that decides each

One night, one CPAP. A 40 W CPAP without a humidifier calculates to 2.6–3.1 days. With no stated switchover time, published figures cannot say whether it rides through the transfer or restarts.
Twelve hours, one refrigerator. A typical full-size refrigerator calculates to 2.0–2.3 days, and the stated 7,200 W surge covers its roughly 900 W start.
The loads people forget. A gas furnace blower calculates to 18–20 hr and a one-third horsepower sump pump calculates to 38–42 hr. In most houses neither has a plug, so the answer runs through a transfer switch, not an inverter. A router and modem, meanwhile, calculates to 5.2–6.1 days.
Three days, with something to recharge from. A full wall recharge takes 162 minutes, and it accepts up to 1,600 W of solar, so day two turns on your panels and your sky.

The DELTA Pro against other units

Ratios need something to sit beside. The DELTA Pro appears in 4 head-to-head pages here, each built from the same manufacturer figures.

Questions people ask about the DELTA Pro

No answer here uses a number that is not on this page.

How long will the DELTA Pro run a refrigerator?

2.0–2.3 days on our assumptions for a typical full-size unit at 150 W running and a 35% duty cycle. The stated surge covers the roughly 900 W start. A newer or smaller refrigerator will beat this figure.

Can the DELTA Pro run a CPAP all night?

Yes on capacity: a 40 W machine without a humidifier calculates to 2.6–3.1 days against the eight hours a night usually needs. No switchover time is stated, so we cannot say whether it restarts. Heated tubing and a humidifier change this figure sharply.

How long does the DELTA Pro take to recharge?

162 minutes from a wall outlet on the maker’s figure, with up to 1,600 W accepted from solar. Refill speed is what a multi-day outage actually tests.

How much does the DELTA Pro weigh?

99 lb on the maker’s figure, or 36.4 Wh of rated capacity carried per pound. That is a cart-or-two-people unit, which is why units this size tend to stay where you put them.

How many cycles is the DELTA Pro rated for?

3,500 cycles to 80% of original capacity, on LFP cells, which is roughly 67 years at one cycle a week. Check the percentage before comparing this with another maker’s number.

Can you expand the DELTA Pro’s capacity?

Yes, but read the headline number carefully. The 25,000 Wh the maker quotes is a whole-system figure that needs more than one unit; a single DELTA Pro with extra batteries reaches 10,800 Wh. Budget against the single-unit figure unless you intend to buy the whole system.