Specifications checked against manufacturer pages on 2026-08-23.
The EcoFlow DELTA 2 (1,024 Wh, 1,800 W) and the EcoFlow DELTA 3 (1,024 Wh, 1,800 W), compared on the figures their makers publish. EcoFlow changed 7 published figures between them — surge output, full recharge from wall, rated cycle life, among others — and states 1 more only for one of the two.
In short. The DELTA 3 leads on every normalized measure that could be decided: surge headroom (2.00× vs 1.50×), recharge rate (18.3 Wh/min vs 12.8 Wh/min) and rated cycle life (4,000 vs 3,000). The other 3 of 6 tie or cannot be compared. Read the runtime table before deciding — a clean sweep on ratios does not mean the other unit fails your outage. Note that the DELTA 2 has left the manufacturer’s catalog; see the catalog note below.
Check the current price
Links go to the exact base unit we compared, not a bundle. Amazon prices change daily.
We do not link the DELTA 2: we could not confirm a listing for the exact base unit, and we do not link a guess.
Catalog status, checked 2026-08-23. The EcoFlow DELTA 2’s store listing on the manufacturer’s site now redirects to a newer model, and the unit no longer appears in the manufacturer’s product-series catalog. It has been superseded by the EcoFlow DELTA 3. Its marketing page, with the spec tab we read the figures from, was still online when checked. Retailers may still sell remaining stock. That changes the question from “which is better” to “is a lower price worth buying a model the maker has moved on from” — see Buying a superseded model below.
Specifications, side by side
Numbered notes below the table give the source location or a caveat for figures that need one; check marks
mark the better figure where one can be judged; “Manufacturer does not state” means absent from that maker’s page as of
its check date listed under Sources. UPS switchover is how long the outlets go dark when grid power drops.
| Specification | EcoFlow DELTA 2 | EcoFlow DELTA 3 |
|---|---|---|
| Rated capacity | 1,024 Wh | 1,024 Wh |
| Usable capacity (calculated)* | 870–922 Wh | 870–922 Wh |
| Continuous AC output | 1,800 W | 1,800 W |
| Surge output | 2,700 W1 | 3,600 W ✓ |
| Full recharge from wall | 80 min2 | 56 min3 ✓ |
| Cell chemistry | LiFePO4 | LiFePO4 |
| Rated cycle life | 3,000+ cycles to 80%4 | 4,000 cycles to 80%+ ✓ |
| UPS switchover | 30 ms | <10 ms5 |
| Expandable | Yes, up to 3,000 Wh6 | Yes, up to 5,000 Wh |
| Max solar input | 500 W | 500 W |
| Max AC charging input | 1,200 W | 1,500 W ✓ |
| AC outlets | 67 | 6 |
| Highest USB-C port | 100 W8 | 100 W |
| App control | Yes9 | Yes |
| Stated noise | <60 dB10 | <30 dB11 |
| Warranty | 5 years12 | 5 years |
| Weight | about 27 lb13 | about 27.6 lb14 |
| Manufacturer list price when checked | Manufacturer does not state | $69915 |
* Calculated: rated capacity × an assumed 85–90% conversion efficiency; no maker publishes a usable figure.
Notes on the figures
- DELTA 2, surge: From the Output section of EcoFlow’s spec tab.
- DELTA 2, full recharge: Stated as 0–100%.
- DELTA 3, full recharge: With the 1,500 W AC input setting.
- DELTA 2, cycle life: EcoFlow’s DELTA 2 page gives two different figures: ‘3000+’ cycles in the description and ‘4000 cycles to 80%+’ in the spec tab. We use the lower one.
- DELTA 3, UPS switchover: Stated as under 10 ms; an upper bound.
- DELTA 2, expandable: 3 kWh with two extra batteries; 2,048 Wh with one.
- DELTA 2, AC outlets: Product page Specs tab, ‘Output’ section.
- DELTA 2, USB-C: Not stated as text on the product page (Specs tab only says ‘Number of USB-C Output 2’; the Specs-tab product image shows the printed port label ‘USB-C 100W’).
- DELTA 2, app: Product page FAQ (‘What connection methods do the APP support?’).
- DELTA 2, noise: Product page Specs tab.
- DELTA 3, noise: Stated as under 30 dB at 600 W output and under 40 dB at 1,200 W; an upper bound at a stated load.
- DELTA 2, warranty: Product page Specs tab.
- DELTA 2, weight: Manufacturer states ‘approx.’
- DELTA 3, weight: Manufacturer states ‘approx.’
- DELTA 3, price: Manufacturer list price when checked; on sale at $569 that day.
The same specs, normalized
Ratios, so the bigger unit does not win by default.
| Measure | DELTA 2 | DELTA 3 |
|---|---|---|
| Cost per watt-hour | Not comparable — EcoFlow does not state a price for the DELTA 2. | |
| Watt-hours per pound | 37.9 Wh/lb (within 3%) | 37.1 Wh/lb (within 3%) |
| Surge headroom | 1.50× | 2.00× ✓ |
| Recharge rate | 12.8 Wh/min | 18.3 Wh/min ✓ |
| Rated cycle life | 3,000 | 4,000 ✓ |
| Continuous watts per dollar | Not comparable — EcoFlow does not state a price for the DELTA 2. | |
Definitions and direction of each ratio: How we verify.
What each one runs, for how long
| Appliance | DELTA 2 | DELTA 3 |
|---|---|---|
| Full-size refrigerator 150 W, 900 W start, 35% duty · eff. 80%–87% |
16–17 hr | 16–17 hr |
| Mini fridge 70 W, 400 W start, 30% duty · eff. 70%–82% |
34–40 hr | 34–40 hr |
| CPAP without humidifier 40 W · eff. 70%–82% |
18–21 hr | 18–21 hr |
| CPAP with heated humidifier 95 W · eff. 80%–87% |
8.6–9.4 hr | 8.6–9.4 hr |
| Gas furnace blower 400 W, 1600 W start, 40% duty · eff. 85%–90% |
5.4–5.8 hr | 5.4–5.8 hr |
| 1/3 hp sump pump 500 W, 1800 W start, 15% duty · eff. 85%–90% |
about 12 hr | about 12 hr |
| Router and modem 20 W · eff. 70%–82% |
36–42 hr | 36–42 hr |
| Laptop 60 W · eff. 70%–82% |
12–14 hr | 12–14 hr |
| 1500W space heater 1500 W · eff. 82%–88% |
about 0.6 hr | about 0.6 hr |
Calculated, not measured: hours = rated Wh × efficiency ÷ (appliance W × duty); assumptions on How we verify. “Unlikely to start”: start-up surge exceeds the stated surge rating.
What the DELTA 3 changes
Of the 16 published specifications we compare, EcoFlow changed 7 (DELTA 2 → DELTA 3); 8 are the same on paper.
- Surge output: 2,700 W → 3,600 W
- Full recharge from wall: 80 min → 56 min
- Rated cycle life: 3,000+ cycles to 80% → 4,000 cycles to 80%+
- UPS switchover: 30 ms → <10 ms
- Expandable: Yes, up to 3,000 Wh → Yes, up to 5,000 Wh
- Max AC charging input: 1,200 W → 1,500 W
- Weight: about 27 lb → about 27.6 lb
EcoFlow states 1 more only for one of the two: Manufacturer list price when checked (Manufacturer does not state → $699).
Not listed as changes: stated noise (the two figures are not measured on the same basis; see the notes).
What the differences mean
Surge headroom. The DELTA 3’s stated 3,600 W surge is 2.00× its 1,800 W continuous rating, against 1.50× for the DELTA 2 (2,700 W over 1,800 W). Headroom is what starts a compressor or a pump; see the refrigerator and sump rows in the runtime table.
Recharge. Both store the same 1,024 Wh; the DELTA 3 refills that capacity in less time (56 min vs 80 min).
Cycle rating. The DELTA 3 is rated for 4,000 cycles against 3,000 for the DELTA 2, both to the same remaining-capacity threshold — otherwise we would not compare them. At one full cycle a week the difference is measured in years, not months; at occasional outage use neither limit is reached.
Which one, and for whom
On normalized measures the DELTA 3 leads on surge headroom (2.00× vs 1.50×), recharge rate (18.3 Wh/min vs 12.8 Wh/min) and rated cycle life (4,000 vs 3,000). The DELTA 2 does not lead on any decided measure. The deciding figure is the one your own outage will test first:
- CPAP overnight. Switchover: DELTA 2 30 ms, DELTA 3 under 10 ms. A 40 W CPAP runs roughly 18–21 hr on the DELTA 2 and 18–21 hr on the DELTA 3. Both run the night; on published figures the DELTA 3 switches at least as fast (under 10 ms vs 30 ms).
- Keeping a refrigerator cold. The compressor has to start before hours matter. The DELTA 2 states a 2,700 W surge rating; the DELTA 3 states a 3,600 W surge rating. A full-size refrigerator needs about 900 W to start.
- A multi-day outage with a generator or solar to recharge from. Full recharge: DELTA 2 80 min, DELTA 3 56 min. The faster unit spends less generator fuel per charge.
Questions people ask about these two
From 16 search suggestions that name both units; answers use only the figures on this page.
Which is lighter, the DELTA 2 or the DELTA 3?
DELTA 2 27 lb, DELTA 3 27.6 lb (manufacturer figures); per watt-hour carried, 37.9 vs 37.1 Wh/lb.
Also searched alongside this pair: “ecoflow delta 2 vs delta 3”, “ecoflow delta 2 vs delta 3 classic”, “ecoflow delta 2 vs delta 3 air”, “ecoflow delta 2 vs delta 3 max”.
Check the current price
Links go to the exact base unit we compared, not a bundle. Amazon prices change daily.
We do not link the DELTA 2: we could not confirm a listing for the exact base unit, and we do not link a guess.
Buying a superseded model: what actually changes
Nothing in the table above changes because a model leaves the catalog. The cells, the inverter and the cycle rating are what they were. Three things do change.
- Price, and therefore cost per watt-hour. A superseded unit is only a bargain if its lower price beats the successor on cost per watt-hour and the successor’s advantages are ones you will not use. Compare against the successor’s figures (see our DELTA 3 and successor comparisons on the Comparisons page). If the successor’s surge or UPS figure is the one your outage tests, the discount is buying you the wrong unit cheaply.
- Warranty and support. The manufacturer states a 5-year warranty for the DELTA 2. Check with the retailer that the term runs from your purchase date, not the model’s launch date. How long firmware and app support continue for a retired model is not something we could verify from the manufacturer’s pages; if the app matters to you, ask before buying.
- Expansion batteries. If you expect to add capacity later, confirm the matching expansion battery is still sold. Successor batteries are not always backward-compatible.
Our rule: compare the discounted price against the successor on cost per watt-hour first. If the superseded unit does not win there, the rest does not matter.
Related reading
A 1,024 Wh battery cannot do what a gasoline generator does — the runtime table shows a 1,500 W space heater emptying either unit in about 0.6 hr — but it also cannot poison a household. How often gasoline generators kill indoors — and how the official count keeps being revised — is documented in our CPSC revision matrix, and this page puts every verified unit on the same refrigerator scenario.
Other comparisons with these models
Sources and method
- EcoFlow DELTA 2: manufacturer product page, checked 2026-08-23.
- EcoFlow DELTA 3: manufacturer product page, checked 2026-08-23.
Published specifications only; no bench tests. Method: How we verify.
More: Comparisons.