EcoFlow DELTA 2 Max
#9 in LargeFull review
A proven 2kWh LiFePO4 station for home backup and RV trips with plenty of outlets. It costs less than the DELTA 3 Max Plus but has slower switchover and less output.
Amazon $1,049$1,049
The EcoFlow DELTA 2 Max rates 4.1 among large portable power stations; the EcoFlow DELTA 3 Ultra rates 3.7 among home backup ones. The EcoFlow DELTA 2 Max costs $300 less ($1,049 vs $1,349).
EcoFlow DELTA 3 Ultra
#22 in Home backupFull review
A wheeled 3kWh station for home backup or RV use at a lower price than its expandable sibling. Buy it if 3kWh is enough and you charge mostly from the wall.
Amazon $1,699 EcoFlow $1,349$1,349
Prices were last checked October 24, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Scores side by side
These two sit in different size classes (large and home backup), and each is scored against the reference points for its own class, so a rating says how well each does among its own size peers. How we rank explains each factor.
| Factor weight | EcoFlow DELTA 2 Max | EcoFlow DELTA 3 Ultra |
|---|---|---|
| Overall rating | 4.1/5 | 3.7/5 |
| Value 25% | 67 $0.51 per rated Wh | 79 $0.44 per rated Wh |
| Tested capacity 15% | 81 88% of rated capacity delivered (1 test) | 55 82% of rated capacity delivered (1 test) |
| Battery life 15% | 91 LiFePO4, 3,000 cycles, 5-year warranty | 70 LiFePO4, 5-year warranty |
| AC output 15% | 54 2,400 W continuous AC | 37 3,600 W continuous AC |
| Charging speed 10% | 84 0-100% on AC in 1 h 20 min | 50 full AC charge time not published (neutral score used) |
| Portability 10% | 80 89 Wh per kg (50 lb (23 kg)) | 89 94 Wh per kg (72.1 lb (32.7 kg)) |
| Solar input 5% | 40 1,000 W max solar input | 13 800 W max solar input |
| Features 5% | 100 UPS (30 ms), expandable, 100 W USB-C, app | 75 UPS (10 ms), 140 W USB-C, app |
Independent capacity tests
EcoFlow DELTA 2 Max
| Tested by | Usable AC energy | Of rated | Conditions |
|---|---|---|---|
| StorageReview | 1,800 Wh | 88% | AC discharge at a 350W load. Recharge took 2,370 Wh from the wall. |
EcoFlow DELTA 3 Ultra
| Tested by | Usable AC energy | Of rated | Conditions |
|---|---|---|---|
| The Solar Lab | - | 82% | Efficiency test (load not stated in the review). Measured AC recharge 0-100% in 2 h from a standard household outlet. |
Specifications
| EcoFlow DELTA 2 Max | EcoFlow DELTA 3 Ultra | |
|---|---|---|
| Battery | ||
| Rated capacity | 2,048 Wh | 3,072 Wh |
| Tested usable capacity | 1,800 Wh (88%) | 2,519 Wh (82%) |
| Chemistry | LiFePO4 | LiFePO4 |
| Cycle life | 3,000 to 80% | - |
| Expandable | Yes, up to 6,144 Wh | No |
| Output | ||
| AC output | 2,400 W (4,800 W surge) | 3,600 W (7,200 W surge) |
| Boost mode (resistive loads) | 3,400 W | 4,600 W |
| AC outlets | 6 total | 5 total |
| 120V 20A outlets (NEMA 5-20R) | 6 | 4 |
| RV 30A outlet (TT-30R) | - | 1 |
| AC waveform | Pure sine wave | Pure sine wave |
| USB-C ports | 2 (up to 100 W each) | 3 (up to 140 W each) |
| USB-A ports | 4 | 1 |
| 12 V car outlet | Yes | Yes |
| DC5521 ports | 2 | 0 |
| UPS / pass-through | Yes (30 ms switchover) | Yes (10 ms switchover) |
| Charging | ||
| AC charging | 1,800 W | 1,800 W |
| Full AC charge time | 1 h 20 min (0-80% in 1.1 h on AC alone; 43 min with AC and solar together) | - |
| Max solar input | 1,000 W | 800 W |
| Solar input voltage | 11-60V, 15A (2 inputs, 500W each) | - |
| Car charging | 96 W | - |
| Build | ||
| Weight | 50 lb (23 kg) | 72.1 lb (32.7 kg) |
| Dimensions | 19.6 x 9.5 x 12 in | 626 x 328 x 395 mm |
| App | EcoFlow app (Wi-Fi and Bluetooth) | EcoFlow app (Wi-Fi and Bluetooth) |
| Warranty | 5 years | 5 years |
| Released | 2023-05 | 2025-09 |