EcoFlow DELTA 3 Max
#26 in LargeFull review
For buyers who want 2 kWh of fast-charging backup at a mid-range price and do not need heavy solar input.
Amazon $899$899
The EcoFlow DELTA 3 Max rates 3.7 among large portable power stations; the EcoFlow DELTA Pro rates 3.7 among home backup ones. The EcoFlow DELTA 3 Max costs $900 less ($899 vs $1,799).
EcoFlow DELTA Pro
#21 in Home backupFull review
A heavy 3.6kWh station built for home backup that can grow into a 25 kWh system. It still makes sense if you want that expansion path, but newer models give similar capacity for less.
Amazon $1,799$1,799
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 3 Max | EcoFlow DELTA Pro |
|---|---|---|
| Overall rating | 3.7/5 | 3.7/5 |
| Value 25% | 79 $0.44 per rated Wh | 69 $0.50 per rated Wh |
| Tested capacity 15% | 41 79% of rated capacity delivered (1 test) | 66 84% of rated capacity delivered (2 tests) |
| Battery life 15% | 70 LiFePO4, 5-year warranty | 96 LiFePO4, 3,500 cycles, 5-year warranty |
| AC output 15% | 54 2,400 W continuous AC | 37 3,600 W continuous AC |
| Charging speed 10% | 50 full AC charge time not published (neutral score used) | 41 0-100% on AC in 2 h 42 min |
| Portability 10% | 100 101 Wh per kg (44.8 lb (20.3 kg)) | 64 80 Wh per kg (99 lb (45 kg)) |
| Solar input 5% | 11 500 W max solar input | 35 1,600 W max solar input |
| Features 5% | 75 UPS (10 ms), 100 W USB-C, app | 65 expandable, 100 W USB-C, app |
Independent capacity tests
EcoFlow DELTA 3 Max
| Tested by | Usable AC energy | Of rated | Conditions |
|---|---|---|---|
| The Solar Lab | - | 79% | Efficiency test (load not stated in the review). Measured AC recharge 0-100% in 68 min; idle draw 27W. |
EcoFlow DELTA Pro
| Tested by | Usable AC energy | Of rated | Conditions |
|---|---|---|---|
| OutdoorGearLab | 3,060 Wh | 85% | AC discharge test; the review’s spec table lists 2,950 Wh. Measured AC recharge took a little over 2 hours. |
| The Solar Lab | - | 84% | AC discharge; load not specified. AC recharge took about 2 h 15 min; idle draw 21W. |
Specifications
| EcoFlow DELTA 3 Max | EcoFlow DELTA Pro | |
|---|---|---|
| Battery | ||
| Rated capacity | 2,048 Wh | 3,600 Wh |
| Tested usable capacity | 1,618 Wh (79%) | 3,042 Wh (84%) |
| Chemistry | LiFePO4 | LiFePO4 |
| Cycle life | - | 3,500 to 80% (6,500 to 50%) |
| Expandable | - | Yes, up to 25,000 Wh |
| Output | ||
| AC output | 2,400 W (4,800 W surge) | 3,600 W (7,200 W surge) |
| Boost mode (resistive loads) | 3,400 W | 4,500 W |
| AC outlets | 4 total | 5 total |
| 120V 20A outlets (NEMA 5-20R) | 4 | 4 |
| RV 30A outlet (TT-30R) | - | 1 |
| AC waveform | Pure sine wave | Pure sine wave |
| USB-C ports | 3 (up to 100 W each) | 2 (up to 100 W each) |
| USB-A ports | 1 | 4 |
| 12 V car outlet | Yes | Yes |
| DC5521 ports | 0 | 2 |
| UPS / pass-through | Yes (10 ms switchover) | - |
| Charging | ||
| AC charging | 1,800 W | 1,800 W |
| Full AC charge time | - | 2 h 42 min (2.7 h at 1800W on 120V; 1.8 h at 3000W on 240V) |
| Max solar input | 500 W | 1,600 W |
| Solar input voltage | - | 11-150V, 15A |
| Car charging | 96 W | 96 W |
| Build | ||
| Weight | 44.8 lb (20.3 kg) | 99 lb (45 kg) |
| Dimensions | 494 x 239 x 305 mm | 25 x 11.2 x 16.4 in |
| App | Wi-Fi + Bluetooth | EcoFlow app (Wi-Fi and Bluetooth) |
| Warranty | 5 years | 5 years |
| Released | 2025-09 | 2021 |