EcoFlow DELTA Pro Ultra
#15 in Home backupFull review
A modular 6kWh home-backup system for buyers who need 240V output and plan to expand. Overkill for camping or short outages.
Amazon $4,199$4,199
The EcoFlow DELTA Pro Ultra is the better portable power station overall, rated 3.8 to 3.7. The EcoFlow DELTA Pro Ultra leads on AC output, solar input and features. The EcoFlow DELTA Pro wins on value and portability. The EcoFlow DELTA Pro costs $2,400 less ($1,799 vs $4,199).
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.
Which should you buy?
- Choose the EcoFlow DELTA Pro Ultra for AC output (7,200 W continuous AC vs 3,600 W continuous AC), solar input (5,600 W max solar input vs 1,600 W max solar input) and features (UPS (0 ms), expandable, 100 W USB-C, app vs expandable, 100 W USB-C, app).
- Choose the EcoFlow DELTA Pro for value ($0.50 per rated Wh vs $0.68 per rated Wh) and portability (80 Wh per kg (99 lb (45 kg)) vs 75 Wh per kg (181.8 lb (82.4 kg))).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every home backup portable power station; a clear win is highlighted. How we rank explains each one.
| Factor weight | EcoFlow DELTA Pro Ultra | EcoFlow DELTA Pro |
|---|---|---|
| Overall rating | 3.8/5 | 3.7/5 |
| Value 25% | 41 $0.68 per rated Wh | 69 $0.50 per rated Wh |
| Tested capacity 15% | 50 not yet independently tested (neutral score used) | 66 84% of rated capacity delivered (2 tests) |
| Battery life 15% | 96 LiFePO4, 3,500 cycles, 5-year warranty | 96 LiFePO4, 3,500 cycles, 5-year warranty |
| AC output 15% | 100 7,200 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% | 54 75 Wh per kg (181.8 lb (82.4 kg)) | 64 80 Wh per kg (99 lb (45 kg)) |
| Solar input 5% | 90 5,600 W max solar input | 35 1,600 W max solar input |
| Features 5% | 100 UPS (0 ms), expandable, 100 W USB-C, app | 65 expandable, 100 W USB-C, app |
Independent capacity tests
EcoFlow DELTA Pro Ultra
No independent test published yet.
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 Pro Ultra | EcoFlow DELTA Pro | |
|---|---|---|
| Battery | ||
| Rated capacity | 6,144 Wh | 3,600 Wh |
| Tested usable capacity | - | 3,042 Wh (84%) |
| Chemistry | LiFePO4 | LiFePO4 |
| Cycle life | 3,500 to 80% | 3,500 to 80% (6,500 to 50%) |
| Expandable | Yes, up to 30,000 Wh | Yes, up to 25,000 Wh |
| Output | ||
| AC output | 7,200 W (10,800 W surge) | 3,600 W (7,200 W surge) |
| Boost mode (resistive loads) | - | 4,500 W |
| AC outlets | 6 total | 5 total |
| 120V 20A outlets (NEMA 5-20R) | 4 | 4 |
| RV 30A outlet (TT-30R) | 1 | 1 |
| 120/240V 30A twist-lock (NEMA L14-30R) | 1 | - |
| AC waveform | Pure sine wave, 120/240V split phase | Pure sine wave |
| USB-C ports | 2 (up to 100 W each) | 2 (up to 100 W each) |
| USB-A ports | 2 | 4 |
| 12 V car outlet | - | Yes |
| DC5521 ports | 0 | 2 |
| UPS / pass-through | Yes (0 ms switchover) | - |
| Charging | ||
| AC charging | - | 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 | 5,600 W | 1,600 W |
| Solar input voltage | High-voltage 80-450V (4000W) and low-voltage 30-150V (1600W) | 11-150V, 15A |
| Car charging | - | 96 W |
| Build | ||
| Weight | 181.8 lb (82.4 kg) | 99 lb (45 kg) |
| Dimensions | Inverter 27.2 x 18.9 x 8.4 in; battery 26 x 18 x 8 in | 25 x 11.2 x 16.4 in |
| App | EcoFlow app (Bluetooth, Wi-Fi and 4G) | EcoFlow app (Wi-Fi and Bluetooth) |
| Warranty | 5 years | 5 years |
| Released | 2024-01 | 2021 |