EcoFlow DELTA Pro Ultra
#13 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 EcoFlow $4,199$4,199
The EcoFlow DELTA Pro Ultra and the EcoFlow DELTA Pro 3 are evenly matched, rated 3.8 and 3.8. The EcoFlow DELTA Pro Ultra leads on AC output and solar input. The EcoFlow DELTA Pro 3 wins on portability. The EcoFlow DELTA Pro 3 costs $1,400 less ($2,799 vs $4,199).
EcoFlow DELTA Pro 3
#15 in Home backupFull review
For households that want a single wheeled unit able to back up 240V circuits and expand toward whole-home capacity.
Amazon $2,799 EcoFlow $2,799$2,799
Prices were last checked October 20, 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 4,000 W continuous AC) and solar input (5,600 W max solar input vs 2,600 W max solar input).
- Choose the EcoFlow DELTA Pro 3 for portability (80 Wh per kg (113.5 lb (51.5 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 3 |
|---|---|---|
| Overall rating | 3.8/5 | 3.8/5 |
| Value 25% | 41 $0.68 per rated Wh | 41 $0.68 per rated Wh |
| Tested capacity 15% | 50 not yet independently tested (neutral score used) | 100 93% of rated capacity delivered (1 test) |
| Battery life 15% | 96 LiFePO4, 3,500 cycles, 5-year warranty | 100 LiFePO4, 4,000 cycles, 5-year warranty |
| AC output 15% | 100 7,200 W continuous AC | 46 4,000 W continuous AC |
| Charging speed 10% | 50 full AC charge time not published (neutral score used) | 50 full AC charge time not published (neutral score used) |
| Portability 10% | 54 75 Wh per kg (181.8 lb (82.4 kg)) | 63 80 Wh per kg (113.5 lb (51.5 kg)) |
| Solar input 5% | 90 5,600 W max solar input | 57 2,600 W max solar input |
| Features 5% | 100 UPS (0 ms), expandable, 100 W USB-C, app | 100 UPS (10 ms), expandable, 100 W USB-C, app |
Independent capacity tests
EcoFlow DELTA Pro Ultra
No independent test published yet.
EcoFlow DELTA Pro 3
| Tested by | Usable AC energy | Of rated | Conditions |
|---|---|---|---|
| OutdoorGearLab | 3,790 Wh | 92.5% | Full-discharge AC test; OutdoorGearLab states over 93%, 3790/4096 works out to 92.5%. Recharged from empty in about 3.2 h at about 1600W peak. |
Specifications
| EcoFlow DELTA Pro Ultra | EcoFlow DELTA Pro 3 | |
|---|---|---|
| Battery | ||
| Rated capacity | 6,144 Wh | 4,096 Wh |
| Tested usable capacity | - | 3,790 Wh (93%) |
| Chemistry | LiFePO4 | LiFePO4 |
| Cycle life | 3,500 to 80% | 4,000 to 80% |
| Expandable | Yes, up to 30,000 Wh | Yes, up to 12,000 Wh |
| Output | ||
| AC output | 7,200 W (10,800 W surge) | 4,000 W (8,000 W surge) |
| Boost mode (resistive loads) | - | 6,000 W |
| AC outlets | 6 total | 7 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 | 1 |
| 240V 20A outlet (NEMA 6-20R) | - | 1 |
| AC waveform | Pure sine wave, 120/240V split phase | - |
| USB-C ports | 2 (up to 100 W each) | 2 (up to 100 W each) |
| USB-A ports | 2 | 2 |
| DC5521 ports | - | 1 |
| UPS / pass-through | Yes (0 ms switchover) | Yes (10 ms switchover) |
| Charging | ||
| AC charging | - | 1,800 W |
| Max solar input | 5,600 W | 2,600 W |
| Solar input voltage | High-voltage 80-450V (4000W) and low-voltage 30-150V (1600W) | HV 30-150V (1600W) + LV 11-60V (1000W) |
| Build | ||
| Weight | 181.8 lb (82.4 kg) | 113.5 lb (51.5 kg) |
| Dimensions | Inverter 27.2 x 18.9 x 8.4 in; battery 26 x 18 x 8 in | 27.28 x 16.16 x 13.43 in |
| App | EcoFlow app (Bluetooth, Wi-Fi and 4G) | Wi-Fi + Bluetooth |
| Warranty | 5 years | 5 years |