The EcoFlow DELTA Pro and the EcoFlow DELTA 3 Ultra are evenly matched, rated 3.7 and 3.7. The EcoFlow DELTA Pro leads on battery life, tested capacity and solar input. The EcoFlow DELTA 3 Ultra wins on portability, value and features. The EcoFlow DELTA 3 Ultra costs $450 less ($1,349 vs $1,799).
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 $1,799A 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 $1,349Prices 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.
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 | EcoFlow DELTA 3 Ultra |
|---|---|---|
| Overall rating | 3.7/5 | 3.7/5 |
| Value 25% | 69 $0.50 per rated Wh | 79 $0.44 per rated Wh |
| Tested capacity 15% | 66 84% of rated capacity delivered (2 tests) | 55 82% of rated capacity delivered (1 test) |
| Battery life 15% | 96 LiFePO4, 3,500 cycles, 5-year warranty | 70 LiFePO4, 5-year warranty |
| AC output 15% | 37 3,600 W continuous AC | 37 3,600 W continuous AC |
| Charging speed 10% | 41 0-100% on AC in 2 h 42 min | 50 full AC charge time not published (neutral score used) |
| Portability 10% | 64 80 Wh per kg (99 lb (45 kg)) | 89 94 Wh per kg (72.1 lb (32.7 kg)) |
| Solar input 5% | 35 1,600 W max solar input | 13 800 W max solar input |
| Features 5% | 65 expandable, 100 W USB-C, app | 75 UPS (10 ms), 140 W USB-C, app |
| 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. |
| 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. |
| EcoFlow DELTA Pro | EcoFlow DELTA 3 Ultra | |
|---|---|---|
| Battery | ||
| Rated capacity | 3,600 Wh | 3,072 Wh |
| Tested usable capacity | 3,042 Wh (84%) | 2,519 Wh (82%) |
| Chemistry | LiFePO4 | LiFePO4 |
| Cycle life | 3,500 to 80% (6,500 to 50%) | - |
| Expandable | Yes, up to 25,000 Wh | No |
| Output | ||
| AC output | 3,600 W (7,200 W surge) | 3,600 W (7,200 W surge) |
| Boost mode (resistive loads) | 4,500 W | 4,600 W |
| AC outlets | 5 total | 5 total |
| 120V 20A outlets (NEMA 5-20R) | 4 | 4 |
| RV 30A outlet (TT-30R) | 1 | 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 (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 | 1,600 W | 800 W |
| Solar input voltage | 11-150V, 15A | - |
| Car charging | 96 W | - |
| Build | ||
| Weight | 99 lb (45 kg) | 72.1 lb (32.7 kg) |
| Dimensions | 25 x 11.2 x 16.4 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 | 2021 | 2025-09 |
