EcoFlow RIVER 3 vs Anker 521 PowerHouse
Side-by-side on the specs that decide it — surge, capacity, runtime and price.
Both models' specs verified against manufacturer listings · Last updated
The short answer
EcoFlow RIVER 3 costs $10 less. Whether that gap is worth closing depends on what you need to run.
- Anker 521 PowerHouse holds 4% more energy (256Wh vs 245Wh), so it runs the same load proportionally longer.
- EcoFlow RIVER 3 has 300W more surge headroom (600W vs 300W) — that decides whether a fridge, pump or AC compressor will actually start.
- EcoFlow RIVER 3 is 0.4 lb lighter (7.8 lb vs 8.2 lb).
Neither of these will start a sump pump or well pump — both surge below the ~3,400W those motors need. If home backup with pumps is your use case, look at higher-surge models instead of either of these.
A glorified power bank with AC outlets — and that's fine if that's what you need. 245Wh runs devices, not appliances.
Best for: Weekend campers charging phones, cameras and a laptop.
Where it falls short:
- 300W output rules out anything with a heating element
- No expansion path
A pocket-scale LiFePO4 unit for keeping devices alive. 200W of output means it's a charger, not an appliance station.
Best for: Travelers and campers topping up phones, cameras and a laptop.
Where it falls short:
- 200W output runs devices only
- 256Wh is small
| Spec | EcoFlow RIVER 3 | Anker 521 PowerHouse |
|---|---|---|
| Price | $239 | $249 |
| Capacity | 245 Wh | 256 Wh |
| Continuous output | 300 W | 200 W |
| Surge output | 600 W | 300 W |
| Battery | LiFePO4 | LiFePO4 |
| Rated cycles | 3,000 | 3,000 |
| Weight (lighter wins) | 7.8 lb | 8.2 lb |
| Max solar | 110 W | 100 W |
| Recharge time (faster wins) | 1h | 2h 30m |
Runtime head-to-head
| Appliance | EcoFlow RIVER 3 | Anker 521 PowerHouse |
|---|---|---|
| Refrigerator | ❌ | ❌ |
| Mini fridge | 6.6 hrs | ❌ |
| Chest freezer | ❌ | ❌ |
| CPAP machine | 5.2 hrs | 5.4 hrs |
| Sump pump | ❌ | ❌ |