EcoFlow DELTA 2 Max 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
Anker 521 PowerHouse costs $1350 less. Whether that gap is worth closing depends on what you need to run.
- EcoFlow DELTA 2 Max holds 700% more energy (2048Wh vs 256Wh), so it runs the same load proportionally longer.
- EcoFlow DELTA 2 Max has 4500W more surge headroom (4800W vs 300W) — that decides whether a fridge, pump or AC compressor will actually start.
- Anker 521 PowerHouse is 41.8 lb lighter (8.2 lb vs 50 lb).
EcoFlow DELTA 2 Max
The surge sleeper. At 4800W it starts loads that stations twice its price can't — and most spec sheets bury that number behind the X-Boost figure.
Best for: Home backup where something with a compressor — fridge, freezer, window AC — has to start reliably.
Where it falls short:
- 50 lb is heavy for its capacity
- Marketing leads with the 3400W X-Boost number, which understates it
Anker 521 PowerHouse
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 DELTA 2 Max | Anker 521 PowerHouse |
|---|---|---|
| Price | $1599 | $249 |
| Capacity | 2048 Wh | 256 Wh |
| Continuous output | 2400 W | 200 W |
| Surge output | 4800 W | 300 W |
| Battery | LiFePO4 | LiFePO4 |
| Rated cycles | 3,000 | 3,000 |
| Weight (lighter wins) | 50 lb | 8.2 lb |
| Max solar | 1000 W | 100 W |
| Recharge time (faster wins) | 1h 30m | 2h 30m |
Runtime head-to-head
| Appliance | EcoFlow DELTA 2 Max | Anker 521 PowerHouse |
|---|---|---|
| Refrigerator | 29.0 hrs | ❌ |
| Mini fridge | 55.3 hrs | ❌ |
| Chest freezer | 21.8 hrs | ❌ |
| CPAP machine | 43.5 hrs | 5.4 hrs |
| Sump pump | 2.2 hrs | ❌ |