Anker 521 PowerHouse vs Growatt VITA 550
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 $150 less. Whether that gap is worth closing depends on what you need to run.
- Growatt VITA 550 holds 110% more energy (538Wh vs 256Wh), so it runs the same load proportionally longer.
- Growatt VITA 550 has 900W more surge headroom (1200W vs 300W) — that decides whether a fridge, pump or AC compressor will actually start.
- Anker 521 PowerHouse is 9.4 lb lighter (8.2 lb vs 17.6 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 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
A tidy half-kWh unit with fast charging and a 1,200W surge that lets it start small appliances a 600W rating wouldn't suggest.
Best for: Campers who want fast charging and a bit of surge headroom at half a kWh.
Where it falls short:
- 538Wh is weekend-scale
- 3-year warranty
| Spec | Anker 521 PowerHouse | Growatt VITA 550 |
|---|---|---|
| Price | $249 | $399 |
| Capacity | 256 Wh | 538 Wh |
| Continuous output | 200 W | 600 W |
| Surge output | 300 W | 1200 W |
| Battery | LiFePO4 | LiFePO4 |
| Rated cycles | 3,000 | 3,000 |
| Weight (lighter wins) | 8.2 lb | 17.6 lb |
| Max solar | 100 W | 300 W |
| Recharge time (faster wins) | 2h 30m | 1h |
Runtime head-to-head
| Appliance | Anker 521 PowerHouse | Growatt VITA 550 |
|---|---|---|
| Refrigerator | ❌ | 7.6 hrs |
| Mini fridge | ❌ | 14.5 hrs |
| Chest freezer | ❌ | 5.7 hrs |
| CPAP machine | 5.4 hrs | 11.4 hrs |
| Sump pump | ❌ | ❌ |