Anker 555 PowerHouse 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 $450 less. Whether that gap is worth closing depends on what you need to run.
- Anker 555 PowerHouse holds 300% more energy (1024Wh vs 256Wh), so it runs the same load proportionally longer.
- Anker 555 PowerHouse has 1200W more surge headroom (1500W vs 300W) — that decides whether a fridge, pump or AC compressor will actually start.
- Anker 521 PowerHouse is 21.7 lb lighter (8.2 lb vs 29.9 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 1kWh unit whose 1,000W output and slow charging show its age — the newer, cheaper Anker C1000 beats it on nearly every axis.
Best for: Only worth it steeply discounted against the C1000.
Where it falls short:
- 1,500W surge is low
- 200W solar input and a slow 138-minute recharge
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 | Anker 555 PowerHouse | Anker 521 PowerHouse |
|---|---|---|
| Price | $699 | $249 |
| Capacity | 1024 Wh | 256 Wh |
| Continuous output | 1000 W | 200 W |
| Surge output | 1500 W | 300 W |
| Battery | LiFePO4 | LiFePO4 |
| Rated cycles | 3,000 | 3,000 |
| Weight (lighter wins) | 29.9 lb | 8.2 lb |
| Max solar | 200 W | 100 W |
| Recharge time (faster wins) | 2h 18m | 2h 30m |
Runtime head-to-head
| Appliance | Anker 555 PowerHouse | Anker 521 PowerHouse |
|---|---|---|
| Refrigerator | 14.5 hrs | ❌ |
| Mini fridge | 27.6 hrs | ❌ |
| Chest freezer | 10.9 hrs | ❌ |
| CPAP machine | 21.8 hrs | 5.4 hrs |
| Sump pump | ❌ | ❌ |