The Best Power Station for a Sump Pump
The spec that decides this is surge rating, not battery size. A 1/2 HP pump can ask for 2,000W extra at the instant it starts.
At a glance
Quick picks
Tap any row to jump to the full write-up. Weight is a column here because it is the spec that decides whether you actually carry the thing.
| # | Product | Best for | Capacity · Weight | Price |
|---|---|---|---|---|
| 1 |  Anker SOLIX C1000 Gen 2 | Best for a 1/3 or 1/2 HP pump | 1,024Wh 24.9 lb | Check price |
| 2 |  EcoFlow DELTA 2 Max | Best for a long storm outage | 2,048Wh 50.7 lb | Check price |
| 3 |  Anker SOLIX F3800 | Best for a large pump or a backed-up circuit | 3,840Wh 132.3 lb | Check price |
For most homes the right answer is the [Anker SOLIX C1000 Gen 2](/reviews/anker-solix-c1000-gen-2): 2,000W of continuous output, a 3,000W peak and a 10 ms UPS switchover. A sump pump is not a big load in watt-hour terms — it is a brutal one for a fraction of a second at start-up, and it needs the mains to be replaced fast enough that an unattended basement never notices. Those two specs, not the battery size, are what decide whether a power station is useful here.
If the storm that causes the outage is the same storm filling the pit, you also need runtime, and the EcoFlow DELTA 2 Max doubles the battery to 2,048Wh with expansion to 6kWh. If the pump is 3/4 HP or larger, or you want the whole circuit backed up rather than one appliance, the Anker SOLIX F3800 and its 6,000W is the only honest recommendation here.
What a sump pump actually draws
Anker's own backup-generator guide publishes the figures most usefully: a 1/3 HP pump draws about 5.2 amps at 115 volts, which is roughly 600 running watts, and a 1/2 HP model often lands around 7.3 amps, or about 840 running watts. It also states the rule that matters: starting watts for motor-driven equipment are typically about twice the running watts, and for a 1/2 HP pump it quotes roughly 2,000+ additional starting watts on top of a 1,050W running figure.
Published ranges across pump sizes land at roughly 400-800W running and 800-1,500W starting for a 1/3 HP pump, and 600-1,000W running with 1,200-2,000W starting for a 1/2 HP. Those brackets are wide because pump design varies; the number on your own pump's label is the one that counts, and it is worth going down and reading it before you buy anything.
Why switchover time matters more here than anywhere else
Most home backup is attended: the lights go out, you walk over and plug the fridge in. A sump pump is the opposite. It fails while you are asleep or out, and the consequence is water rather than a warm fridge. That makes automatic transfer the whole point of using a power station rather than a generator.
Anker's guide on using a power station as a UPS is clear that pass-through charging and UPS mode are not the same thing: pass-through lets a unit recharge while running devices, while genuine UPS behavior additionally requires a fast battery switchover during an outage. It warns that a 20-50 ms delay can shut sensitive equipment down. A pump motor is more tolerant than a desktop PC, but the principle holds — the shorter the gap, the less you are relying on luck. Pass-through charging explained covers the distinction in full, and using a power station as a UPS for a router applies it to the easier case.
The comparison table
| Unit | AC continuous | Surge | Capacity | UPS switchover |
|---|---|---|---|---|
| Anker SOLIX C1000 Gen 2 | 2,000W | 3,000W | 1,024Wh | 10 ms |
| EcoFlow DELTA 2 Max | 2,400W | Not published | 2,048Wh | Under 20 ms |
| Anker SOLIX F3800 | 6,000W | 9,000W | 3,840Wh | Not published |
What to look for
Surge rating at least 1.5x your pump's published starting watts. For a 1/2 HP pump quoted at 2,000W starting, that means 3,000W of surge, which is where the units on this page start.
Continuous output comfortably above the running draw, because the pump will run for minutes at a time, not seconds, during real rain.
A published switchover figure in the tens of milliseconds, and the ability to sit permanently plugged in. A backup that has to be found and connected is not a sump pump backup.
Enough capacity for the outage you actually get. Storm outages run for hours, and the pump's duty cycle rises exactly when the power is most likely to be off. Our arithmetic above assumes 10% — if your pit fills faster than that, double the battery.
Somewhere cool and ventilated to put it. Anker's guidance notes that both charging and inverting generate heat and that good ventilation is essential. A basement corner is fine; a sealed cupboard next to the pit is not.
What this cannot do, honestly
A power station is not a substitute for a dedicated battery backup pump or a water-powered backup if your basement floods catastrophically and often. What it is good at is covering the common case — a storm outage of a few hours, a pump that cycles intermittently, and nobody home. For a multi-day outage with a hard-working pump you are into the F3800 class with expansion batteries, or a generator. Power station vs gas generator sets out that trade without hedging.
Every figure on this page came from a manufacturer's published specification or Anker's published sizing guidance, linked at the foot. We have not tested these units on a pump. How we choose explains the method and its limits, and what size power station for a power outage does the whole-house version of this arithmetic.
The picks in full
1. Best for a 1/3 or 1/2 HP pump
Anker SOLIX C1000 Gen 2
- 1,024Wh
- LiFePO4 (InfiniPower LFP)
- 2,000W continuous / 3,000W surge
- 24.9 lb
- 600W
- 80% capacity after 4,000 cycles
- Full in 49 min (UltraFast, 1,600W max input)
- 5 years
2,000W continuous with a 3,000W peak clears a 1/2 HP pump's published 2,000W starting demand with 50% margin, which is the amount of headroom you want on a load that only ever starts when it matters. That alone would make it the pick.
The 10 ms switchover is the other half. It is the fastest figure in our whole set, and for an appliance that fails unattended it is worth more than extra battery. Keep it plugged in permanently with the pump connected and the handover happens whether you are there or not.
1,024Wh is the honest limitation. At a 10% duty cycle that is about twelve hours of a 1/3 HP pump; at 20% it is six. The Gen 2 also dropped expandability — the previous C1000 takes a second 1,056Wh pack and this one does not — so if a long outage is your real worry, this is not the unit to grow with.
Reasons to buy
- 3,000W peak clears a 1/2 HP pump's published starting demand with margin
- 2,000W continuous, comfortably above any single-pump running draw
- 10 ms UPS switchover, the fastest in our set
- 49-minute full recharge means a brief mains window refills it
- 80% capacity after 4,000 cycles; 600W solar input if the outage runs long
Reasons to avoid
- 1,024Wh limits you to roughly a twelve-hour outage at a 10% duty cycle
- Not expandable, unlike the previous C1000 generation
- Two AC sockets only
- Fast charging runs it warm, so ventilation matters in a basement
Buy it if: a standard 1/3 or 1/2 HP pedestal or submersible pump, and outages measured in hours.
Skip it if: your outages run for days, or the pump is 3/4 HP or larger.
2. Best for a long storm outage
EcoFlow DELTA 2 Max
- 2,048Wh
- LFP (LiFePO4)
- 2,400W continuous
- 50.7 lb
- 1000W
- 3,000 cycles to 80% capacity
- 2.3 hr; 800W car/alternator charging
- 5 years
2,048Wh doubles the runtime problem away. At a 10% pump duty cycle that is a day of a 1/3 HP pump with capacity left for a fridge and a router, and expansion from 2kWh to 6kWh means a genuinely multi-day storm is a purchase decision rather than a dead end.
2,400W of continuous output is the highest here short of the F3800, with 3,400W available through X-Boost for resistive loads, and EcoFlow publishes an under-20 ms UPS switchover. The 1,000W solar input ceiling matters more than it sounds for this use: if the outage outlasts the battery, a panel on the lawn the morning after the storm is a real refill route.
Two things to weigh. EcoFlow publishes no surge figure for this model on either its shop page or ecoflow.com/us, which for a pump is the one number you most want — size against the 2,400W continuous figure and treat the margin as unknown. And at 50.7 lb it is a two-handed lift, so decide where it lives before it arrives.
Reasons to buy
- 2,048Wh, expandable to 6kWh for multi-day storms
- 2,400W continuous; 3,400W through X-Boost
- Under-20 ms UPS switchover
- 1,000W solar input for refilling after the storm passes
- 2.3-hour wall recharge; 15 outputs including six AC sockets
Reasons to avoid
- EcoFlow publishes no surge figure for this model
- 50.7 lb — positioned once, not carried
- 3,000 cycles to 80%, shorter than the Anker's 4,000
- No published dimensions, so plan the space generously
Buy it if: storm-season outages that run all day, with a fridge and a router to cover as well as the pump.
Skip it if: you need a published surge figure to size against confidently.
3. Best for a large pump or a backed-up circuit
Anker SOLIX F3800
- 3,840Wh
- LiFePO4 (LFP)
- 6,000W continuous / 9,000W surge
- 132.3 lb
- 2400W
- 3,000+ cycles
- 1,800W max AC input
- 5 years
6,000W continuous and 9,000W surge removes the surge question entirely. A 3/4 HP or 1 HP pump, a pump plus a well pump, or a pump on a circuit shared with other loads all fit inside that envelope with room to spare, and nothing else here comes close.
3,840Wh with expansion to six batteries and 53.8 kWh is the capacity to ride out a multi-day outage with the pump cycling hard, and the 240V NEMA 14-50 and L14-30 outlets mean this can be wired to feed circuits through a transfer switch rather than a single extension cord. 2,400W of solar input is the highest ceiling in our set.
132.3 lb including wheels is the honest cost. It rolls across a flat basement floor and it does not go down stairs without help, which for many houses is the end of the conversation. Anker also does not publish a UPS switchover figure for this model, so confirm its behavior before relying on it unattended.
Reasons to buy
- 9,000W surge and 6,000W continuous — no pump will trouble it
- 3,840Wh, expandable to 53.8 kWh
- 240V NEMA 14-50 and L14-30 for circuit-level backup
- 2,400W solar input, the highest ceiling here
- Six 20A NEMA 5-20 sockets; 3,000+ cycles; 5-year warranty
Reasons to avoid
- 132.3 lb and wheeled — getting it to a basement is the real problem
- No published UPS switchover figure for this model
- 1,800W maximum AC input is modest for the battery size
- Far more unit than a single 1/3 HP pump needs
Buy it if: a 3/4 HP or larger pump, or a house where you want whole-circuit backup rather than one plug.
Skip it if: the unit has to be carried downstairs. It is a fixture, not a portable.
Questions