Which portable power stations can run a sump pump

How much power a sump pump draws

Liberty and Zoeller list amps on their spec sheets, not watts. Amps times the 115 V supply gives volt-amperes (VA). A motor's real watts are lower than its VA by its power factor, which neither maker prints. This page counts each VA figure as watts, so its runtimes are on the short side.

• 1/3 HP, Liberty 257: 5.2 A full load and 8 A locked rotor, per Liberty's 250 Series sheet. That is 598 VA running and 920 VA starting.
• 1/2 HP, Liberty 287: 8.0 A full load and 23 A locked rotor, per Liberty's 280 Series sheet, or 920 VA running and 2,645 VA starting.
• 1/2 HP, Zoeller M98: 9.4 A, or 1,081 VA running, per Zoeller's FM0532 sheet. Zoeller gives no locked-rotor figure.
• 3/10 HP, Zoeller M53: 9.7 A, or 1,116 VA running, on the same sheet, also with no locked-rotor figure.

Locked rotor is the current a motor draws for a moment as it starts. The two Zoeller pumps show that horsepower is a poor guide to the draw: the 3/10 HP M53 draws more than the 1/2 HP M98. Read the amps on your own pump's label and multiply by 115.

Start-up decides which stations can run it

A station can list two output ratings: continuous watts, and a peak (surge) figure for the moment a motor starts. The 1/2 HP Liberty 287 needs 920 W running and 2,645 W at start-up.

• Peak covers it: every EcoFlow DELTA model (3,600 W surge and up), Anker SOLIX C1000 Gen 2 and C2000 Gen 2, Jackery Explorer 1000 v2, 1500 v2 and 2000 v2, BLUETTI Elite 100 V2 and AC180 (2,700 W), both Dabbsson models and the FOSSiBOT F2400.
• Continuous output covers it: DJI Power 2000 (3,000 W) and Anker SOLIX F3800 Plus (6,000 W), which list no surge rating.
• Start-up too high: DJI Power 1000 V2 (2,400 W, no surge rating), BLUETTI Elite 200 V2 (2,600 W; its 3,900 W Lifting Power is a boost mode, not a surge rating) and FOSSiBOT F1800 (1,800 W; its 2,400 W mode is for resistive loads).
• Running draw too high: every station under 1,024 Wh, rated 700 W or less.

The 1/3 HP Liberty 257 starts at 920 W, which every station from 1,004.8 Wh up covers, as does the 286 Wh EcoFlow RIVER 3 Plus (1,200 W surge). Zoeller gives no starting figure, so the table checks the M98 and M53 on running watts only. Ask Zoeller for your pump's starting current.

Hours of pumping, not hours on the clock

The table shows how long each station runs a pump that never stops. A pump with a float switch runs only while it empties the pit, then waits for the water to rise again, so the battery lasts longer on the clock than the table's figures.

How much pumping you need in a day depends on how fast water enters your pit, and that changes with the rain. The sizing tool starts at 30 minutes of pumping a day. That figure is our assumption, not a maker's, so change it to match your pit: in heavy rain, time how long the pump runs each time it switches on, and count how many times it switches on in an hour.

Hours of pumping from the 1/2 HP Liberty 287:

• 1,024 Wh station that can start it, such as the EcoFlow DELTA 3: 54 minutes
• Jackery Explorer 1500 v2, 1,536 Wh: 1.3 hours
• 2,048 Wh station, such as the Anker SOLIX C2000 Gen 2: 1.8 hours
• EcoFlow DELTA Pro 3, 4,096 Wh: 3.6 hours

The 1/3 HP Liberty 257 gets 1.4 hours from 1,024 Wh and 2.7 hours from 2,048 Wh.

Worked example: a day without power

The sizing tool on this page starts with an outage day for a 1/2 HP pump:

• Liberty 287 sump pump, 30 minutes of pumping
• Wi-Fi router, 24 hours
• One LED bulb, 5 hours
• Two phone charges

That list uses 999 Wh in a day. The total includes the inverter's own draw for all 24 hours, because the AC output stays on for the router and the pump: 15 W on a station of 1,000 to 1,499 Wh, from Jackery's calculator figures, applied to every brand. The runtime formula counts 82% of rated capacity as usable, so you need a station rated at 1,218 Wh or more.

A 1,024 Wh station that can start the pump covers 84% of that day, and the 1,152 Wh BLUETTI AC180 covers 95%. The Jackery Explorer 1500 v2 (1,536 Wh) covers 1.18 days, a 2,048 Wh station such as the Anker SOLIX C2000 Gen 2 covers 1.57 days, and the EcoFlow DELTA Pro 3 covers 3.14 days.

More rain, a different pump or a refrigerator

Each line below changes one thing in the worked example:

• 1 hour of pumping: the day needs a station rated at 1,867 Wh. A 2,048 Wh station covers 1.10 days.
• 2 hours of pumping: 2,989 Wh. Only the Anker SOLIX F3800 Plus (1.28 days) and the EcoFlow DELTA Pro 3 (1.37 days) cover it.
• The 1/3 HP Liberty 257 in place of the 1/2 HP: 1,022 Wh. Every 1,024 Wh station covers it (1.00 days), including the DJI Power 1000 V2 and FOSSiBOT F1800, which cannot start the 1/2 HP pump.
• The 1/2 HP Zoeller M98 in place of the Liberty: 1,316 Wh. The Jackery Explorer 1500 v2 covers 1.09 days.
• Add a 21 cu ft refrigerator for 24 hours: 2,638 Wh. Only the F3800 Plus (1.46 days) and the DELTA Pro 3 (1.55 days) cover it.

The tool counts every other AC load on your list as running when the pump starts. With the refrigerator added, the start-up total is 2,703 W, more than the BLUETTI AC180's 2,700 W surge. The refrigerator's 45.5 W is a daily average, and this site has no start-up figure for it, so the real total at that moment can be higher. Try your own list in the sizing tool.

How to connect the pump in an outage

Plug the pump's own cord straight into one of the station's AC outlets. Leave the station's AC output switched on: a float switch can start the pump only when its outlet has power, so if your station can turn AC off when nothing draws power, turn that setting off.

If you keep the station plugged into the wall with the pump plugged into the station, a station with a UPS spec switches the pump to battery when the grid fails. Anker lists 10 ms for the SOLIX C2000 Gen 2, Jackery 10 ms for the Explorer 1500 v2, EcoFlow 10 ms for the DELTA Pro 3 and Dabbsson 15 ms (EPS) for the DBS1000 Pro.

A hard-wired pump has no plug to move, so it needs a transfer switch or power inlet installed by a licensed electrician. Never back-feed a house by plugging a station into a wall outlet.

A battery-backup sump pump is a different product

Battery-backup sump pump systems are a different product from a portable power station. This site has no figures for them, so it cannot compare their runtimes with the table above.

A portable power station is a battery with its own outlets, so the same unit can run other things in an outage. The Anker SOLIX C2000 Gen 2 runs each of these on its own for:

• 1/2 HP Liberty 287 sump pump: 1.8 hours of pumping
• 21 cu ft Whirlpool top-freezer refrigerator: 26 hours
• ResMed AirSense 11 CPAP: 23 hours
• eero 6+ Wi-Fi router: 3.1 days

For a CPAP, check with your doctor or equipment supplier about running it on battery power. There is more on sizing for a whole outage on the home backup page.

More ways to size a power station

• What size power station you need for a power outage
• What size power station you need for a refrigerator
• What size power station runs a gas furnace in an outage