The short answer: yes. A typical one-third horsepower sump pump draws about 800W while it runs, and it only runs for minutes in an hour. That is why the Jackery HomePower 3000, with its 3,072Wh battery and 3,600W output, keeps a pump going for about a day and a half of steady rain, or more than four days of light seepage.
The HomePower 3600 Plus and the Solar Generator 5000 Plus stretch that further. The honest caveat is that a sump pump is a different kind of load from a fridge or a CPAP, because how long the battery lasts depends on the weather, not on the pump. Here is how to work it out for your own basement.
Why a sump pump is an unusual load
A fridge cycles on and off in a steady pattern and a CPAP draws the same amount all night. A sump pump does neither. It sits idle until groundwater fills the pit and lifts a float, then it runs at full power until the pit is empty, then it stops.
So there are two numbers that matter:
- How hard it pulls while running. A typical one-third horsepower pump draws roughly 600 to 1,000W. Check the label on yours. A half horsepower pump is nearer the top of that range.
- How much of each hour it runs. This is the number the weather sets. A dry week might mean a pump that runs for two minutes an hour. A hard storm on saturated ground can mean twenty minutes an hour or more.
A pump also needs a brief burst of extra power to start, often two to three times its running watts for a second or less. Even at the top of that range a typical pump is well under the 3,600W a HomePower 3000 puts out, so starting the pump is not the problem. Battery life is.
How long it runs, by weather
These figures assume an 800W pump and count the battery alone, with no solar. They ignore conversion losses, so real runtimes will be roughly 10 to 15 percent shorter.
| Weather | Pump runs | Average draw | Energy a day | HomePower 3000 (3,072Wh) | HomePower 3600 Plus (3,584Wh) | 5000 Plus (5,040Wh) |
|---|---|---|---|---|---|---|
| Light seepage | 2 min an hour | about 27W | about 640Wh | about 4.8 days | about 5.6 days | about 7.9 days |
| Steady rain | 6 min an hour | about 80W | about 1,920Wh | about 1.6 days | about 1.9 days | about 2.6 days |
| Severe storm | 20 min an hour | about 267W | about 6,400Wh | about 11 hours | about 13 hours | about 19 hours |
Two things stand out. In ordinary rain the HomePower 3000 comfortably outlasts a normal outage. In a severe storm on saturated ground, every unit runs down within a day, and that is when the grid is most likely to be down for longest.
Check the current price of the HomePower 3000 at Jackery (panels included)
Finding your own run time
You do not need to guess. Watch your pump through a rainy afternoon and time it.
- Read the label on the pump for its running watts. If it lists amps instead, multiply amps by 120 to get watts.
- Time one cycle. Note how many seconds the pump runs each time it kicks on.
- Count cycles in an hour during the heaviest rain you have seen this year.
- Do the sum. Running watts times minutes running per hour, divided by 60, gives your average draw in watts. Multiply by 24 for a day’s energy in watt-hours.
Take the result and divide your battery’s capacity by it. That is your runtime. Our guide to sizing a solar generator covers the same method for the rest of your loads, and it is worth doing before you buy because a sump pump is rarely the only thing you want to keep running.
Solar recharge over a multi-day storm
This is where panels earn their place, but be realistic about when they help.
Sump pumps matter most during heavy rain, and heavy rain means thick cloud. A solar panel under a heavy overcast returns only a fraction of its rating. The tidy answer is that panels will not carry a pump through a severe storm, and the battery has to.
Where they do matter is the days around it. Light seepage barely dents the battery, so a few hours of sun between showers refills what the pump used. And after a storm clears, a bright day returns 1,500 to 2,000Wh, enough to put back most of a day of steady rain and have the unit ready for the next one. Our guide to how many panels charge a HomePower 3000 shows the charge-time sums.
Plugging in safely
A sump pit is a wet place, and the combination of water and mains power deserves care.
- Keep the unit dry and high. Put it on a shelf, a bench or the stairs, never on the basement floor. If the room floods, the battery must be well above the water.
- Run the cord, not the unit, to the pit. Use a heavy-duty outdoor-rated extension cord sized for the pump’s amps, as short as possible, and keep the plug connections off the floor.
- Never run a gas generator in a basement. Carbon monoxide builds up fast in a closed space, and it kills people in almost every major outage. A battery unit produces no exhaust, which is the main reason it suits this job.
- If the pump is hard-wired, do not improvise. Hard-wired pumps and transfer switches are electrician work.
If you are unsure about any of this, ask an electrician. It costs far less than a flooded basement or an injury.
What else the unit can run beside the pump
A pump that runs for minutes an hour leaves most of the battery free, which is the useful point about this load. On a HomePower 3000, a day of steady rain costs the pump about 1,920Wh, which leaves roughly 1,100Wh for:
- Wi-Fi and a phone charger, around 250 to 400Wh a day, so you can follow the weather and the power company’s updates.
- A few LED lights, around 300Wh for a long evening.
- A fridge, at 1,000 to 1,500Wh a day, which is tight alongside a busy pump. Our fridge runtime guide works it through.
If you want the pump plus the fridge plus the essentials for several days of storm, the sensible step up is the 5000 Plus or an expandable setup. The home backup buying guide lays out each unit against the same list.
Battery generator or backup pump?
A solar generator is not the only way to keep a basement dry in an outage, and it is fair to compare.
A battery-backup sump pump is a second, smaller pump with its own battery that sits in the pit and takes over when power fails. It does exactly one job and does it automatically, without you being home. Its weakness is size: the batteries are small, and the backup pump moves less water, so it can run out in a long storm.
A solar generator powers your existing pump, which is already sized for your pit, and the same unit also runs your fridge, lights and phones afterward. The trade-off is that someone has to plug the pump in. If nobody is home during storms, a backup pump or a plug-in routine you rehearse in advance matters more than which battery you choose.
Many households sensibly do both: a small backup pump for the hour you are out, and a solar generator for everything else.
Which unit to buy
For most basements, the HomePower 3000 is the right size. It outlasts steady rain by a comfortable margin, handles the starting surge, runs silently with no exhaust, and includes panels to refill between storms.
Step up to the 3600 Plus or the 5000 Plus if your pit fills often, if you have a larger pump, or if you want the pump and a fridge running together through a multi-day event. If you live somewhere with a high water table, size for the severe storm row of the table rather than the steady rain row.
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Keep reading: Best solar generators for home backup · How to size a solar generator for home backup · Solar generator vs gas generator · Can a solar generator power a whole house?