For most homes we would pick the Zoeller Aquanot Spin 508, a 12 V battery backup that tests itself and whose flow figures were measured on a real battery. The Liberty 442-10A StormCell matches its flow with a clearer wall display. If your pit is narrow, the Basement Watchdog CITE-33 combo fits it, and if you are on city water and lose power for days, the water-powered Basepump HB1000-PRO needs no battery at all.
A backup sump pump sits in the pit beside your main pump and takes over when the power goes out, the main pump fails or water comes in faster than it can cope. What separates a good backup from a weak one is how much water it moves at a real lift, how long it runs on one battery, and whether it tells you, without Wi-Fi, that something is wrong. Compare every model in our backup sump pump comparison.
A backup pump is one of five ways to protect a basement; the flooding page covers the others, from leak sensors to a backwater valve.
All four picks are backups, not main pumps: each one expects a working primary pump in the same pit, except the CITE-33, which brings its own. We ranked them on the makers’ published figures, read from their spec sheets and manuals, and on how much looking after each one needs.
How we ranked them
- Backup flow at 10 ft Gallons an hour at a typical basement lift, not at zero lift.
- Run time Hours of continuous pumping on one battery, or what limits a water-powered unit.
- Alarms that work offline A local alarm that sounds with no internet.
- Fit and upkeep Pit size, battery care, testing and warranty.
Our picks at a glance
-
Best battery backup
Zoeller Aquanot Spin 508 12 V Battery Backup Sump Pump System
Self-testing 12 V backup rated on a real battery
- 1,800 gal/h backup at 10 ft
- 5.5 h continuous
- 3-yr warranty
CA$761.67at Amazon.caPrice checked . Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.ca at the time of purchase will apply to the purchase of this product.Check price at Amazon.ca (opens in a new tab)Canadian retailersCA$761.67at Amazon.caPrice checked . Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.ca at the time of purchase will apply to the purchase of this product.Check price at Amazon.ca (opens in a new tab) -
Best backup display
Liberty Pumps 442-10A StormCell 12 V Battery Backup Sump Pump
Pro-grade 12 V backup with LCD panel and redundant float
- 1,800 gal/h backup at 10 ft
- 5.5 h continuous
- 3-yr warranty
-
Best combo system
Basement Watchdog Combo CITE-33 Primary and Battery Backup Sump Pump System
Primary and backup preassembled; fits a 10 in pit
- 1,000 gal/h backup at 10 ft
- 2-yr warranty
- 22 ft max lift
CA$572.76at Amazon.caPrice checked . Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.ca at the time of purchase will apply to the purchase of this product.Check price at Amazon.ca (opens in a new tab)$379at Amazon.comPrice checked . Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.Check price at Amazon.com (opens in a new tab) -
Best without a battery
Basepump HB1000-PRO Water-Powered Backup Sump Pump
No battery: runs on city water pressure for as long as it lasts
- 1,000 gal/h backup at 10 ft
- Works in an outage
- Float-operated water valve switch
Side by side
| Specification |
 Best battery backup Zoeller Aquanot Spin 508 12 V Battery Backup Sump Pump System
CA$761.67
|
Best backup display Liberty Pumps 442-10A StormCell 12 V Battery Backup Sump Pump |
 Best combo system Basement Watchdog Combo CITE-33 Primary and Battery Backup Sump Pump System
CA$572.76$379
|
Best without a battery Basepump HB1000-PRO Water-Powered Backup Sump Pump |
|---|---|---|---|---|
| Our score | Our score: 8.2/10 out of 10(best in this row) | Our score: 8.0/10 out of 10 | Our score: 7.6/10 out of 10 | Our score: 7.9/10 out of 10 |
| Backup flow at 10 ft | 1,800 gal/h | 1,800 gal/h | 1,000 gal/h | 1,000 gal/h |
| Continuous run on battery | 5.5 h | 5.5 h | not listed | not listed |
| Maximum lift | 22 ft | 21.5 ft | 22 ft | not listed |
| Minimum pit width | 16 in | not listed | 10 in | 10 in |
| Battery | 12 V deep-cycle, Group 27, 29 or 31 (not included) | 12 V lead-acid deep-cycle, Group 27 or 31 (not included) | 12 V AGM, BW-27AGM recommended (not included) | not listed |
| Water pressure needed | not listed | not listed | not listed | 40 psi |
| Phone alerts | No | No | No | No |
| Warranty | 3 years | 3 years | 2 years | 5 years(best in this row) |
| Where to buy |
Canadian retailers |
Two things the table can’t show. First, the three battery systems are all sold without a battery, so budget for one. Second, the flow figures are the makers’ own: Zoeller and Liberty both state theirs on a 12 V battery, which is how a backup actually runs in an outage.
Best battery backup
1. Zoeller Aquanot Spin 508
- Backup flow at 10 ft
- 1,800 gal/h
- Works in an outage
- Yes
- Continuous run on battery
- 5.5 h
- Switch
- Vertical float
- Minimum pit width
- 16 in
- Phone alerts
- No
The Aquanot Spin 508 earns the top spot because it watches itself. Its controller charges the battery in stages, runs the pump on a schedule and sounds an alarm for pump, float, battery and power faults, so a dead battery is found on an ordinary Tuesday rather than in a storm. Zoeller’s sheet gives 30 gallons a minute at 10 ft on a 12 V deep-cycle battery, and about 5.5 hours of continuous pumping on a 175-minute battery; pumping on and off, as most pits do, lasts much longer. The catch is space: Zoeller asks for a pit at least 16 in across and 22 in deep, so it won’t fit the narrowest pits. There is no Wi-Fi on this version; Zoeller’s Fit 508 adds it. Zoeller also says the wiring and controls should be fitted by a licensed electrician.
Pros
- 30 GPM at 10 ft, measured on a 12 V deep-cycle battery
- Tests the pump on a schedule; alarms for pump, float, battery and power faults
- About 5.5 hours of continuous pumping on a 175-minute battery
Cons
- Battery sold separately
- Needs a pit at least 16 in across and 22 in deep
Where to buy
CA$761.67at Amazon.ca Price checked . Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.ca at the time of purchase will apply to the purchase of this product.
Check price at Amazon.ca (opens in a new tab)Canadian retailers
CA$761.67at Amazon.ca Price checked . Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.ca at the time of purchase will apply to the purchase of this product.
Check price at Amazon.ca (opens in a new tab)Best backup display
2. Liberty Pumps 442-10A StormCell
- Backup flow at 10 ft
- 1,800 gal/h
- Works in an outage
- Yes
- Continuous run on battery
- 5.5 h
- Switch
- Pipe-mounted float switch
- Phone alerts
- No
- Warranty
- 3 years
The Liberty 442-10A matches the Aquanot’s flow, 30 gallons a minute at 10 ft on a battery and 35 with mains power on, and Liberty gives the clearest run-time figures we found: about 5.5 hours of continuous pumping on a Group 31 wet battery, or roughly eight days if the pit cycles four times an hour. A high-water float doubles as a second on switch, and the wall panel has an alarm, a test button and its own 9 V standby battery, which Liberty says to replace at least once a year. It doesn’t test itself on a schedule, so the test button is your job. Liberty’s manual asks for the backup’s own fused circuit, apart from the main pump’s, and for CO alarms to sit at least 15 ft from the battery and charger to avoid false alarms. The 442-10A-EYE version adds phone alerts.
Pros
- 30 GPM at 10 ft on a 12.1 V battery (35 GPM with AC power on)
- About 5.5 hours continuous at 10 ft on a StormCell Group 31 battery
- High-water float sounds the alarm and acts as a second on switch
Cons
- Battery sold separately
- No phone alerts on the standard 442-10A (the -EYE version adds them)
Best combo system
3. Basement Watchdog Combo CITE-33
- Backup flow at 10 ft
- 1,000 gal/h
- Works in an outage
- Yes
- Switch
- Dual float switch
- Phone alerts
- No
- Motor
- 0.33 HP
- Flow at 10 ft
- 3,100 gal/h
The CITE-33 is the one to look at when the main pump is due for replacement anyway, or the pit is too narrow for a second pump. It comes as a single plumbed assembly: a cast-iron 1/3 HP main pump, a 12 V backup, check valves and dual floats on both, and it drops into a pit as small as 10 in wide and 14 in deep. The trade-off is the backup itself: 1,000 gallons an hour at 10 ft, little more than half of the two pumps above. When its battery alarm sounds in an outage, the manual says about half an hour of pumping is left. Basement Watchdog publishes a Canadian manual, and lists CSA on the main pump and cUL on the float and controller. The base warranty is two years, with extra years for the maker’s battery and for registering online.
Pros
- Primary and backup come plumbed together, check valves fitted
- Fits a sump pit as small as 10 in wide and 14 in deep
- Primary moves 3,100 GPH at 10 ft; cast-iron AC pump
Cons
- Backup pump moves only 1,000 GPH at 10 ft, 15 ft maximum head
- 2-year base warranty (a year more each for its battery and registration)
Where to buy
CA$572.76at Amazon.ca Price checked . Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.ca at the time of purchase will apply to the purchase of this product.
Check price at Amazon.ca (opens in a new tab)$379at Amazon.com Price checked . Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.
Check price at Amazon.com (opens in a new tab)Best without a battery
4. Basepump HB1000-PRO
- Backup flow at 10 ft
- 1,000 gal/h
- Works in an outage
- Yes
- Water pressure needed
- 40 psi
- Switch
- Float-operated water valve
- Minimum pit width
- 10 in
- Phone alerts
- No
The Basepump HB1000-PRO has no battery and no motor. City water pressure drives an ejector that lifts sump water out, so it keeps going through an outage of any length, as long as the water supply holds. Basepump’s table gives about 950 gallons an hour at 10 ft with 40 psi and 1,000 at 60 psi. That comes at a price: it needs at least 40 psi and a 3/4 in service, it uses about a gallon of city water for every 1.5 to 2 gallons it removes, and it isn’t for private wells. Basepump also says most plumbing authorities require an approved backflow preventer; the kit includes a dual check valve, but your town may ask for a different device. Read our battery vs water-powered comparison before choosing this route.
Pros
- No battery or charger to maintain; runs as long as water pressure lasts
- About 1,000 GPH from the sump at 60 psi and 10 ft lift
- Brass dual check valve, shut-off valve and push-fit fittings included
Cons
- Needs city water at 40 psi or more and a 3/4 in service: not for wells
- Uses about 1 gallon of city water for every 1.5 to 2 gallons pumped
Where to buy
US retailers
Basepump (Base Products Corp.)Price on the retailer’s site
Check price at Basepump (Base Products Corp.) (opens in a new tab)Basepump (Base Products Corp.)Price on the retailer’s site
Check price at Basepump (Base Products Corp.) (opens in a new tab)How to choose a backup sump pump
Start with the reason you need one. If the worry is power cuts, any of these will do. If the worry is a main pump that wears out, remember why most of them do: owners of the Zoeller M53 we read say its built-in float switch is the usual part to go after some years, so a backup with its own float covers exactly that failure. If water comes in faster than your main pump can clear it, no battery backup will keep up for long, and a bigger main pump such as the Zoeller M98 may help more. See every main sump pump we track.
- Check the flow at 10 ft. A backup moves less water than a main pump. Compare figures at your lift, not the maximum at zero lift.
- Measure the pit. The Aquanot needs 16 in across; the CITE-33 and Basepump fit a 10 in sump.
- Pick the right battery. Use the deep-cycle type the maker names; a car battery is a stopgap only (see the questions below).
- Give it a separate way out. Basepump recommends its own outdoor discharge, so a frozen or blocked main line can’t stop both pumps (the CITE-33 shares one line by design, with check valves on each pump). Liberty asks for a separate circuit, so a tripped breaker on the main pump doesn’t stop the charger.
- Get an alarm you’ll hear. All four have a local alarm. A Wi-Fi alert can’t reach you when the router has lost power; a separate battery water alarm on the floor is a cheap second warning. Compare water alarms and leak sensors.
What the money goes on
- Battery backup added to your pump: the backup unit plus a deep-cycle battery bought separately, and a battery to replace every few years.
- Combo system: a new main pump and backup in one box, plus the battery. Worth it when the old pump is due for replacement anyway.
- Water-powered backup: no battery to buy, but plumbing work, possibly a code-required backflow preventer with its own testing, and the city water it uses each time it runs.
A backup pump keeps groundwater out. It does nothing about sewage coming up a floor drain from the city sewer: that is a backwater valve’s job, and some cities require or subsidise them (our backwater valve guide shows how one region’s rules and grants work). If the basement is already wet, start with what to do first when a basement floods.
How we chose these
- Started from what decides a backup pump: flow at 10 ft, run time per battery, pit size and an alarm that works offline.
- Read the makers’ spec sheets, manuals and FAQ pages for each model, and compared their published figures side by side.
- Checked prices at the retailers we could read and show the date we checked. We haven’t yet found a Canadian seller with a readable price for these four.
- Revisit the list when a model, a battery or a code rule changes.
What we don’t do: lab-test or install these pumps. We haven’t yet read enough owner reviews that name these exact models to summarise them.
Backup sump pump questions
Do I need a backup sump pump?
If your basement relies on a sump pump and you lose power in storms, yes, it is the usual answer. A backup also covers the main pump’s own failures, such as a stuck float. It won’t stop sewer backup through floor drains; that needs a backwater valve.
How long does a battery backup sump pump run?
Running non-stop, about 5.5 hours on a full deep-cycle battery for the Zoeller Aquanot Spin 508 and Liberty 442-10A, by their makers’ figures. Most pits don’t run non-stop: Liberty puts its run at about eight days if the pump cycles four times an hour. Heavy inflow drains the battery far faster.
Can I use a car battery?
Only as a stopgap. Liberty and Basement Watchdog both say a charged car battery can keep the backup running in a long outage, but each names a deep-cycle battery for everyday use: Group 27 or 31 for the Liberty and Zoeller, the BW-27AGM for the CITE-33. Swap the deep-cycle battery back once the power returns.
How often should I test a backup sump pump?
Follow the maker. The Aquanot tests itself on a schedule and has a test button. Liberty’s panel has a test button and needs a new 9 V battery at least yearly. Basement Watchdog says to maintain the CITE-33 once or twice a year, and Basepump suggests a test every two to three months.
