Battery or water backup for sump

Old 02-27-18, 08:02 AM
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Battery or water backup for sump


Have a water backup on our sump pump. Just moved here. Are battery backups a better alternative?

Iím worried about k aging the water main on when we go on vacation but I have no choice in case the power goes out and I need the sump backup.

Why would someone choose the water backup vs battery?
Old 02-27-18, 09:32 AM
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Water backup doesn't require batteries and a charger. You also have to replace the batteries when they get old. You also have to consider how long the battery will last. If the battery dies before the power comes back on the pump stops and you have flooding.

Water powered pumps are not perfect either. They waste a lot of water to pump out water so if it's run for a long time you will definetely notice it on your water bill. It requires a supply of pressurized water. If there is a problem with your municipal water supply your pump looses it's power source.

With either system you need to make sure it's appropriately sized. I've seen people with a electric pump that moves 1'000 gallons per hour and barely keeps up during rains but then they install a 500 gallon per hour backup. So, if the power goes out during heavy rains even when it's working the backup can't keep up with the inflow.
Old 02-27-18, 10:21 AM
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I went a slightly different route, being on a well a water pump was not an option. My basement already had 2 sump pits interconnected so if one pump failed or was overwhelmed the water would flow to the other pit. We also sized each pump to handle the max calculated flow of both pits together. I then installed a 24 volt inverter / charger connected to a bank of 4 6 volt golf cart batteries, this is hardwired to 2 separate 15 amp dedicated circuits (1 per pump) providing power.

When I 1st installed this we also had a portable generator I could connect if home or for prolonged outages. I have tested this a few time and get approximately 24 of run time on the system during a heavy storm. it can go days under normal usage more than enough time for me to get home or call a friend.

We have since put a whole house generator in to run the well, grinder pumps , fridge lights ect...

I left the system in place for that one time the generator does not start

Old 03-10-18, 03:22 PM
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wtr power'd backup pumps use 1gal for every 2gal they pump out,,, seems like a reasonable cost compared to a battery dying from overwork OR the std under-size 12v pump & resultant cost of damage from same,,, you don't have this option if on a well of course
Old 03-11-18, 07:36 AM
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I have to agree with PD on this. No backup system is 100% reliable. My son tried just about every type there is and they all failed one time or another. He ended up with a whole house generator and a second pump set at a higher level to switch on in the event of the primary pump failure.

My daughter went the way of Paul and used two industrial type sumps in two pits. She also was on a well system.

If you're going to be away for extended periods of time I suggest a two prong strategy. One, get a camera focused on the pit and a internet via the phone app. That way you can check in on the pump periodically. Two, have a friend or relative check on the situation if a storm, heavy rain or power outage occurs. Give them specific instruction on how to proceed if pump fails or power goes out.

Also most insurance companies offer flood damage in basement for major appliances at a nominal cost (also about a $1000 delectable).
Old 03-15-18, 07:24 PM
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aubinp is on the right track. ditch the water pump it will not have the capacity to keep your basement dry. same goes for the "12V battery backup systems" aka "basement watchdog"... the ones with 12V pumps. they are all junk. you need 120VAC pumps. 2 of them. Storm Pro BA33M is a good choice. power at least one with a DC-AC power inverter (12V or 24Vdc to 120VAC). Note this is not the same as "battery backup pumps"... it's main pumps powered by inverters that convert battery power to 120VAC.

you can get all-in-one inverter/charger/auto transfer switch. this is the easiest to hook up, but expensive. it's cheaper and more reliable to use separate components, but the set up is more complex.

I prefer marine deep cycle batteries to golf cart battries. I tried GC batteries and they died after a few years not sure why. my bank of marine deep cycles is going on 8 years and still running strong. as aubinp says such a set up will run a 1/3hp pump for days under intermittent duty cycle.

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