Could you help with ideas for a battery backup for sump pump.

[AC\DC]

Client has a sump pump and he has had he house flood when the power goes out.
He was told by another ec to go with a hole house generator.
I was wondering if there is a nice battery backup with automatic transfer for single loads.
He only wants the 3/4 jp 120volt motor on some form of a backup. And he won’t be home since it’s a vacation home.
Pump needs to run once a day for 5 days. About 3 hours
Any ideas!
I have no experience with battery backup system.

 

[infinity]

From personal experience I can say that battery backup systems for sump pumps are a poor choice but once a day for 5 days it might be okay. If there is not a well I would use a water driven backup pump.

 

[James L]

This would run about $800 including a deep cycle battery...

2000W Primary Sump Pump Backup Power System

<ul> <li>Automatically switches over to battery power when AC power goes out. A PumpSpy Deep Cycle AGM Battery (not included) is recommended</li> <li>Generates a Pure Sine Wave 120 VAC voltage to reliably power your primary sump pump</li> <li>Automatically recharges a battery When AC Power...

shop.pumpspy.com

 

[AC\DC]

I think he pulling water off the lake.
I’ll ask him a google “ water driven backup pump”
Those are really cool.

 

[James L]

From personal experience I can say that battery backup systems for sump pumps are a poor choice but once a day for 5 days it might be okay. If there is not a well I would use a water driven backup pump.

Are you talking about a backup for 120v pump or 12v backup pump system? I'm curious what kind of issues you've had

 

[tom baker]

I would recommend a 12 or 24 vdc pump. This avoids the expense of an inverter and the conversion losses from dc to ac

 

[AC\DC]

I would recommend a 12 or 24 vdc pump. This avoids the expense of an inverter and the conversion losses from dc to ac

I’ll look into that also. Hoping he on city water lol.

 

[infinity]

Are you talking about a backup for 120v pump or 12v backup pump system? I'm curious what kind of issues you've had

I had a 120 volt pump with an inverter but when we lost power after a tropical storm for 7 days the battery wouldn't last 24 hours. I had to use an extra battery out of my boat and charge it at my inlaws house who had power swapping them out. If I wasn't around the basement would have flooded.

 

[Todd0x1]

Rough math shows you need about 10kwh of battery to get your 3 hours a day * 5 days of runtime. About $3500 for enough batteries (lead/acid) and an appropriate inverter/charger. About $8k to do it with lithium. Inverters don't like motor loads so you want to substantially oversize it. Does the pump start against alot of head pressure? Might want to get a reading of its starting amps.

 

[infinity]

About $8k to do it with lithium.

Ouch.

 

[gadfly56]

Rough math shows you need about 10kwh of battery to get your 3 hours a day * 5 days of runtime. About $3500 for enough batteries (lead/acid) and an appropriate inverter/charger. About $8k to do it with lithium. Inverters don't like motor loads so you want to substantially oversize it. Does the pump start against alot of head pressure? Might want to get a reading of its starting amps.

At those prices, a small generator is looking like a good option. Since sump pumps are very intermittent loads, a generator/charger/battery arrangement might be cost effective. It would be much more attractive if there are other loads the customer wants to carry as well.

 

[ptonsparky]

Utility, Generator, battery plus a cell enabled alarm system when the first three all fail. Or maybe before they all fail.

How deep is their pocket book?

 

[AC\DC]

He got deep pockets I going to look into the 24 volt pump option

 

[Todd0x1]

He got deep pockets I going to look into the 24 volt pump option

Still going to need $$$$ in batteries, and charger. I would be curious to see the cost comparison between 24v pump and suitable battery charger vs inverter/charger and use existing pump. I was budgeting based on $1500 for a 2200w ETL listed pure sinewave inverter/charger which also has built in transfer switch.

 

[synchro]

If you include a generator in addition to a battery backup pump, I think some thought should be done about when the generator should run. If a sump pump is the only thing needing backup, then clearly the generator should not run all the time that the power is out. Maybe the generator could be activated with a float sensor in the sump or when the battery powered sump first runs. And then the generator could time out, perhaps some hours later. Many control options could be considered depending on the situation.

 

[Todd0x1]

If you include a generator in addition to a battery backup pump, I think some thought should be done about when the generator should run. If a sump pump is the only thing needing backup, then clearly the generator should not run all the time that the power is out. Maybe the generator could be activated with a float sensor in the sump or when the battery powered sump first runs. And then the generator could time out, perhaps some hours later. Many control options could be considered depending on the situation.

There are some inverter/chargers with a generator input and generator start function

 

[Todd0x1]

There are some inverter/chargers with a generator input and generator start function

Oh. The inverter/charger I had in mind for this actually has a 2nd AC input for generator and a programmable relay output that can be used to start the generator https://samlexamerica.com/products/2200-watt-pure-sine-inverter-charger-evo-2224/#