Questions - Battery Back-up Sump Pump

[Keith]

Hi

I have a sump pump in a well beneath my floor. Works great and keeps the basement dry. However I fear that we may get water at the same time we have a power outage. So I've been looking at battery back-up units. Most kits that I've found in stores around here have a 12 volt pump that attaches to the outlet of the existing electric pump. It kicks in if the water rises in the well above the cut-in level of the AC float. This DC pump is powered by a deep-cycle battery (not included) that is kept charged by trickle charger (included).

The kits include the 12 volt pump, a charger, a plastic box to hold the battery, and a few fittings. The cost here in Canada is between $250 and $380 (I think the more expensive ones have a fancier charging unit and perhaps the pump delivers more gallons per minute. Isn't that a bit expensive for what you get? Especially as there is no battery included?

I'm wondering if I could purchase the pump and a trickle charger separately for considerably less. Someone suggested a marine bilge pump. Do these pump the volume of the sump pumps - about 20-25 gpm? Is the trickle charger sold in the kits any different/better than a cheap trickle charger sold at any hardware/automotive store? The ones in the kit don't look to be all that elaborate. Also, are all deep-cycle batteries equal? If they are left on charge continually, will they hold a full charge for a long time (years)? How often would they have to be replaced?

Any suggestions or assistance would be appreciated.

Keith

[hallerb]

batery will need replaced every 2 to 3 years no matter what you do. by

4 years the batterys capacity will be small., that is run time will get shorter and shorter.

there are also water powered back up sump pumps if your on city water.....

[hallerb]

batery will need replaced every 2 to 3 years no matter what you do. by

4 years the batterys capacity will be small., that is run time will get shorter and shorter.

there are also water powered back up sump pumps if your on city water.....

[Bob]

I saw one of those advertised a long time ago. Do you know how good they work?

[Don Allen]

Keith,

I've gone through two battery-back up systems using battery-powered DC motors in this house since 1990. I've really never been happy with their performance, and the deep-cycle marine batteries never seem to last as long as they should.

Although I know the initial inductive kick of the typical AC sump pump pulls quite a bit of current, it seems to me the best alternative would be analagous to a computer UPS. Simply plug the normal sump pump into the UPS-like device, and once there's a AC power outage, the device's inverter takes over and feeds the pump with 115VAC.

Personally, I've always thought such a device would be a big seller throughout the country, but I've never seen such a product. Most likely, it's due to the overall cost because of the initial turn-on current requirement, as well as the continuous current use, of most sump pumps.

Nevertheless, I still think it's a viable idea, and if someone could come up with an effective design and manufacture it in China, perhaps it could be brought to market for a reasonable price.

[Toller]

Do you know how big the UPS would have to be to start a sump pump? Besides, what is your back up if the pump simply breaks? Rotten idea.

[Toller]

If the components are cheaper, and the pump has adequate capacity (I don't picture bilge pumps handling a 10' head, but then I don't know much about bilge pumps...) then it ought to work. All you would lose would be the buzzer and lights that tell you what is going on.

[trader4]

"batery will need replaced every 2 to 3 years no matter what you do. by

4 years the batterys capacity will be small., that is run time will get

shorter and shorter. "

And why is that? Even a car battery lasts 5-7 years. Lead/acid batteries will last a long time if kept properly charged. The killer is the number of times they are discharged. Even worse is to discharge them and leave them that way for an extended period. If used for emergency stanby, a battery will last a very long time. Just ask the phone company. They have huge banks sitting there to power the phone system during a power failure.

[calhoun]

Battery backups have a limited run time before the battery dies. I don't see the point. For the price, you mentioned, you can buy a small genset and run an extension cord. As mentioned before, if you have city water, a water operated backup works fine.

[Keith]

Unfortunately I'm on a well so loose my water pressure when power is cut to the pump.

Keith

[Keith]

From full charge to discharge would the pump immediately begin to slow down (less gpm) or would it maintain its full capacity to pump until the battery power got to a certain level? What I mean is, if the battery was 1/2 discharged, would the pump only pump 1/2 the volume of water?

Sorry of these seem like pretty basic questions, unfortunately electricity is not one of my strong points.

Keith

[Keith]

I thought about a UPS but in searching on the 'net the consensus is that no reasonably-priced UPS could handle it. The pump would draw too much and the UPS would be discharged in minutes. From what I've been able to find on line, any UPS able to sustain the power draw for a reasonable period of time would cost thousands of $$$. Apparently 12 Volt pumps are much more efficient. The other advantage is that it would be a backup not only for a power outage but in the case of the main pump failure as well.

Thanks for replying.

Keith

[m Ransley]

or have city water powered backups that outperform even some AC pumps. Battery are a joke, research how much and for how long they pump on a new and old battery and the cost of charging and battery replacement. Best is a gen or a gasoline powered pump if you have a well and flood

[Keith]

I have a old 1750 watt generator. My concern is that we would loose power (a rarity here but still about once per year for a few hours on average)or the main pump failed in the middle of the night or while we were away from the house. If it happened that the sump was getting water at the time, the sump would overflow, probably causing major problems under the sub floor in my basement. I'm hoping a battery-powered system would be able to take over until I would be able to get the generator hooked up. They advertise these systems can empty the average sump well about 1000 times on a single charge at about 20-25 gmp. That should be plenty enough to give me time to make other arrangements.

I just thought that the cost at around $300 CDN or more seemed excessive for what you get - a 12 volt pump, a charger, a plastic box (for the battery) and a few connections. Are 12 volt pumps really that expensive? I just thought maybe I could save a bit by buying the components separately. Maybe not. Around here I can only find these pumps sold in kits.

Thanks for taking the time to reply.

Keith

[hallerb]

You car batterys capacity when its brand new is oversized for its job, so you cant see its decreasing capacity. but decrease it does slowly frm the day its manufactured.

battery backups for phone companies used HUGE BANKS of very low capacity but long lived batteries. with solid lead plates holding rosettes, would up thin solid lead. I have seen those batteries. last

30 years or more, but a big group would of been needed to start your car. because heir capacity is so low...

mow take some marine batteries put them on a UPS. 12 volts in 120 out. sounds great. but check the UPS manufacturers, the batteries used in these last for just a few years at most. The UPS I use on my tv satellite system is not quite 3 years old, run everything for a hour and a half when new, now perhaps 20 minutes... battery is worn out.. costs nearly as much as a like sized brand new UPS:( I might add there are tons of FREE UPS available nationwwide, all with bad batteries...

converting the 12 volts to 120 to run whatever isnt efficent, you lose over 20% in the conversion process, transistor losses etc.

The BEST choice but pricey is a standby generator system. these monitor the power line and any time theres a minute outage, the generator starts, and switches over important loads in the home, sump pump, fridge, furnace, etc and some lights. they use natural gas or propane for fuel. easily cost 5 grand and up, I would like one some day.

the next best choice is a stand alone generator, 300 bucks and up, to ru run one critical load at a time. I have 2 of these, a few thousand watts, for real emergencies.

noisey, need gasoline, its not perfect but thy work. in this choice you must be home to run it.

of course the best sump pump choice is fuel free. if your sump happens to be higher than a low spot on your property, install a underground pipe as a overflow. its always there and requires no real work after the initial install.

[Keith]

Ref my other posts. I'm not on city water so a power outage would knock out my well pump and therefore the water pressure needed to power the auxilliary pump. I have a generator but how would I know there is a problem before I can hook it up. What if I'm sleeping or away when the power goes out or if the main pump gives up the ghost? I need something to fill the gap until I get my generator running.

Keith

[Marc_G]

These are no longer allowed in many places. My city allows them but the next one over does not. The concern is that it is possible (albeit unlikely) that the water from the sump could mix with, and contaminate, the house water supply. Clearly the systems are designed to prevent this but according to my plumber, there are documented cases of hardware failures leading to this situation.

If you need a battery backup, invest in a good one, and replace the battery every two years. Cheap insurance.

Marc

[hallerb]

the 300 bucks is a bargain for a 12 volt pump system but remember every few years you will need a new battery, or find your pump time shrinks from hours to minutes. it will pump about the same volume to battery exhaustion.

when looking at pump capacity look at head, how high it has to pump. if you go this way dont feed the backup pump to the same drain line as the primary pump.

if the primary pumps check valve fails, you will folld anyway.

incidently a short term flood of the underside of your basement floor isnt a disaster. its when the water floods your basement and ruins your stuff that matters

[George J]

I recently talked to someone that has city water, and it quits during a power failure.

[Mark]

if the amount of water you get can be handled by a smaller pump like the general pourpose pump sold at harbor freight that pulls about 200 Watts, a 750 Watt inverter will START and run these pumps. Yes the pull during start is a lot higher than at run and you need an inverter that can work through the start. I keep a car battery on a trickle charger , and a 750 Watt inverter and one of these pumps around for emergencies... or you can connect the inverter to your car ,,,, and have a small generator for longer term outages...

Yes I would have to be here, it is not automatic...

Mark