I am looking for a little help in designing my own battery backup sump
pump. I know that they sell kits that have everything that you need,
but the pumps they use must be mounted in the sump hole. My sump hole
is small so the backup pump must be mounted on top of the existing
pump. This means that the sump must be almost completly full of water
before the backup has enough water to start to pump. I don't like this
so I would like to create my own system. My basic idea is to use a deep
well battery along with a dc style pump. But I want the pump to stay
out of the sump and just a pipe going into the sump. This way I can put
the pipe down at the same level as my current pump. I'll still need
some sort of float to start it and some way to recharge the battery
when it gets low. These are the things I don't know how/what to use.
Does anyone have suggestions?
Two separate questions:
1) Do you have propane, or natural gas available?
2) In the sump hole, near the surface, could you fit an object a little
smaller than a sheet of notebook paper? If yes, you might consider using a
marine bilge pump. Here's one that looks like its footprint is about 5" in
diameter. 1800 gallons per hour. If you've got more water to move, you've
got other problems. :-)
OK...talking out of my axx here, but couldn't you put a relay in
between the battery and the emergency pump such that power would only
be applied to the emergency pump when the AC was lost?
You can get relays that can be set up to be "always open" when AC is
applied to the input. When the AC is lost, the output contacts from the
battery will close and power will be available to the emergency pump
I'm thinking you could hook up the original float mechanism such that
it powered on both pumps at the same time, but only the one with power
would actually come on.
It's not BS if your sump doesn't have running water anywhere in the
vicinity, or if the sump is active enough during a downpour to overrun
the piss poor flow rate of the water powered pump. There are a LOT of
sumps out there that will flood with a water-powered pumping toy.
Personally, the only time I care about the sump pump and power going
out is during heavy downpours when not coincidentally, there is a
maximum of water coming into the drainage tile. Even Zoeller
themselves downplays this pump as "The ideal economical standby to an
electric sump pump."
Granted though, it will run forever, unlike a battery pump which is
limited to battery capacity on hand.
But with a 10' height, Zoeller's water powered toy delivers--at
best--a scant 239-479 gallons/hour depending on your water pressure.
And even those numbers come with the fine print of "Pump capacity
varies due to: Inlet Water Pressure, Working Water Pressure, Discharge
Elevation, Number of Pipe Fittings, Inlet and Outlet Hose Size, Fluid
Viscosity, Degree of Water Clarity, Water Temperature, Cleanliness of
Intake Screen. The flow rates in the chart are approximate values."
Are you down there cleaning your inlet screen regularly? Ever?
Basement Watchdog battery operated backuppumps, 1000GPH for the
cheapest model, 1730 for the Special and 2200GPH for their Big Dog.
Zoeller also sells the Basement Sentry battery backed systems of
similar flow rates, probably most comparable to the Big Dog:
So neither option is unqualified BS. If your pump doesn't run much
when it rains, you don't have a lot of rise to overcome, and you have
strong water pressure and a supply near your sump, the water-powered
pump might be a good fit for you. In all other cases, the
water-powered pump would be BS, IMNSHO.
Heck, just get a UPS.
Frankly, however, there isn't anything wrong with waiting until the water is
quite high before switching in the battery operated system.
The AC operated system has unlimited power available and does its thing
keeping the basement close to bone dry.
When you are running off the storage battery your goal is just to keep the
water from rising above the floor level. When the power goes out you just
don't know how long you will rely solely on the storage battery. But with
a higher water level it takes less battery energy to pump the water out.
And,usually, the higher the water level the less "new" water comes in.
That's a very good point. My AC sump pump ran fairly often, but when
I raised the float level one inch, I cut that down by 80 or 90
If the water outside is high enough to turn on the sump pump, the pump
will go off because it takes a while for the water to get into the
sump, but it won't stop running in general until the water drains out
of the land outside and into a stream, or further down into the earth.
Why waste a battery trying to keep the water 6 inches below the floor
if it is not going to rise to more than 4 inches below the floor
Thank you John. Your first sentence about the UPS struck me as
silly**, but the rest of your post is right on. If I had put in a
battery backup, I was going to put it on the bottom, and probably make
the float high. But I could just mount it atop the current pump. (I'm
still trying to fit all the pipes in under the plastic sump lid, so
that might prevent this choice, but it's a good choice otherwise.)
**Although not if you meant that one could probably take a standard
UPS that came with little batteries and hook the electrical part to a
big marine battery, such as used by battery sump pumps.
It would be bettter if the pump would work even if there was AC. This
house is 27 years old ,and this has only happened once, but that once
my 1/3 HP sump pump was going full blast and the water was still
overflowing the sump. So if one is going to put a back up pump in,
it's best if it will run when the other is also running.
That's a good idea. Maybe both pumps should run whenever the other
one does. It would take less time to empty the sump, but the battery
would be cycled a little bit more. I wonder if that would shorten the
battery life, and how much.
Of course this all depends on how often the pump runs now.
I would think that would be ideal. The original pump handles everything
until the water gets that high and then the backup kicks in. If it can't
pump the water out as fast as it is coming in, a couple of feet will not
Use a pump with sealable connections for hose or pipe at
both the inlet and outlet.. The inlet pipe going into the
sump would have a foot valve so it doesn't lose prime.
Just about any water level switch can control it. You want a
charger that will regulate to a trickle charge when the battery
reaches full charge. Use a "deep cycle" battery.
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