Sump Pump Battery Back Up - Suppliers?

[Richard Faulkner]

Hi,

One of my semi basement flats is subject to flooding when we have heavy rain. It seems that the water table rises and the water pressure forces it into the flat in one corner.

About 3 years ago, we dug a sump outside the flat, (outdoors), and put an electric sump pump in it. This worked fine for 3 years, then we had another flood - the pump had failed.

We've fitted a new pump, but I would like to fit a battery backup to cope with possible future failures, which could include power.

I can find a few in the US, but none in the UK - I've been Googling for about 3 hours.

(Whenever my other half tells me she cant find something after hours of Googling, I usually put a few search terms in and find what she is looking for - so forgive me if that happens here).

Regds

[meow2222]

theyre called UPSes. But they dont address the mechanical pump failure mode.

NT

[Ed Sirett]

What rating is this pump? I take it that the pump's power supply failed before/at the critical moment? Why wouldn't an off the shelf UPS of sufficient rating not work for you?

[Grunff]

I think you need to consider a couple of points:

- What pumping rate is required?

- Do you need the pump to auto-start?

If you need a high pumping rate, then a petrol pump such as:

sense (and is really your only option unless you have a big bank of batteries. However, this won't auto-start.

If you only need a modest rate of pumping, then a boat bilge pump would be perfect, such as:

[Andrew Mawson]

Richard,

When we had to have a sump pump some years back at a previous house, I fitted a counter to show me how often it was going. This let me keep a check on functionality -- no increment = no pump !! (or drought )

A few counters here

(ok there mine I confess

AWEM

AWEM

[Richard Faulkner]

We've put an off the shelf unit in, and I was considering putting in a second off the shelf mains powered, a bit higher than the first. This is on the basis that they are both unlikely to fail at the same time, and the second one shouldnt be used much, or at all, while the first is functional.

However, as you dig deeper into these things, you realise that there is always the possibility of mains failure, hence battery backup.

They obviously have more experience of basement living, and flooding, in the US, as there are a few suppliers - Hydrostat and Wayne, but they are

120V AC to 12V DC systems.

Regds

[Richard Faulkner]

I would propose 2 pumps, one higher than the other. Hopefully, 2 mechanical failures wouldnt happen at the same time

[Richard Faulkner]

Might do the trick - bilge pump connected to marine battery, permanently connected to sophisticated battery charger, (not sure what it needs to be, but it needs to stop charging when the battery is full).

[Grunff]

That'll be one of these:

[meow2222]

no problem, just put a 240 to 120 convertor in front, then the ups, then a 12v to 24v rotary convertor, then the pumps... and wonder why the whole lot is drawing 1kW for a 100w pump.

I think your idea of 2 pumps is good, as long as you do a maintenance check on them every so often. Otherwise they'll both be dead sooner or later.

A ups with some self testing/warning would be good. None of that kit will have very long life, pump nor ups.

NT

[Richard Faulkner]

I was thinking of something like a 130Ah marine battery, (or certainly

60 -70Ah).

Any ideas - is trickle charging OK if the battery isnt being used at all for most of the time?

[Lobster]

Is it really worthwhile though - I mean, consider how often you are likely to have a power cut (in presumably an urban area?), then add in the likelihood of the rain being bad enough at the same time, for long enough, to cause a flood?

Sounds a sensible idea. Ideally, wouldn't you also want some way of easily identifying that pump A had failed (and required sorting) and that the backup B was now doing the job?

David

[dennis]

That's easy.. just put an egg cup (or similar) so it fills just before pump two switches on. If there is water in it then pump one has failed.

[Grunff]

Oops, I didn't spot the 9Ah limit on that charger. You can get similar chargers for higher capacity batteries.

Yes, the battery will be fine, but will have a standby life of 2-3 years. You'll need to budget on replacing it at that kind of interval.

[Sponix]

How about a 12v bilge pump, as used on boats?

I'm sure that you can buy 'em with float valves in so that they only trigger in the prescence of water.

All you'd need do is rig up some sort of trickle charger to keep the battery topped up.

sponix

[Sponix]

Something like this, but with a water sensor/float valve/whatever:

[Sponix]

More pumps 'n' float switches here:

[Pete C]

How did the first pump fail, is the water clean or dirty?

Also how many litres/min do you need?

cheers, Pete.

[Owain]

Depending on how quickly the sump fills under heavy rain, a more long-term reliable solution might simply be a battery-powered float alarm in the sump, above the normal max level, and a stirrup pump or one of those submersible hippo pumps used as required (on a genny or car battery if needed).

Even without a working pump, an alarm at least allows the fire brigade to be asked nicely if they can come and pump you out - most will if they're not out on an emergency.

Owain