Technical > Home Improvement > Sump pump w/ battery backup

Sump pump w/ battery backup

reply to dick white
I suggest two pumps.

It sounds like your point of failure was the pump itself--having a battery back up wouldn't have done much for you in that case.

My sump pit has two identical Zoeller pumps in it, one set to turn on at slightly higher water levels--to deal with huge volume of water coming in, or #1 pump failure.

I'm lucky in that my pumps have not turned on (or the pit even been damp) since I corrected downspout and grading issues, but I feel good knowing they are down there.

For electrical backup I bought the largest marine battery that walmart carries and a 1500W inverter. When the power went out yesterday I plugged the pumps into that (not that they ever ran). If I wasn't going to be home for the day/night/weekend, I'd plug pump #1 into mains and pump #2 into the inverter ... that way if pump #1 has no power and the pit is filling, pump #2 can turn on using the back up power.

I've never had to test the setup, but I know that it will run about 50W worth of CFLs, plus my FIOS ONT + Router, plus laptop chargers for well over 4 hours--and that was the point the mains power came back.

Worst case scenarios, get two marine batteries... one can be charged by a fast-idling car while the other runs your pumps... I figure a single pump can run continuously for at least an hour from a fully charged battery, if not longer.

One thing to add... since the marine batteries are flooded cell or whatever it's called, you need to charge them outside! I charge mine after each use using a regular car battery charger. If it's been a few months, or a storm is coming, I'll put it on the charger before hand (the charger I have is automatic, so it monitors the voltage level and decides when the battery is fully charged, if the battery has been sitting 6-8 months it usually tells me it's "90%" charged when I start, and at a 5A rate it will claim fully charged within an hour.

If you wanted a less messy setup you could spend the cash on a large expensive AGM sealed battery, you could charge that one indoors.

I'd definitely test that battery/inverter system with the pump to at least make sure the motor inrush won't kick the inverter off line.

reply to dick white
Thanks, bemis, there may or may not have been pump failure, won't know until the power is back on and we can test it. We were worried about what would happen if the power went out during the worst of the storm, so we were down there putting everything on the floor onto shelves and tables and other things to try and redirect any overflow to the drain. The pit was only partly full at the time, about normal when the french drains are doing their thing. Then the power went out, and an hour later the pit was full, barely overflowing into our catchments, but we failed to consider that the "underground" water level all the way back through the french drains was now just as high. We finally figured that out when the water started flowing into the utility area from the finished area, not the other way around.

Your idea of redundancy with comparable 120V pumps is worth considering, but the battery-based systems use a similar effect except that the secondary pump has a 12V motor with a trickle-charge setup for the battery pack. But some of the online reviews suggest that some of these 12V pumps don't have the power or capacity to keep up with a serious deluge. That's why I am hoping the assembled wisdom here will weigh in with opinions on various brands and configurations. I might do it myself, in which case I'll want to buy the right stuff. Or if I get a plumber or contractor to do it, I want to be able to negotiate for what is best, not what is most profitable for them to sell.

thx
dw

reply to garys_2k

reply to dick white

reply to dick white
We have a Zoeller Basement Sentry #507 system in our house and here's how it works:

* The regular sump works like normal.
* I've got a 12v Deep Cycle battery and a trickle/float charger.
* There is a smaller 12v pump that sits above it with a separate float.
* Should the water level rise above the normal pump the 12v pump kicks on and pumps the water out. There are check valves in both the 12v and 110v pumps output so one won't fill via the other.

It seems to work well. I "tested" it the last night and it was able to keep up with the inflow quite well. Other than that I think it would help in your situation but the question would be how long the battery would last.

reply to dick white
When I purchased my current home had a finished basement with only a single zoeller sump pump installed.

That was my first project to replace it with a Watchdog Big combination pump. »www.lowes.com/pd_120110-84862-BW···cetInfo=

Now I have a primary electric and battery backup. Backup unit will kick in case of power outage or a problem with main pump. Can say the watchdog is much quieter than the zoeller.

reply to dick white
Power was restored today and the pump immediately emptied the rest of the sump pit. But it is an old pump, so we may replace the whole kit'n'kaboodle anyway rather than just add a backup. That Watchdog Big Dog looks interesting, nice tight arrangement to fit both into the same smallish sump, easy assembly of the piping, however don't like the wet acid battery but there is information suggesting an AGM battery is compatible with the unit's electronics. Still more research, hopefully Sandy's next of kin will stay out until them.

dw

I have only been here a few months. So far the battery has only required water added, about every 6 weeks. Am kind of concerned about reports of it dieing in 3 or 4 years. So far other than me testing it the backup pump has never been used.

If I remember the documentation you can use other type deep cycle batteries but the low water sensor won't work.

reply to dick white
How long would you expect a battery on a sump pump to last in hurricane/flood conditions? Here is a hint, not as long as the power outage.

I suggest "Wayne ESP25 12-Volt 3300 Gallons Per Hour Battery Back Up Sump Pump System" It is the best for you.

The battery for watchdog is supposed to last like 7.5 hours continuous use. Under normal conditions sump pumps don't run continuously.

After battery dies generator can be used to power the main pump and recharge the battery. Guess you could yank car, boat, or lawn mower battery if really desperate.

BTW I think you can connect two batteries up.

I have yet to see my backup system operate in a power outage but under the worst rains so far the main pump turns on about every 15 minutes for about 20 seconds. So maybe and I am just guessing I could go days on battery power only. Granted this is not what the OP was dealing with.

Your only other option would be water powered sump pump. This would work nicely if it can keep decent water pressure and be able to keep up with flow.

reply to dick white
During Sandy in Annapolis my section of the neighborhood lost power for about 18 hours. Next-door neighbor has a 110v sump pump with a 12v battery backup. By nightfall Monday we had 4" of rain and their basement was flooding due to the battery powered pump being overwhelmed by the water volume, and the battery being depleted after a few hours of running.

I ran a long extension cord to their house to get their main pump running again.

Anyway, the moral of the story is that the type of pump backup you choose depends entirely on the site specifics--how much water could possibly flow into your basement, what would be destroyed if it were to flood, etc.

Another thing to consider is to have something like this on hand:

»www.northerntool.com/shop/tools/···00380049

Moral of the story is that you should have a MAIN type of backup for everything (Generator) and focus your "maintenance" time on that generator.

When an event like Sandy occurs, you're sure it will work.

I can understand the battery as a "bonus" to use it while you have the generator turned off to save fuel.

reply to dcurrey

reply to dcurrey