PDA

View Full Version : Battery back-up for a sump pump


jv12375
Mar 10, 2014, 02:23 PM
I'm trying to set up a back-up power supply for our sump pump and had a quick question about the configuration. I have a deep cycle battery, trickle charger, inverter & relay. I'm confident the electrical tolerances are correct, but I wanted to confirm I had the connection order correct?

Outlet=> relay => trickle charger => deep cycle battery => inverter => sump pump.

Any help would be greatly appreciated... Thank you!

smearcase
Mar 10, 2014, 02:38 PM
Here is a typical schematic.
Image:SUMPPUMP.jpg - wikiHow (http://www.wikihow.com/Image:SUMPPUMP.jpg)

jv12375
Mar 10, 2014, 02:51 PM
I saw that, but his configuration order doesn't make sense. He recommends connecting the battery directly to the sump pump?

ballengerb1
Mar 10, 2014, 06:11 PM
Battery sump pump backups most frequently use a small 12 v pump motor in addition to your 120 vac pump. I don't picture a 12v battery connected to an inverter lasting very long at all.

smoothy
Mar 10, 2014, 06:34 PM
I would get one already designed for battery backup... and you can upsize the deep cycle battery if you need the extra time. As was mentioned while you can use an inverter to power the pump for short periods... its way more efficient to eleminate the losses of an inverter and get one desinged for a battery backup.

smearcase
Mar 10, 2014, 07:11 PM
jv,

If you read further down on that link, it discusses the trickle charger. I personally don't want a battery charging 24/7 as needed in my basement. I purchased a 1500W inverter which I can hook to my truck battery (have to let the engine run) so that I could operate the sump pump if ever needed which is not likely with my situation. During Sandy storm I had no backup and kept watching the pump but it only ran about twice, and we did not lose power. I can use the inverter to power other small loads (hot plate, small toaster oven, small freezer-off and on if it becomes necessary. Hoping to never have to use it.
Anyhow, I didn't notice that the schematic I gave you didn't include a charger but they discuss it in that same article.

smoothy
Mar 10, 2014, 07:18 PM
I think I see smearcases point now...

And having decent sized inverter handy can be of use for a number of things (just the more critical one or ones)... Including the rare event happening. (just be aware you need to be able to handle the startup surge and then some with the capacity)

Before I acquired a pair of generators I did just that... except it wasn't with a sump pump. ( I don't need one).

However a trickle charger will cause sulfation left on long term...what you want is a battery tender which is more like a smart float charger.