I had a client ask me how long a 12v battery back up system would last if the power would happen to go out. I said I wasn’t fershur , but I would ask “my people” and have an answer for him soon. Thanx in advance… I know alot has to do with the amount of water that is entering the pit & how much the pump is running to draw power. I am just looking for an approximate under standard conditions ( perimeter drain tile is only feed to sump).
You need to look at the pump info and see how much it is drawing , before you get a reasonable answer.
You have to divide the Amphour rating of the battery by the amp rating of the pump assuming a fully charged and like new condition battery.
I think a water powered secondary pump is a better choice.
3-7 hours of continuous use.
It would probably last the night if it were going off every few minutes or so.
It’s a better choice if you have water supplied by a public utility. For us homeowners with private wells it’s the bucket brigade if you don’t have a battery back-up system.
Josh …i had one in my last house and the Manufacturer said 8 hours of continous use…i never tested it for that long though, and another thing you have to remember with them is You have to replace the battery every 5 years or so using a heavy duty deep cycle marine type battery…at least i did, but i was happy with the system over all…jim