Terribly neglected deep-cycle battery

April 16, 2019 5:53 AM

Four years ago, I installed a sump pump in my basement that can be powered by a deep-cycle marine battery. I little while ago, I discovered that the system’s manual advises topping off the cells with fresh water monthly, a regimen of care that I’ve never undertaken. The attached battery monitor/tender hasn’t given any alerts despite my neglect. Can I reboot my care of this battery? How to start over? Or is it best just to replace after so long, given the stakes?
posted by Admiral Haddock to Home & Garden (3 answers total)

First, bring a flashlight with you and take the caps off and look at the electrolyte level in there. it's possible no action is needed.

next, if you do need to add water, add enough distilled water to cover the plates. you don't want to put any extra minerals in there.

If the charger is the type that is also a "maintainer", there shouldn't really be a problem.

if you are really worried about it and have the time to babysit it, you could route a hose into the sump and see how long the pump will run when unplugged. if it runs shorter than expected, then it should be replaced.
posted by ArgentCorvid at 6:34 AM on April 16, 2019 [3 favorites]

Consider the cost of sump pump failure, in water pooling in the basement and all that entails. Then consider the cost of replacing the battery. You may sleep better with a fresh battery down there, and just consider the money paid as the cost of insurance. In addition, if you might have a rare serious storm that cuts power for days, having the older battery set aside as a spare may be a good idea.
posted by Midnight Skulker at 8:34 AM on April 16, 2019 [5 favorites]

+1, I would be thinking of swapping out even a perfectly well maintained four year old lead acid battery due to age alone if it was used for any sort of mission-critical application.
posted by Larry David Syndrome at 4:10 PM on April 16, 2019