The Ford Barn - View Single Post

Joe K · 11-19-2019, 09:56 AM

In a different application, (battery powered back-up sump pump) I have found that "smart" chargers/battery tenders are not so (smart.) One can tell if the battery is overcharged using the charger by loss of electrolyte. If you find the electrolyte low and have to fill up then your battery charger is "boiling off" the water in the electrolyte.

The owner of this installation (neighbor-not me) is into Boxter cars and keeps his collector car battery topped up with what he considers a high quality Mercedes brand battery tender.

On my attributing his sump pump short battery capacity to "low charge using the built in battery charger" he suggested we try the Mercedes unit on his sump pump. The result seems to have sufficient battery capacity for 8 hours of sump-pumping (well above what one would expect) BUT the high end charger "boils off" his electrolyte over a period of 5 or 6 months requiring a top-off. (automated, the system gives alarm on low electrolyte.)

I suggested adding a timer to turn the charger on perhaps 20 minutes a day.

We're doing this now - I don't have a result on either battery capacity or boiling down yet.

Joe K

11-19-2019, 09:56 AM	#17
Joe K Senior Member Join Date: Jul 2010 Location: Cow Hampshire Posts: 4,188	Re: Battery charger???? In a different application, (battery powered back-up sump pump) I have found that "smart" chargers/battery tenders are not so (smart.) One can tell if the battery is overcharged using the charger by loss of electrolyte. If you find the electrolyte low and have to fill up then your battery charger is "boiling off" the water in the electrolyte. The owner of this installation (neighbor-not me) is into Boxter cars and keeps his collector car battery topped up with what he considers a high quality Mercedes brand battery tender. On my attributing his sump pump short battery capacity to "low charge using the built in battery charger" he suggested we try the Mercedes unit on his sump pump. The result seems to have sufficient battery capacity for 8 hours of sump-pumping (well above what one would expect) BUT the high end charger "boils off" his electrolyte over a period of 5 or 6 months requiring a top-off. (automated, the system gives alarm on low electrolyte.) I suggested adding a timer to turn the charger on perhaps 20 minutes a day. We're doing this now - I don't have a result on either battery capacity or boiling down yet. Joe K __________________ Shudda kept the horse. Last edited by Joe K; 11-19-2019 at 10:02 AM.