This is about my old house battery, not the Fiamms nor the MK gels in my ice machine.I've been suspicious of this battery for a while, but have not used it much and had other things to worry about. I just kept topping it off.Finally got around to testing it. It went to 13.36 at the terminals while on the charger, but after I let it set for 2 hours it dropped to 11.06. It was 10.something before I charged it and I suspect that is its true resting voltage.Am I correct that this means it has a bad cell and there is nothing I can do? I like to run things by you guys before I do something like recycle big azz battery :B.Spec sheet pdf.

Remind us how that battery has been living for the last few years. ISTR you have both 24 and 12 in some way. This is a 12 I assume. What measurements have you taken or what have you seen as a performance progression over the last few years to know if this battery has been going down hill as opposed to a sudden drop?

I would charge it for two hours with 14.4VDC being applied to it with at least 20AMPS DC Current available to use... Then after the two hours of being on 14.4VDC then drop down to 13,6VDC and charge for another hour... Then let it settle down and see what you read then... This is what i do here to get from 50% charge state to 90% charge state.If I want to get to the 100% charge state I have to leave the 13.6 VDC voltage on the battery for around 12 hours...Try that before giving up on your battery...If you have been just topping it off for a couple of years then it most likely will not recover from this.... A long charge using 13.6VDC will do wonders for it... This is after you do the 14.4VDC initial charge for two hours to excite everything.... This is what is happening to my three 12V batteries connected in parallel...Roy Ken

isn't this the one, that ran your fridge, your Cat heat mat and other items, in the old van ?its dead, good only for core value at the recyle yardI will say that you worked the poor thing to death, and it died respectfully doing yoemans duty, and should be given an honorable burial fitting its demiseit died with valor working way to hard for a battery that sizeyou do realize, that each (1) of your new batteries is approx (3) of this one

AGM 11.06v after charging. Hopeless? | Good Sam Community

14 Replies

MEXICOWANDERER
Explorer
Jun 05, 2017
Do ANY of these batteries post the hundred hour rate?
Naio
Explorer II
Jun 05, 2017
Oh, did I link to the wrong datasheet?! Was doing it on my phone with fumblefingers. I do have the s12v500.
MrWizard
Moderator
Jun 05, 2017
Naio wrote:
MrWizard wrote:

you do realize, that each (1) of your new batteries is approx (3) of this one

Why do you say that? They are 132aH and it is 135aH.

OK my mistake, more like 50 percent more, i originally looked at the data for the 170

your s12v370 weighs 74# the new ones weigh 102#
and are closer to the next one down the list, the s12v500

i did not see an ampHr rating, but i did see a chart for watt Hr per cell rating for different times
Naio
Explorer II
Jun 05, 2017
JimK-NY wrote:
Why are you even thinking about this? It has more than done it job and is way overdue for replacement.

I just wanted to make sute I wasn't doing something ignorant by throwing it out. Its replacements hope to arrive this weekend.
JimK-NY
Explorer II
Jun 05, 2017
Why are you even thinking about this? It has more than done it job and is way overdue for replacement.
Naio
Explorer II
Jun 05, 2017
I think there have been a couple other times, too, over the past 10 years that I have drained it too low. At least once during the first years and at least once in the last few.
Naio
Explorer II
Jun 05, 2017
MrWizard wrote:

you do realize, that each (1) of your new batteries is approx (3) of this one

Why do you say that? They are 132aH and it is 135aH.
Naio
Explorer II
Jun 05, 2017
What happened?

Well, it has had a rough life. I bought it used, as half of a pair, 7-10 years ago. Was told they had been a forklift batteries. It tested great, then, but I had to test several to get two good ones.

I got very ill right after I bought it, and for several years I cycled the batteries when I felt well enough but that might have been once every 6 months. Maybe I topped them off some times in between.

Then, when I was building my first van, I got a 12v fridge and foolishly left it running off the two batteries. Killed one outright, but this one seemed ok (not great) so I kept it. Later, told friend who was helping me NOT to plug the microwave into the inverter to test the inverter. He did, boom went inverter.

Got a new HF inverter and I complain about it a lot but maybe it was having trouble with the battery.

Battery did all I asked of it 1st year camping, but that was not a lot. Fridge only when driving and during gas stops, heating pads, sometimes a 300w heater for 5 or 10 minutes. Second year it seemed iffy. 12 months ago, driving north, it would not run the 65watt fridge when we stopped for gas. Only when van was running. Have hardly used it in the last 12 months, and when I did it did not always work. But sometimes it was ok and because of the variability I thought the prob was the inverter.

Still, when I realise how long I have had it and what it has been through, I can't complain about the $75 I spent.
BFL13
Explorer II
Jun 05, 2017
Yes, RIP, but the point is to know what happened so it doesn't happen to the next one.
MEXICOWANDERER
Explorer
Jun 05, 2017
Recycle with reverance