AGM battery repair?

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Jonny G

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We have an AGM 12v battery for our trailer that has gotten to the point of not holding a charge. Battery is less than a year old and I think we let it run down to the point of not being able to charge. I have heard these can be repaired or "tricked" into charging again. Does anyone have any advice on how to do this? Thanks!
 

Jonny G

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Gorham, ME, USA
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Jon
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Gertig
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No luck. Tried several methods before taking it into Batteries Plus Bulbs. They Couldn't get it to charge with their equipment either.
Guessing it's totally dead, which is unfortunate.
 

OffroadTreks

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What kind of charge controller do you use to recharge it? And how low have you been draining it?

Dipping below 50% charge will shorten the lifespan of an AGM, if you want a lot of cycles, don't discharge lower than 60%.
 
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Jonny G

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Gorham, ME, USA
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The trailer came with a Noco Genius G3500 charger. The problem that was my fault, was storing the trailer at a storage facility and not pluging in to maintain the battery. We left it for about 3 months without charging while working on moving to a new house.
Also tried a Schumacher charger that had AGM charging capability. Anyway, voltage was at about 4.5 when I started the whole process. Was able to get it up to about 6.5 volts by "tricking" the battery using another in parallel, but still too low for the charger (for the Noco and Schumacher) to recognize when by itself (guessing this is what happened). Maybe an older charger that won't shut off when too low voltage is recognized, or when batteries in parallel reads a particular voltage? If there ever was such a thing?
I'm guessing you're right BoldAdventure, the battery dipped well below 50% and it's gone now after sitting for so long.
 

VCeXpedition

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If you have or know anyone with an Optima charger, I have seen those recover batteries that were severely discharged, and they profess they are better at that than any other charger.

We use those exclusively now for all of our 12volt batteries that we use to power test equipment.

Sent from my SAMSUNG-SM-G935A using OB Talk mobile app
 
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Jonny G

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Gorham, ME, USA
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Jon
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Gertig
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No one I know of with an Optima charger. Is it the Optima 1200 you're talking about? If so, do I bite the $200 bullet with hopes of it working, or the $172 bullet for a new Duracell? Or even more for another brand as you mentioned?
I suppose I could return the Optima charger if possible. Not sure that feels right... haha.
 
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VCeXpedition

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Yeah, if you don't have an ongoing need for one, they are pricey. Buy a decent battery with a warranty and see if you can make it outlast it's warranty.

Sent from my SAMSUNG-SM-G935A using OB Talk mobile app
 
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OffroadTreks

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Yeah, if that thing won't take a bulk charge and hold it, it could be perma dead. 4-volts on a 12-volt battery sounds super dead.

But just sitting shouldn't have drained your battery that badly. I forget what the standard discharge rate is, but you might have something else in your trailer discharging it.



I'd just replace it and be done with it. Get yourself a batter tender for storage.