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Saving deeply discharged Optima 51R's

cbisson

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I picked up a super clean 802a today from a member here. The batteries have never been used as the cable ends were taped over and one of the positive posts still had the red plastic cap that you have to break to get off. The 2 yellow top 51r's are showing 1.6V each. The set was built in August 2011 has 6.4 hours on it and I believe the batteries are original. Has anyone had any success or failure rejuvenating AGM batteries this old and this deeply discharged? I am aware of the "connect to a good battery" technique but is it best to start slow or hit it with 10A right away? Has anyone got any advice on how to proceed?

Thanks,

-Craig
 

jcollings

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I had some luck bringing some 4 V hawkers backup. The key thing is is not letting the charger go over 15 V as glass mat batteries do not like that. Usually an AGM charger will meet that criteria. But then again it's always a shot some have come back some have not. Also make sure they do not build-up too much heat that's another sign it's not gonna work. Also I would recommend changing to break in oil and for the 1st 100 hours and run it pretty hard under load.

Sent from my SM-G975U using Tapatalk
 

Light in the Dark

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Craig I just looked up the NOCO unit I have in my 802, and it says it has a recover mode. https://www.amazon.com/NOCO-Genius-GENM2-Battery-Charger/dp/B00CBTRMZ4?th=1

Here is what one reviewer on the site wrote:

"I bought this to replace an old "World's Foremost Outfitter" store brand charger that went kaput and managed to pull my two month old deep cycle battery down to 4 volts. I was concerned the battery was toast. I shopped for a decent two bank charger that would condition batteries to help with sulfation, and landed on this one. Based on cost and reviews I went for it.

The deep cycle battery was too dead for this charger to initially detect it, so I had to hook it up to a "dumb" charger for about 24 hours to get the voltage high enough for this charger to detect it and start charging. Once it detected it, I let it sit. It took about 48 hours to get from 12 volts to fully topped off and conditioned at 13v+, but it pulled it off, and the next day I took the boat out and got a full day of trolling off of that battery. Super duper satisfied. "
 

155mm

Chief and Indian
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Noco g7200 is the way to go,

parallel dead battery with a good battery, i use constant amp setting until dead holds voltage over night

next use the charge function on agm to fully charge battery, after full charge which may take multiple attemps because the noco is smart then use the repair function

I have saved big odyssey, hawker and optima batteries using this technique

there are some other tricks i use but it requires a Differnt power supply

this process may take a week if you babysit it, longer if you forget about it but it save a battery
 
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glcaines

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I picked up a super clean 802a today from a member here. The batteries have never been used as the cable ends were taped over and one of the positive posts still had the red plastic cap that you have to break to get off. The 2 yellow top 51r's are showing 1.6V each. The set was built in August 2011 has 6.4 hours on it and I believe the batteries are original. Has anyone had any success or failure rejuvenating AGM batteries this old and this deeply discharged? I am aware of the "connect to a good battery" technique but is it best to start slow or hit it with 10A right away? Has anyone got any advice on how to proceed?
Thanks,
-Craig
Definitely try to save the batteries. Do not try to hit it with 10A right away. Use a NOCO or other AGM friendly battery charger and as you mentioned, parallel the battery with a good battery with the charger hooked up. I've had 100% success so far. In one case with an Odyssey battery, it took several days with the parallel hookup before the battery started taking a charge.
 

cbisson

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Everyone here has given you the straight deal. This is one job you need to start, and shove it off into a corner. Take your time. Better to wait 1-2 days even longer. cant hurt. I found that recovering Optima batters is almost a sure deal, with the right charger, right hook up and TIME.
I've got the time, the patience, and will have the proper charger as of tomorrow. At $237 apiece for new Optima D51r batteries it'll be time well spent.

Thanks to all for your input.

-Craig
 

Coug

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Looks like the G7200 has been replaces with the Genius 10, a 10 amp instead of 7.2 amp charger.
If you're willing to be patient get on their mailing list, and they occasionally send out decent offers, or do things like 30-40% off for black friday. (this last black friday they had all their jump boxes about 1/2 price)
 

kloppk

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I did some battery recovery on a pair of Concord 24 v batteries for my 831's using a constant current recovery technique. I used the technique documented in a Concord battery m as manual. The batteries recovered to 80 and 90% of capacity. However after 6-9 months of off and on use both died and I ended up replacing with pairs of agm motorcycle batteries.
 

M35A2-AZ

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Looks like the G7200 has been replaces with the Genius 10, a 10 amp instead of 7.2 amp charger.
If you're willing to be patient get on their mailing list, and they occasionally send out decent offers, or do things like 30-40% off for black friday. (this last black friday they had all their jump boxes about 1/2 price)
The Genius 10 is a 6v & 12v, The G7200 was 12v and 24v.
 

NATCAD

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I have used supply mode on the noco 7200 for 12-20 hours, followed by pressing and holding the mode button while in supply mode to access 'boost' mode which is IIRC 16v at 0.5 amp and then 24-30 hours to completely bring the optima back.
 
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