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Discussion Starter #1
Tried to start the bike today but the battery was dead. Rode it just a few days ago with no problems w/good voltage. Key was off and removed, nothing was on.

Frustrated with the AGM battery - I took it out, checked voltage 8.6 and falling slowly. Knowing the problems with low acid level in a wet cell, I pried off the caps on the 'sealed' AGM battery.

Looking in the holes, the glass mats were dry. I added water, waited + or - 10 minutes, checked voltage ... and 12.8 w/o charging.

The battery is charging at 1 amp for a few hours, I'll try it in the morning.

Anyone else ever seen this or take the caps off a sealed battery?

DT
 

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I'm not totally sold on the idea of a sealed battery except for the fact it eliminates the seepage problem. How old is the battery?
 

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Discussion Starter #3
18 months? I wonder if my R/R is overcharging. I did some research on charging AGM's. They are much more sensitive to overcharging than lead acid types.

DT
 

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I have that same battery in my bike...for about a year now. My R/R started going bad. It would not regulate the voltage when the bike was started and would go up to as high as 19.4V. After running for about 5 min the regulator would click and start working fine after that. The whole time I had that regulator on my bike it would charge at 13.8-14.5V. I replaced it recently with a Ricks Motorsport regulator ($98.00) from Dennis Kirk and it will not charge any higher than 13.5V. My AGM Sears battery has worked flawlessly through all of that. I think maybe your regulator my be going out and overcharging the battery at 14-15V? The charge does not need to be any higher than 13.5V ever! Is your reg. still over the Goat or has it been relocated or degoated? I hope this helps.....Oh yeah my bike is an '86 with a new Ricks Motorsport stator too as of a year ago.
 

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Love My Baby
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I've got a Sears AGM battery too, 2 years now and running well. What kind of charger are you using? How often are you charging it? I had a problem with my wet cell when I was trickle charging daily, seems each time you connect the charger the charging voltage starts high before it goes into trickle mode, and that was enough to loose a little fluid thru the vent tube. But on an AGM MF battery, there's no vent tube. I have only charged my AGM battery four times in two years, and only because I hadn't rode the bike in a while and the resting voltage was a touch lower, but still above 12 volts. You could be overcharging or your R/R could be out.
 

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I'm still going with my theory that these higher voltage AGM batteries are causing more heat to be generated in the R/R by shunting more power to ground, leading to R/R failure and taking the stator with it by association.
 

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I'm still going with my theory that these higher voltage AGM batteries are causing more heat to be generated in the R/R by shunting more power to ground, leading to R/R failure and taking the stator with it by association.
the stators were going bad before the AGM batteries were widely used.
 

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I'm sure they go bad on every bike eventually. I'm just trying to gauge if there is a link between AGM and early R/R failure. My 1990 is still going strong on the origional stator and R/R. I'm reading about alot of stator failures on this site and a good number are on newer bikes that switched to AGM. Many on this site refuse to even give this possibility any thought.
 

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If you maintain a wet cell battery properly and keep electrical connections clean or keep the bike inside a wet cell would be fine. but most don't.
 

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I've put 11,000 miles on my 1989 since installing an AGM. Original stator and R/R
 

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Discussion Starter #11
I Agree

If you maintain a wet cell battery properly and keep electrical connections clean or keep the bike inside a wet cell would be fine. but most don't.
I went 7 years on a DieHard gold wet cell before the AGM.

DT
 

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i think i may be having a similar problem. I installed an AGM about 18 months ago. My bike runs around 12.5. I can't tell specifically because of the vibration on the analog meter. It takes a charge from a Battery Tender Jr, no problem. After a charge, it starts well, as long as I ride it every few days. If I let it sit for a couple of weeks though, it wont fire up. It tries, but just doesn't have enough to do the job. I charge it overnight, and it's ok again.

I'm going to open up the cover tomorrow AM. Maybe my cells are dry too
 

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I opened it up, 2 dry cells. I refilled them and charging
 

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Discussion Starter #14
Here's a follow up a few weeks later...

After popping open the AGM and adding more water, it's been fine - takes and holds a charge. I did some research and found other folks have run into the same problem with AGM's drying out and not holding a charge.

Time to check my R/R.

DT
 
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