2003 AGM Battery
Thread Starter
Le Mans Master
Joined: Feb 2003
Posts: 6,683
Likes: 144
From: Memphis Tennessee
2003 AGM Battery
Well, last Thursday I went out to the AE, turned the key and got the dreaded "clicks." I was just getting the mileage to write down for another project, so I did not NEED to drive her. I was headed out of town for a few day, and after my return, I have charged the battery some five times.
Oddly enough, I think it may be okay. I cannot believe it, and will probably put it through the test of lights on and all before I trust it. I am amazed though at this point.
Now for the reason for posting: How in the world has this battery lasted seven years, and then totally discharged and coming back to life. Did I miss something on these glass-mat batteries?
I am sure someone knows much more about all this than me.
Thanks ahead.
UPDATE ON POST 9
Oddly enough, I think it may be okay. I cannot believe it, and will probably put it through the test of lights on and all before I trust it. I am amazed though at this point.
Now for the reason for posting: How in the world has this battery lasted seven years, and then totally discharged and coming back to life. Did I miss something on these glass-mat batteries?
I am sure someone knows much more about all this than me.
Thanks ahead.
UPDATE ON POST 9
Last edited by ALLEGRO; Jan 30, 2010 at 04:13 PM.
Tech Contributor
Joined: Dec 2003
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From: Horncastle Lincolnshire, England
2023 C5 of the Year Finalist - Unmodified
I'd say 7 years from an AGM is a good run. Gradual discharge from the C5 is enough to run it down unless its on a tender. I killed my Red Top shipping the car to England but once it died no matter how many times I recharged it didnt last. Not sure that it will be reliable now that its starting to run down. I'd say invest in a replacement so you dont get let down.
Last edited by DeeGee; Jan 24, 2010 at 06:49 PM.
Thread Starter
Le Mans Master
Joined: Feb 2003
Posts: 6,683
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From: Memphis Tennessee
I'd say 7 years from an AGM is a good run. Gradual discharge from the C5 wi enough to run it down unless its on a tender. I killed my Red Top shipping the car to England but once it died no matter how many times I recharged it didnt last. Not sure that it will be reliable now that its starting to run down. I'd say invest in a replacement so you dont get let down.
Race Director
Joined: Dec 2000
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From: San Diego CA
My OEM AC Delco AGM battery was 7 years old when I replaced it - not because it was dead, but because I was playing it safe. AC Delco stopped selling AGM batteries after the 2003 model year. My guess is that they did this because AGMs inherently do not like to be drained beyond a certain level and then recharged. The battery that replaced those AGMs (AC Delco Professional) can take more abuse by those who allow their vehicles to sit for prolonged periods of time.
While your AGM may start your car just fine after the battery is fully charged, it will probably weaken more quickly when subjected to normal drain levels.
While your AGM may start your car just fine after the battery is fully charged, it will probably weaken more quickly when subjected to normal drain levels.
Tech Contributor
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From: Horncastle Lincolnshire, England
2023 C5 of the Year Finalist - Unmodified
I know what you mean. My Red Top would take a charge and maybe start for a few trips but it just wouldn't hold it. In my case, I dont blame the Red Top. It took the abuse of a long trip and as Dave says, AGMs are intolerant of being discharged. Red Tops will not leak (and that was what I wanted) but they're not good for "Weekend Warriors" (or Corvettes taking 8 week trips to Europe). Interestingly, I'm less tolerant of the AC Delco that leaked even though it lasted 7 years than the Red Top or the AC Delco AGMs that died early.
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I had a Red Top in my '00 for almost 7 years when I sold the car and it was still working well - but I did keep it on a Battery Tender Plus when the car was sitting in the garage. I'm sure that helped extend the life of the battery.
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Joined: Jan 2010
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From: Plano Texas
Oldtimer
One cycle of a battery is a discharge from full charge to full discharge and a return to full charge again. Most automotive starting batteries are composed of thin plates, very porous separators, and low density plate oxides. Such batteries will lose more than half of their capacity after only a few cycles. Batteries designed for higher cycle life (such as Optima Yellow Top) can withstand significantly more charge-discharge-charge cycles without lose of capacity. If your vette sits for long spells without be operated, use a battery tender to keep a starting service battery from being discharged, or, get a combination starting/deep cycle battery like the Optima yellow top (Optima red top is a starting service battery and will loose some capacity after being fully discharged only once)
Tech Contributor
Joined: Dec 2003
Posts: 19,384
Likes: 87
From: Horncastle Lincolnshire, England
2023 C5 of the Year Finalist - Unmodified
One cycle of a battery is a discharge from full charge to full discharge and a return to full charge again. Most automotive starting batteries are composed of thin plates, very porous separators, and low density plate oxides. Such batteries will lose more than half of their capacity after only a few cycles. Batteries designed for higher cycle life (such as Optima Yellow Top) can withstand significantly more charge-discharge-charge cycles without lose of capacity. If your vette sits for long spells without be operated, use a battery tender to keep a starting service battery from being discharged, or, get a combination starting/deep cycle battery like the Optima yellow top (Optima red top is a starting service battery and will loose some capacity after being fully discharged only once)
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Thread Starter
Le Mans Master
Joined: Feb 2003
Posts: 6,683
Likes: 144
From: Memphis Tennessee
Update
Well as I stated earlier, I charged the battery several times, not long at a time, but sufficient to bring the charge-rate down. I then have left her untouch......covered and everything for over a week. I have been out of town on business.
Snow on the ground today, watching ROLEX 24 and bored out of my head. Decided to test my work and possibly head out to get another battery if she won't start.
Went out to the garage, moved the cover, opened the door. To my surprise at this point the lights came on, key "dinger" worked so at least this had my attention. Sat down, turned the key to ON but no further. Waited on all the systems to come to life and then the BIG TURN.
It cranked, and cranked well. Still don't know if I will trust the thing once Spring arrives and more drives are possible. But interestingly enough, it did come back to life, seems to hold a charge for at least a week (even some Red Tops don't do that) and started the car.
More soon.
Well as I stated earlier, I charged the battery several times, not long at a time, but sufficient to bring the charge-rate down. I then have left her untouch......covered and everything for over a week. I have been out of town on business.
Snow on the ground today, watching ROLEX 24 and bored out of my head. Decided to test my work and possibly head out to get another battery if she won't start.
Went out to the garage, moved the cover, opened the door. To my surprise at this point the lights came on, key "dinger" worked so at least this had my attention. Sat down, turned the key to ON but no further. Waited on all the systems to come to life and then the BIG TURN.
It cranked, and cranked well. Still don't know if I will trust the thing once Spring arrives and more drives are possible. But interestingly enough, it did come back to life, seems to hold a charge for at least a week (even some Red Tops don't do that) and started the car.
More soon.
