Poor AGM Battery Service Life

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Aug 30, 2004
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Battery was manufactured in 11/2017 and installed the same month.

Car is driven 4-5x/week and battery is trickle-charged twice a month.

Vehicle application does not require AGM.

Not seeing the benefits of AGM here. A conventional battery would have provided the same service life at a lower cost.
 
Last year in March 2020, I install a brand new AGM Power Star from O'reilly. The car was not driven very much except for playing musical chairs with the street sweeper and after 7 months it had a dead cell.
 
thats a smaller weaker battery to start with + since its sealed its life begins then + IF it sets unused- uncharged its deteriorating + sealed batteries loose fluid in hotter climates that cant be replaced. getting a fresh as "strong" for its size as physically possible is best. girlfriends base mustang in the 80's would not start in very cold windy locations until it warmed up, the cure was a same physical side stronger buy costlier battery!! extreme heat kills as well as a friends small auto parts store sold more batteries in the summer in PA.
 
Interesting. I have been a bit worried about the AGM battery in the 2015 Mini that I bought half a year ago. The battery, the factory BMW-branded AGM, is original and the car had been barely used for several years. It had only 5k miles on it when I bought it. The battery is however going still strong. I have heard AGM batteries can fail rapidly.
 
I have seen cars that call for a 51r wear the battery out quickly. Sometimes the tray has a spacer that can be removed and a size 35 or bigger can be installed. Also agm batteries take a higher charging voltage than standard lead acid. If a agm battery is not charged at the higher voltage battery life decreases.
 
how m
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Battery was manufactured in 11/2017 and installed the same month.

Car is driven 4-5x/week and battery is trickle-charged twice a month.

Vehicle application does not require AGM.

Not seeing the benefits of AGM here. A conventional battery would have provided the same service life at a lower cost.
how much faith do you have in this application?
 
The 51R is a very small battery. Just be glad you don't have the 151R :D

What is typical battery life in California? :unsure:

3 years seems about right where it's warm year round. Up north, a battery will usually last about 5 years. I think Bosch-branded batteries sold in the US are Exide.
 
I have seen cars that call for a 51r wear the battery out quickly. Sometimes the tray has a spacer that can be removed and a size 35 or bigger can be installed. Also agm batteries take a higher charging voltage than standard lead acid. If a agm battery is not charged at the higher voltage battery life decreases.
I have a 10A fused lead off the positive terminal to the alternator, a sense wire perhaps? Vehicle calls for an AGM and I replaced it with such. I bought the Kia with 48k on the clock and what I imagine is the original Solous battery, it made it to 90k (760CCA). I went with an O'reilly's (East Penn)
 
I had to replace the AGM battery in my motorcycle a few months back. It had a rating of 30 amp hrs, 430 cca's. I kept in on a battery tender any time it was in the garage. It was subjected to heat and vibration. It lasted almost 6 years to the day. The battery cost me $109, shipped to my house. I don't know what one for a car would cost, or what size you would need. And keeping it on a tender might work if the car was garaged, and only used once in a while. For a DD it might not be practical, but if you have or are thinking about getting an electric car , it might get you trained.,,,
 
the only agm I’ve replaced was 8 months old when I bought it. It’s harder to find fresh ones in a pinch. I rolled the dice, it failed a few months before 36 months, and AZ gave me a new one. Ive got a 5 year old H8 in the f150 an an H6 which must be around 8 in my daughters s60. I’m eyeing one for the Lexus - looks like I have to order something to get a reasonably fresh one.
 
i must use efb or agm, i am angry because there are no service openings, imho some water has been lost. i wish i could check the level..
 
It's who makes the AGM not being a AGM. My '16 Equinox, OEM AC battery bad at 3 yrs. . OEM AC in my '11 Tahoe got pulled at 7 yrs. due to age only and not wanting to risk a no start at sub zero temps. . It's in the garage on a BatteryMinder and saw lighting duty in my camper this summer.
AGM in one of my snowmobiles, OEM Yuasa, and the OEM AGM battery in my Harley got replaced at the age of 10 yrs. . And not due to a no start but due to their age and not wanting to get stuck. Used the maintained sled battery to jump my dead JD mower last week as it's great for portable 12v power when working on trailer lights.
I've been using Odyssey brand for replacements whenever possible. Just put one in my Generac stationary whose 3 yr. old AZ just tossed a code in it.
 
I pulled my Hyundai factory heavy AGM battery for a light AGM for performance driving. It made a difference in handling, I could no believe it made that much difference. The first one I burn up in 2-3 months in a blazing hot turbo engine bay, heat soaking under the hood. I did some over the top insulating and it keeps the battery cool now. 12 lbs and $109 @Batteries Plus and one warranty they honored when I cooked it to an early death.
Before and after shots. The car still starts great at 20F. When we get to 10 F on a regular basis here in Minnesota I will put the OEM one back in.

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the only agm I’ve replaced was 8 months old when I bought it. It’s harder to find fresh ones in a pinch. I rolled the dice, it failed a few months before 36 months, and AZ gave me a new one. Ive got a 5 year old H8 in the f150 an an H6 which must be around 8 in my daughters s60. I’m eyeing one for the Lexus - looks like I have to order something to get a reasonably fresh one.
I guess I got the record here for AGM batteries. My H8 in the Mercedes is now 14 years old. It's easy to keep an eye on the voltage so I don't sit in the car long afterwards with the seat heater/radio on and we'll see how it does this winter. Probably on its way out but I was about to get it to fully charge up to 12.5 volts last year which on my state of charge chart is about 80% of original. It's a JCI though, I heard the Bosch Exide aren't that good. My H8 is also in the trunk which might explain why it has lasted so long, no engine heat to bake it. On the other hand my other H6 battery is now about 10 years old and it's still starting fine, that one is under the hood though so we'll see. I should probably invest in a jump pack.... Or if there's a good sale on batteries this black friday, but somehow I doubt it.
 
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