I am a novice in terms of dealing with AGM batteries. I have a simple question to ask everyone here: how can I tell if my AGM batteries are about to be out of service. My batteries seem to be charged to full with a very short time but run out of juice very quickly. Does it mean the batteries have few cells left or they are reaching the end of their charging cycles?
How can I tell if the battery is going out of service
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Seminole Wind
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yes, both of you observations of quick to come to a "full" charge an running out of juice quickly, (especially if you are referencing a significant change from how they used to perform) are indications considerable degradation and reduced capacity.
there are a couple ways folks "judge" when it is time to replace. the simplest being is when the capacity has reduced to the point they wont run the loads you have for the legnth of time you want.
then i have read a couple "specs" that can be used to determine how toast batteries are. the actual numbers elude me so it is something you would need to look up. but when the charge efficiency drops off to a certain point expressed in % is the way i saw it. so for example if you have to put 100 amp hours into a battery to recharge after using 50 amp hours i would call that 50% efficiency. that, i would think would be a pretty toasted battery. another method i read about was "end amps" once a battery was fully recharged, how many amps keep trickling in. the spec i saw was if the end amp were more than a few % of the amp hour capacity that indicated being worn out. both of these i believe will really only indicate worn out from use. but might not indicate toast due to sulfation. unfortunately there really isnt any way to recover sufated AGM batteries like you can (to some extant) with flooded lead acid.
there are a couple ways folks "judge" when it is time to replace. the simplest being is when the capacity has reduced to the point they wont run the loads you have for the legnth of time you want.
then i have read a couple "specs" that can be used to determine how toast batteries are. the actual numbers elude me so it is something you would need to look up. but when the charge efficiency drops off to a certain point expressed in % is the way i saw it. so for example if you have to put 100 amp hours into a battery to recharge after using 50 amp hours i would call that 50% efficiency. that, i would think would be a pretty toasted battery. another method i read about was "end amps" once a battery was fully recharged, how many amps keep trickling in. the spec i saw was if the end amp were more than a few % of the amp hour capacity that indicated being worn out. both of these i believe will really only indicate worn out from use. but might not indicate toast due to sulfation. unfortunately there really isnt any way to recover sufated AGM batteries like you can (to some extant) with flooded lead acid.
Weight said:
The OP got about 5 years of use so that's not really a 'short life'...
But yeah they may be circling the battery 'grave yard' as we speak.
broken ed
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Batteries Plus, now known as Batteries + Bulbs, will perform a free "capacity test" not to be confused with a "cold crank amp test" that would be done for automotive batteries.
They did this for me on six deep cycle batteries, one was at 9%, the best one was at 86% (if memory serves), 86% they consider still good. They recycled the bad batteries for me, also at no charge.
They are, of course, hoping you'll buy from them, which I was so grateful for the service I purchased two replacements, but you don't have to.
This test is time consuming, be prepared to leave your battery with them for a day or two, if no one is ahead of you in line for the test. I took two in at a time until I was done so I had the others to use while the others where being tested.
They did this for me on six deep cycle batteries, one was at 9%, the best one was at 86% (if memory serves), 86% they consider still good. They recycled the bad batteries for me, also at no charge.
They are, of course, hoping you'll buy from them, which I was so grateful for the service I purchased two replacements, but you don't have to.
This test is time consuming, be prepared to leave your battery with them for a day or two, if no one is ahead of you in line for the test. I took two in at a time until I was done so I had the others to use while the others where being tested.
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