high rate charging on generator
Hi all, The batteries: 556 amp-hours of surplus acid AGM batteries 12 volt jars 105 lbs each. They are wired as two banks with balanced wiring. The depth of discharge: 12.1 volts under 425...
Forum Discussion
JiminDenver
Are you sure you could live with the other differences? AGM is heavy and the CCA ratio is something like 2/3rds. If one has the space and the springs, no sweat.
Let's suppose a given AGM is supposed to last 5-years treated correctly. Let's suppose out of those 5-years a total of three months SPREAD EVENLY over the 5-years the batteries were charged to 95%. How much lifespan would be sacrificed? I suspect less than one month.
AGM batteries can "handle" 14.7 volts charge limit from 95-98% capacity just fine. They are a battery not fulminate of mercury.
When an individual DEVOTES an AGM to dedicated low value solar charging, penalties are invoked. Some of them are unpleasant. Loss of capacity recovery is a royal pain-in-the-ass, review the Lifeline manual PDF and groan. Avoiding the use of a generator without benefit of having a very large solar array, just isn't worth it. Take this advice from someone who got their rear scorched learning the hard way...
Too late in life for me to learn exactly why but AGM hates with a passion to start from cycle low point with less than a 20% of amp hour recharge rate. I can guess the following scenario: Discharge AGM to 50% capacity. Turn off all loads then recharge at 5% amp hour capacity all day every day until charge amperage droops to point five percent amperage rating one half amp per 100 amp hours. Battery will lose 40% of it's lifespan, perhaps 25% of it's lifespan when pain-in-the-ass recovery is used. It just isn't worth it. If a 100 amp hours worth of AGM is not recharged at 20% prepare for the consequences. As in every electrochemical action, time and amplitude enters rudely stage left. A fifteen percent recharge rate is not nearly as destructive as a five percent recharge rate. Having the charge cease during no sunlight just makes things worse (if that's possible). The answer is to achieve a minimum amperage into the battery recharge of 20% AND leave the battery at 95% SOC when it's margarita time. Hitting 100% SOC is hard to do, but the top missing 5% is not Armageddon. The 5% should be made up similar to what top charging does for a flooded battery (See! The batteries have something in common).
I wish things were different, but I have to play by "their" rules, as well.
I wish John Marles (Megawatt) could come up with a large charger that could be tweaked to 14.4 volts.
Are you sure you could live with the other differences? AGM is heavy and the CCA ratio is something like 2/3rds. If one has the space and the springs, no sweat.
Let's suppose a given AGM is supposed to last 5-years treated correctly. Let's suppose out of those 5-years a total of three months SPREAD EVENLY over the 5-years the batteries were charged to 95%. How much lifespan would be sacrificed? I suspect less than one month.
AGM batteries can "handle" 14.7 volts charge limit from 95-98% capacity just fine. They are a battery not fulminate of mercury.
When an individual DEVOTES an AGM to dedicated low value solar charging, penalties are invoked. Some of them are unpleasant. Loss of capacity recovery is a royal pain-in-the-ass, review the Lifeline manual PDF and groan. Avoiding the use of a generator without benefit of having a very large solar array, just isn't worth it. Take this advice from someone who got their rear scorched learning the hard way...
Too late in life for me to learn exactly why but AGM hates with a passion to start from cycle low point with less than a 20% of amp hour recharge rate. I can guess the following scenario: Discharge AGM to 50% capacity. Turn off all loads then recharge at 5% amp hour capacity all day every day until charge amperage droops to point five percent amperage rating one half amp per 100 amp hours. Battery will lose 40% of it's lifespan, perhaps 25% of it's lifespan when pain-in-the-ass recovery is used. It just isn't worth it. If a 100 amp hours worth of AGM is not recharged at 20% prepare for the consequences. As in every electrochemical action, time and amplitude enters rudely stage left. A fifteen percent recharge rate is not nearly as destructive as a five percent recharge rate. Having the charge cease during no sunlight just makes things worse (if that's possible). The answer is to achieve a minimum amperage into the battery recharge of 20% AND leave the battery at 95% SOC when it's margarita time. Hitting 100% SOC is hard to do, but the top missing 5% is not Armageddon. The 5% should be made up similar to what top charging does for a flooded battery (See! The batteries have something in common).
I wish things were different, but I have to play by "their" rules, as well.
I wish John Marles (Megawatt) could come up with a large charger that could be tweaked to 14.4 volts.
