Loaded V vs OCV for DOD Lifeline AGMs ?
Anyone explain this please? They have 50% at 12.15v loaded at the 20hr rate, but say it is 12.18v OCV. Shouldn't the loaded voltage be farther down from the OCV than that? (Appendix in link) h...
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My opinion is the 50% 'rule of thumb' can be largely ignored with AGM, especially when one can meet 20% charge rate and preferably more, and then hold absorption voltage until amps taper to 0.5% of capacity.
I'll regularly use 65Ah overnight, of my 90Ah battery and have ~1100 deep cycles and thousands of engine starts and many hundreds of shallow cycles in the 85 to 95% range on it in the last 5.5 years.
I judge battery health by loaded voltage, but I will still see 12.2v+ under a 4.5 amp load at 45Ah from full if it is within a few days of a high amp recharge to full. If it has been two weeks since the high amp recharge, this will be 12.1 or perhaps 12.0 at the same 45Ah from full and I view this as an indication it is time to draw it down deeply and parallel my second 25 amp charger to my 40 amp power supply and blast the mofo with ~65 amps until it reaches 14.7v. which took about 24 minutes when the battery was newer and is about 18 minutes now.
I'd also not be trying to compare lifeline loaded voltage to other AGM's. You have the trimetric, reset it after a 20% charge rate to 0.5% at Vabs, then pull 50% the amp hours out of them at the 20 hr rate.
You can then see where 50% loaded voltage resides on your specific batteries at their specific temperature, and then unloaded voltage, and how quickly it rebounds and use this data as referece for future discharges.
Northstar AGm says 50% is 12.11 volts. I dont believe that at all, as if that were true my 90Ah battery should be rated instead at ~125AH. Obviously it is not, so I put no Stock in 50% rested or loaded voltage charts that populate the web.
The green yellow and red chart voltage/SOC chart posted here ad naseum, is likely one of the most ridiculous things I have seen purveyed on any forum, as people take it as gospel.
My AGm rests fully charged at 13.06v, but that chart says 12.73v is 100%, and people will pull out a voltmeter, see 12.68% and declare 98% charged as if in ultimate authority. Freaking ridiculous.
My AGM at 12.73 rested is nowhere near 100% charged. But that chart says so, so it must be true!!!!!
I'll regularly use 65Ah overnight, of my 90Ah battery and have ~1100 deep cycles and thousands of engine starts and many hundreds of shallow cycles in the 85 to 95% range on it in the last 5.5 years.
I judge battery health by loaded voltage, but I will still see 12.2v+ under a 4.5 amp load at 45Ah from full if it is within a few days of a high amp recharge to full. If it has been two weeks since the high amp recharge, this will be 12.1 or perhaps 12.0 at the same 45Ah from full and I view this as an indication it is time to draw it down deeply and parallel my second 25 amp charger to my 40 amp power supply and blast the mofo with ~65 amps until it reaches 14.7v. which took about 24 minutes when the battery was newer and is about 18 minutes now.
I'd also not be trying to compare lifeline loaded voltage to other AGM's. You have the trimetric, reset it after a 20% charge rate to 0.5% at Vabs, then pull 50% the amp hours out of them at the 20 hr rate.
You can then see where 50% loaded voltage resides on your specific batteries at their specific temperature, and then unloaded voltage, and how quickly it rebounds and use this data as referece for future discharges.
Northstar AGm says 50% is 12.11 volts. I dont believe that at all, as if that were true my 90Ah battery should be rated instead at ~125AH. Obviously it is not, so I put no Stock in 50% rested or loaded voltage charts that populate the web.
The green yellow and red chart voltage/SOC chart posted here ad naseum, is likely one of the most ridiculous things I have seen purveyed on any forum, as people take it as gospel.
My AGm rests fully charged at 13.06v, but that chart says 12.73v is 100%, and people will pull out a voltmeter, see 12.68% and declare 98% charged as if in ultimate authority. Freaking ridiculous.
My AGM at 12.73 rested is nowhere near 100% charged. But that chart says so, so it must be true!!!!!
