Woo Hoo..New AGM Batteries
two of the new ones in their workplace, the battery rack last night 7:30pm meter 12.93v lights and fans running this morning 6:30 am (early for us) 12.62v down 65ampHrs from full i set th...
Forum Discussion
My 38 month old Northstar group 27 AGM, with about 450 deep cycles on it, is now starting to show signs of its age and its significant workload in its life.
I bring this up as my indicators are NOT voltage held per AH removed in my regular overnight usage which I monitor closely. I can still pull 45 amp hours from its 90AH total(new) at a rate twice that of what peukert allows, and it still will rebound quickly above 12.2v with most of the loads removed from it. It did so last night with a starting battery temperatuire of 55f and a 1Am battery temperature of 46.5f.
I can tell it is fading because it requires less amperage to reach absorption voltage. When new and depleted it could easily suck up 106 amps from my alternator. Now this is down to about 50 amps before attaining absorption voltage.
I can also tell it is fading as when charging it takes longer for amps to taper to 0.5% of capacity at absorption voltage, and after many partial state of charge cycles, much much longer for that threshold to be reached. I could not do it on Solar alone. I need to plug in for this Vabs duration.
Also when newer it could be held at Vabs until amps tapered to 0.0X amps. The other night I held it at 14.7v overnight and it tapered to only 0.2 then I unplugged and started the next cycle which was last nights impressive voltage held at 50% charged in cool overnight temperatures.
If I were to judge performance simply by voltage held in my overnight usage, I could proudly(yet ignorantly) boast 'just like new' performance, and indeed, voltage held at 50% is impressive, still, and very similar as when new.
Of the ~450 deep cycles accumulated so far in the 38 months, I estimate that about
~65 of those are well below 50% with a few as low as 25%
~250 of them are to nearly exactly 50%
~ 125 of them are to 65%
~40 to the 75% range
Not included in the estimated deep cycles listed above, are shallow cycles which I consider 80% and above, which I estimate to be in the 250 range.
With several thousand engine starts and a few hundred 95% cycles on it too.
Last week I was 58Ah from full, reading 12.08v and used it to start my engine.
Voltage was still well over 10.8v when engine caught, and My montor indicated as high as 147 amps required to turn starter. I find this extremely impressive.
As this is my only battery, for both house and engine, i will be considering soon acquiring and carrying a small emergency 'jumper' battery, as I expect degradation to be faster from here on out with the much extended absorption times required for amps to taper to 0.4 or less at absorption voltage.
I will see if Odyssey's AGM's reconditioning procedure has any effect on absorption duration, at some point but require another battery to switch all loads to. After many PSOC cycles, absorption duration always increased, but after a high amp recharge was back to ~3.5 hours as when new, but the few most recent high amp recharges have not really reduced the time to the same degree and made me come to terms with the middle aged battery.
I do not know how my observations apply to Mr Wiz's telecom AGM batteries, BUt thought I should share my experiences with my hard working thin plate pure lead AGM.
With my previous flooded batteries, granted they were not recharged as precisely, but their voltage held under overnight loads considering Ah removed from them, was obviously decreasing with age and deep cycles accumulated, but my AGM using that same yardstick, is performing just the same as when new.
It is the other yardsticks which reveal the age, amps required to reach absortion voltage when depleted, and the time it takes amps to taper to 0.5% of capacity at absorption voltage.
While I am recharging this AGM better via adjustable voltage manual charging sources, I am also depleting it much further than any flooded battery I have had in the past.
If it failed tomorrow, I'd still get another Northstar AGM, but perhaps a group 31 insted of a group 27.
I bring this up as my indicators are NOT voltage held per AH removed in my regular overnight usage which I monitor closely. I can still pull 45 amp hours from its 90AH total(new) at a rate twice that of what peukert allows, and it still will rebound quickly above 12.2v with most of the loads removed from it. It did so last night with a starting battery temperatuire of 55f and a 1Am battery temperature of 46.5f.
I can tell it is fading because it requires less amperage to reach absorption voltage. When new and depleted it could easily suck up 106 amps from my alternator. Now this is down to about 50 amps before attaining absorption voltage.
I can also tell it is fading as when charging it takes longer for amps to taper to 0.5% of capacity at absorption voltage, and after many partial state of charge cycles, much much longer for that threshold to be reached. I could not do it on Solar alone. I need to plug in for this Vabs duration.
Also when newer it could be held at Vabs until amps tapered to 0.0X amps. The other night I held it at 14.7v overnight and it tapered to only 0.2 then I unplugged and started the next cycle which was last nights impressive voltage held at 50% charged in cool overnight temperatures.
If I were to judge performance simply by voltage held in my overnight usage, I could proudly(yet ignorantly) boast 'just like new' performance, and indeed, voltage held at 50% is impressive, still, and very similar as when new.
Of the ~450 deep cycles accumulated so far in the 38 months, I estimate that about
~65 of those are well below 50% with a few as low as 25%
~250 of them are to nearly exactly 50%
~ 125 of them are to 65%
~40 to the 75% range
Not included in the estimated deep cycles listed above, are shallow cycles which I consider 80% and above, which I estimate to be in the 250 range.
With several thousand engine starts and a few hundred 95% cycles on it too.
Last week I was 58Ah from full, reading 12.08v and used it to start my engine.
Voltage was still well over 10.8v when engine caught, and My montor indicated as high as 147 amps required to turn starter. I find this extremely impressive.
As this is my only battery, for both house and engine, i will be considering soon acquiring and carrying a small emergency 'jumper' battery, as I expect degradation to be faster from here on out with the much extended absorption times required for amps to taper to 0.4 or less at absorption voltage.
I will see if Odyssey's AGM's reconditioning procedure has any effect on absorption duration, at some point but require another battery to switch all loads to. After many PSOC cycles, absorption duration always increased, but after a high amp recharge was back to ~3.5 hours as when new, but the few most recent high amp recharges have not really reduced the time to the same degree and made me come to terms with the middle aged battery.
I do not know how my observations apply to Mr Wiz's telecom AGM batteries, BUt thought I should share my experiences with my hard working thin plate pure lead AGM.
With my previous flooded batteries, granted they were not recharged as precisely, but their voltage held under overnight loads considering Ah removed from them, was obviously decreasing with age and deep cycles accumulated, but my AGM using that same yardstick, is performing just the same as when new.
It is the other yardsticks which reveal the age, amps required to reach absortion voltage when depleted, and the time it takes amps to taper to 0.5% of capacity at absorption voltage.
While I am recharging this AGM better via adjustable voltage manual charging sources, I am also depleting it much further than any flooded battery I have had in the past.
If it failed tomorrow, I'd still get another Northstar AGM, but perhaps a group 31 insted of a group 27.
