Group 27 AGM mid life performance report
My 90AH Northstar AGM battery is now 38 months old, and has accumulated ~465 deep cycles. When I cycle it, generally I consume 35 to 65AH nightly, average about low 40's Since June of 2015 it ...
Forum Discussion
Thanks for adding some more data.
I have lowered my total capacity in my monitor to 80AH, from 90, but I really do not much use the % remaining screen, ever on my Blue sky IPN pro remote, I always use the AH from full screen, and sometimes it stays at 0 from full when it will actually 5 to 8Ah from full.
Always a pet peeve of mine with this battery monitor, but this only occurs when I use plug in chargng sources and float it while the battery is still taking 0.2 amps but displaying 100% and 0 from full. it was worse with the screwy 31 as that battery would never taper to zero amps, even at 13.1v.
I tend to rezero my monitor often and try to make it so the solar holds absorption voltage until amps taper to 0.3, as that is when it determines full.
Not perfect monitoring by any means, but miles ahead of just a voltmeter.
This is why I said I started charging at ~60Ah from full as I believe It was down 3AH or so when the monitor started counting the AH from full. The Monitor ticked over from 56 from full to 57 from full right before I applied the Schumachers 25 amps
The 80Ah is a guess as it simply cannot be 90AH anymore with this many deep cycles accumulated. I can only choose to 10Ah increments.
I do not ever recharge via generator or am restricted by generator hours, so 50 to 90 time is not really a concern of mine, but to 100% is, as I do not want it to take 8 hours for amps to taper to 0.45 at absorption voltage.
I am doing the high amp thing on this battery as it seems to wake the thing back up, and I know it does not hurt it. I am also not afraid to dip below 50% when I know I can apply high amperage as soon as I take it as low as it gets.
My later afternoon light discharge cycling, will be met with 14.4 to 14.7 volts until amps taper to less than 0.45 from now on.
I think just plugging in the meanwell set at 13.7ish volts when 5 to 10AH from full was a contributor to my lazy battery symptoms, So now every time, When i plug in, I will force 14.7v until amps taper to 0.45 or less, then drop to 13.6v. Temperature compensated of course.
One thing i noticed when this battery was new, is I could not get it to achieve a full charge resting voltage of 13.0+, as northstar outlines, until I did a ~50% depletion and a high amp recharge on it.
I have lowered my total capacity in my monitor to 80AH, from 90, but I really do not much use the % remaining screen, ever on my Blue sky IPN pro remote, I always use the AH from full screen, and sometimes it stays at 0 from full when it will actually 5 to 8Ah from full.
Always a pet peeve of mine with this battery monitor, but this only occurs when I use plug in chargng sources and float it while the battery is still taking 0.2 amps but displaying 100% and 0 from full. it was worse with the screwy 31 as that battery would never taper to zero amps, even at 13.1v.
I tend to rezero my monitor often and try to make it so the solar holds absorption voltage until amps taper to 0.3, as that is when it determines full.
Not perfect monitoring by any means, but miles ahead of just a voltmeter.
This is why I said I started charging at ~60Ah from full as I believe It was down 3AH or so when the monitor started counting the AH from full. The Monitor ticked over from 56 from full to 57 from full right before I applied the Schumachers 25 amps
The 80Ah is a guess as it simply cannot be 90AH anymore with this many deep cycles accumulated. I can only choose to 10Ah increments.
I do not ever recharge via generator or am restricted by generator hours, so 50 to 90 time is not really a concern of mine, but to 100% is, as I do not want it to take 8 hours for amps to taper to 0.45 at absorption voltage.
I am doing the high amp thing on this battery as it seems to wake the thing back up, and I know it does not hurt it. I am also not afraid to dip below 50% when I know I can apply high amperage as soon as I take it as low as it gets.
My later afternoon light discharge cycling, will be met with 14.4 to 14.7 volts until amps taper to less than 0.45 from now on.
I think just plugging in the meanwell set at 13.7ish volts when 5 to 10AH from full was a contributor to my lazy battery symptoms, So now every time, When i plug in, I will force 14.7v until amps taper to 0.45 or less, then drop to 13.6v. Temperature compensated of course.
One thing i noticed when this battery was new, is I could not get it to achieve a full charge resting voltage of 13.0+, as northstar outlines, until I did a ~50% depletion and a high amp recharge on it.
