My Screwy 31
First off let me say I am not stressing over this. It's just a battery, it is only money, it is meeting my overnight needs, but it is displaying strange behavior, and I am curious as to why. So th...
Forum Discussion
I've always certainly expected more than 700 cycles, especially since very few of my discharge cycles have been to 50% and I was spending the extra Money on one of the few true deep cycle 12v batteries available.
Not watering those Crowns in time was certainly responsible for their reduced lifespans, but I also feel it was not being able to meet the manufacturer recommended minimum charge current with Solar. For this reason I reduced the "House" battery from 230 A/h to 130 A/h. But now there is no designated 'house' battery as I can easily choose either for that task.
Despite that soothing flashing green light on my controller, my batteries were not getting fully charged.
Also a factor was my Solar float current setting, and my cycling compressor fridge. I thought the solar "float current setting" was adjustable and put it up fairly high, not realizing it was a threshhold. Once the current required in acceptance stage falls below this threshhold, it reverts to Float mode and allows enough current only to hold the battery at that designated voltage.
So when I had it set high, say like 4 amps for 100 A/h of battery, the second it took less that 8.x amps to hold acceptance voltage it reverted to float, despite my setting the acceptance duration for 2 or more hours, often it would stay there for half an hour or less.
When the fridge cycled off, the voltage would skyrocket, the controller would back off the current, and then Float would be prematurely be triggered, and I used to keep float in traditional float ranges, not as a "finishing" charge as I do now.
So one much keep in mind that the solar controllers are not expecting loaded batteries during recharge, and a cycling load just does not allow them to stay in acceptance long enough, and that soothing flashing green light is lying. I wonder how those with non programmable solar controllers fare.
Now I have the float current threshhold set low, and it will stay at acceptance voltages for 2 or more hours. Now it is a matter of figuring out what this Screwy 31 requires, and so far 14.6 absv and 14.8v float have not been cutting it and water usage is barely noticeable since November. So up go the voltages and durations until a week of cycling has the SG still up in the green, rather than in the white or red as has been the case.
Anyway, I'll update this thread every so often. I am not sure how I plan on Cycling these batteries individually. I really have become so accustomed to the merest blip of the starter on the AGM battery, that when the 31 is used as the starting battery I often don't leave the started engaged long enough for the engine to catch.
So I much prefer the AGM battery to start the engine, But I also enjoy seeing higher voltages at various states of discharge when cycling the AGM. So I might already be an AGM convert.
But since the engine will still start, and everything run off my batteries has had no issues on the 31, what is a 1/2 extra second of holding the key in the start position, and what does it really matter if voltage at bedtime or come morning is 12.4 or 12.1v? I'm not powering a coffee pot or Microwave in the morning and the other battery is always near full charge to start the engine.
Me thinks the A/h capacity of this NorthStar 27 AGM at 90A/h is perhaps underrated. After all the AGM weighs 70 LBS, and the flooded 31 rated at 130 A/h weighs about 4 pounds less.
Yet in every way, Disincluding ultimate longevity as this is an unknown, the AGM performs better, if voltage under load is the key judging factor.
But what other ways are there to judge performance?
The AGM might not win the longevity per dollar, but............
Not watering those Crowns in time was certainly responsible for their reduced lifespans, but I also feel it was not being able to meet the manufacturer recommended minimum charge current with Solar. For this reason I reduced the "House" battery from 230 A/h to 130 A/h. But now there is no designated 'house' battery as I can easily choose either for that task.
Despite that soothing flashing green light on my controller, my batteries were not getting fully charged.
Also a factor was my Solar float current setting, and my cycling compressor fridge. I thought the solar "float current setting" was adjustable and put it up fairly high, not realizing it was a threshhold. Once the current required in acceptance stage falls below this threshhold, it reverts to Float mode and allows enough current only to hold the battery at that designated voltage.
So when I had it set high, say like 4 amps for 100 A/h of battery, the second it took less that 8.x amps to hold acceptance voltage it reverted to float, despite my setting the acceptance duration for 2 or more hours, often it would stay there for half an hour or less.
When the fridge cycled off, the voltage would skyrocket, the controller would back off the current, and then Float would be prematurely be triggered, and I used to keep float in traditional float ranges, not as a "finishing" charge as I do now.
So one much keep in mind that the solar controllers are not expecting loaded batteries during recharge, and a cycling load just does not allow them to stay in acceptance long enough, and that soothing flashing green light is lying. I wonder how those with non programmable solar controllers fare.
Now I have the float current threshhold set low, and it will stay at acceptance voltages for 2 or more hours. Now it is a matter of figuring out what this Screwy 31 requires, and so far 14.6 absv and 14.8v float have not been cutting it and water usage is barely noticeable since November. So up go the voltages and durations until a week of cycling has the SG still up in the green, rather than in the white or red as has been the case.
Anyway, I'll update this thread every so often. I am not sure how I plan on Cycling these batteries individually. I really have become so accustomed to the merest blip of the starter on the AGM battery, that when the 31 is used as the starting battery I often don't leave the started engaged long enough for the engine to catch.
So I much prefer the AGM battery to start the engine, But I also enjoy seeing higher voltages at various states of discharge when cycling the AGM. So I might already be an AGM convert.
But since the engine will still start, and everything run off my batteries has had no issues on the 31, what is a 1/2 extra second of holding the key in the start position, and what does it really matter if voltage at bedtime or come morning is 12.4 or 12.1v? I'm not powering a coffee pot or Microwave in the morning and the other battery is always near full charge to start the engine.
Me thinks the A/h capacity of this NorthStar 27 AGM at 90A/h is perhaps underrated. After all the AGM weighs 70 LBS, and the flooded 31 rated at 130 A/h weighs about 4 pounds less.
Yet in every way, Disincluding ultimate longevity as this is an unknown, the AGM performs better, if voltage under load is the key judging factor.
But what other ways are there to judge performance?
The AGM might not win the longevity per dollar, but............
