Absorption Voltage question.
I have 4 Interstate 6v GC2-XHD-UTL house batteries, two series strings in parallel. Setting up the Midnight Solar 200 Classic Light and I think the Absorption rate appears to be on the high side. ...
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The screwy31 is a USbattery.
If it did not get some time( more was better) at 15.3v each solar recharge cycle,applied only after 2.5 hours at 14.9v, it packed up all its toys and went home. SG would max out at 1.225 after a week of deep cycles and Absorption voltage of only 14.7v, and overnight voltage held was abominable for the AH removed.
Granted this was a 12 volt group31 battery, not a 6v GC-2 battery.
Even with the 14.9v for 2.5 hours then afternoon of 15.3v regimen, specific gravity and performance walked downward until the next EQ charge at 16v was performed.
The screwy31 is still alive, powering lights fans and a TV in my workshop, but I estimate its usable total capacity at abou 55AH, originally claimed to be 130. It drops to 12.12v using just 23AH from it at no more than a 1.5 average amp rate.
Probably 550 deep cycles on it now. No shorted cell yet though. Lots of self discharge and it gets recharged by my twitching tweeker of a Schumacher sc2500a on the 12 amp AGM setting, whenever I feel like it.
If it did not get some time( more was better) at 15.3v each solar recharge cycle,applied only after 2.5 hours at 14.9v, it packed up all its toys and went home. SG would max out at 1.225 after a week of deep cycles and Absorption voltage of only 14.7v, and overnight voltage held was abominable for the AH removed.
Granted this was a 12 volt group31 battery, not a 6v GC-2 battery.
Even with the 14.9v for 2.5 hours then afternoon of 15.3v regimen, specific gravity and performance walked downward until the next EQ charge at 16v was performed.
The screwy31 is still alive, powering lights fans and a TV in my workshop, but I estimate its usable total capacity at abou 55AH, originally claimed to be 130. It drops to 12.12v using just 23AH from it at no more than a 1.5 average amp rate.
Probably 550 deep cycles on it now. No shorted cell yet though. Lots of self discharge and it gets recharged by my twitching tweeker of a Schumacher sc2500a on the 12 amp AGM setting, whenever I feel like it.
