RV Voltages too high while charging
I have a problem and have been wrapping my head around this for a few days. I have four 100w Solar panels, and a Morningstar RJ-45 programmable charge controller wired to batteries. I have Four In...
Forum Discussion
landyacht318 wrote:
A hydrometer will tell you if those 'interstate recommended' voltages are necessary. The deeper the discharge then the more likely it is that they are required. If you are just doing shallow discharges then it is likely that you do not need 15's to return SG to near maximum
Isn't Johnson controls now making Interstate gc-2 batteries?
I thought their recommended voltages were lower, and it was when US battery was making their GC2 that the 15.3v was documented. Can you find a date on that documentation as to interstate recommendations?
I've got a group31 USbattery that requires rather extreme voltages to get the SG into the green daily. Now it has at least one cell which no longer gets above 1.255 no matter what, after about 450 cycles.
I still hammer it overnight, but have reduced my charging voltages to 14.4v and it stays there all afternoon, and the 15.3v I used to let it stay at all afternoon has not been applied for a while now. Kind of just waiting for a cell to short but the thing easily meets my overnight needs so I will keep it under the hammer.
My US Battery docs say 14.7V Absorb for 2-stage charge, and 14.4V absorb and 15.3V "finish" for 3 stage charge.
As my solar charger doesn't provide for a separate "finish" stage, have found that a daily 14.8V Absorb works pretty well. All the way down to 1A charge current or 3hrs, whichever comes first. When in storage with tiny loads, Absorb lasts less than 5 min (the resolution of the log entry). That's with US Battery US2000 GC2s.
