Thanks jrnymn7. I guess I keep thinking of the Morningstar's voltage sense readings as equivalent to multimeter readings across the posts since that's what they are designed to be. Trust but verify, sure, but since the battery compartment is currently snow covered and accessing the controller voltage readings requires hooking the laptop up to it, I'm waiting until spring... It is just these few months out of the year where daylight is at its shortest, along with snow cover, where I think my batteries may be vulnerable. But I check in often enough to not let them get below the low 12's. I also pulled the 12V fuse for the radio and propane detector, so I hope that knocks down my phantom loads to near nothing.
We had snow in the days leading up to Thanksgiving, then had unseasonably warm and sunny weather on Thanksgiving day. So that morning I brushed the snow off the panels and they basked in unobstructed bluebird sunshine all day (although at a very low angle!). After a period of absorption charging the controller went into my 14.9V cycle which with temp correction was at 15.3V. I didn't check in much more during sunlight hours but the batteries were at 12.9 V when I checked back in well after dark. We've since had several more inches of snow but even the blanketed panels had the battery voltage in the mid 13's when I checked.
