I have a Victron SmartShunt I use with 2 100AHr Lithium batteries. I've gone through the manual and configured it and have used it for a few weeks. It seems to work, more or less. But sometimes I don't believe what it is telling me. See below for today's charge history. It had dropped to 50% over a few cloudy days, and was charging up this morning. Then around noon, it shot up to 100% in a few minutes. Any idea what could be going on here?