I have a SmartSolar 75/15 and a 200ah LifePO battery. The Victron app shows rapid and large changes in the voltage of the battery. For instance, I checked it an hour ago and it showed 0.0 volts. Now it shows 14.18 volts. The screenshot shows voltages ranging from 0.0 to 14-plus daily. This seems unlikely to be accurate. It has been too cloudy to get any solar power from the 100-watt rooftop panel. But I have it plugged into shore power. Any idea what could be going on? Bad battery? Loose connection somewhere? Thanks!