I have a boat with a Victron MultiPlus 12-3000 and a BMV-501 battery monitor. When I am moored up on a landline for long enough, the control panel shows 'float' and the monitor 100% charged. When the charge reaches float, the monitor resets automatically. All good. However, the Ah reading then increases from zero to a number that depends on how long I stay on the landline. Over winter it can read hundreds of amp-hours before I reset it. What can a positive Ah reading possibly mean when the batteries are 100% charged? Is this normal? Shouldn't the Ah reading remain on zero when the batteries are fully charged? Before I leave, I reset the monitor each time so that Ah is zero. Not a big deal, but a long-standing mystery.