My boat has a Link-10 which was installed by the previous owner. He told me that after winter lay-up the meter would have to be zeroed because it didn’t register the amperage that was put in by the shore power charger while the battery switches were off. Is this normal? I managed to zero the unit last year but have forgot the procedure and haven’t and the manual doesn’t help much. Hayden Watson S/V Papillon 1988 C30 tr/bs Spokane, WA