We are much the same, 6x110ah Numax batteries which are coming up to four years old. We have most lights on so we can see on an evening, we have a 12v fridge (used to have fridge\freezer), the inverter is on to power a DAB radio for 5 or 6 hours a day and Mrs-M uses her hairdryer daily. As the batteries are inaccessible they are sealed so fit and forget. I have a NASA BM2 which I only use to see what the voltage is and generally on a morning it is 12.6\12.7. The lowest it has ever been is 12.5 when we haven't boated for a day.