Quote: !!.53v under a 7 amp load would indicate a capacity of approx 30% left.
What voltage did you start at before you applied the load.
I failed to note that figure but the battery had been on a multistage mains charger for 2 days so I assume it was fully charged.
Next year I plan a long cruise of 2 to 3 months so my preference would be to fit a new battery next Spring, I will just have to treat the current one kindly this season.