Just got a Wal-Mart deep 27 with 750cca; more cca than my old one.
I would have to break out the manual, if I could find it, but I think my 1995 oil injected 3 cylinder Merc charges all the time at 2 amp.
My cranking battery used to be the last to get charged; sometimes the day before I go out again. After reading this it will get charged like the others; as soon as possible... Thanks again Terry