The service life of the battery could also depend on the Morgan model. I am not familiar with the Plus 4. In my various Roadsters, the battery was drained after three weeks. I sometimes forgot to use the main battery switch and disconnect the battery. As a result, the battery was often deeply discharged and the service life was only one or two years. My 4/4 has had its first battery for 10 years and 120,000 km. So a lot of starts etc. I never use the main battery switch, because in the 4/4 I can start the car after three months and no consumer sucks noticeably on the battery although I also have an immobilizer.
