I jumped it then tested the voltage across the battery, 10V. So I guess it is the alternator again rather than a bad battery cell. I wonder if all my electrical problems are peculiar to living here in the south?
Thanks for all the replies. I'm sure I'll be back for further advice in the future. The only car I ever owned with as many problems was a 71 spitfire! Both nice cars to drive, but pains in the ass to keep on the road!