This morning the Defender was a no-start (flat battery?). I didn't have time to look closely so checked it out when I got home.
What I found was amazing. The positive battery clamp had a lot of corrosion on it (haven't checked them for a while obviously). But the bolt through the clamp had apparently broken because the whole thing was loose. When I pulled the bolt out, I found it had melted when it tried to conduct the sort of current required for cold-cranking.
It's something that I will be checking a lot more often!
Regards Scott Forbes