James1549 et al, in no way have I dismissed your learned advice. On the contrary, I have focussed purely on the battery being the issue. I have been slow to proceed as you all suggest only because I've been trying to get more info. I'm not a motor engineer but my adult working life has been all about problem analysis and solutions. All my previous cars have been obvious when the battery has started to go, it struggles to turn the engine over and then fails. What is new to me and something I hadn't taken from your posts was the "early" in early warning system. I'm now assuming this means that the battery is still ok but not for much longer. Anyhow, thank you all, new battery is ordered. I'll make one final post (hopefully) on this matter in the new year to confirm the problem has gone.