Hi everybody.
thankyou for your very helpful advice.
having read it all through, and having another look at my vehicle I feel a bit of a fool. It has the start/stop facility, it appears to be on ( ie led light is off) but to my recollection it has never stopped then restarted. Where i sit when driving I cannot easily see the switch so have never investigated, I just get in and drive, 22000 miles so far!
Derek, thankyou for your very full response, without that I would never have looked for the stop/start switch.
i imagine that may alter the position a bit. I must have a smart alternator although I have no idea what that means.
anyway, I followed Dereks advise, in vehicle with doors closed for 10 minutes, then tested at battery terminals. With multimeter set at 20dc it read 1 so I switched to 200dc and it read 219.
i then checked at jump point, getting 1 again although if I didn’t press contacts too hard getting 14 to 19v depending on pressure I put on probes.
tried starting, no problem. Checking at jump points whist idling = 16 - 18v
Thinking about what has changed, it’s been a lovely sunny day and I wondered if solar panel had had an effect?
I am feeling a bit more comfortable about condition now. I will continue to check voltage every 48 hrs and also, will look into getting battery tested albeit one Fiat professional I spoke to couldn’t fit me in until Feb next year!
If you think I need more, or different action please let me know and apologies that I led you astray about stopstart.
if nothing else I have learnt a lot about my vehicle over the last few days.
peter