Stop Start working intermittently

[rnamman]

This is all a bit strange, if the bsi is monitoring battery voltage and selectively switches off s/s then maybe the battery capacity is not high enough to cope with short journeys or cold weather and dark nights, when the car has high electrical demands.

Generally speaking the French have further to travel between towns and perhaps this has led to a lesser capacity battery specified than needed in the UK.

Battery capacity drops something like 5% for every 10°C drop, so you can see why some vehicle manufacturers specify a higher capacity battery in colder climates.

Has anyone fitted a larger capacity battery and noticed the problem reduces or is solved. If so what spec was it?

On my 2014 Airdream 1.6 auto the stop/start hasn't worked properly for about two years, but due to Covid I'd only done 400 miles in the last year so the battery wasn't getting much charge. With the wireless, headlights, heater etc on the s/s was always reluctant. Anyway Citroen dealer checked battery at recent service and said it wasn't holding the charge so fitted a new one as per existing. It now works OK and will probably be alright for a few years. My car is always garaged which helps stop it getting extremely cold. I considered getting a bigger capacity battery but never got round to it; maybe the next time I will.