Regarding stop start
A friend had a Civic and his stop start was random. He also had his battery checked on numerous occasions and proved to be OK.
What he found, purely by accident, was that if he started the car in a quick rotation of the key, 1, 2, starter, it would more than likely fail. If he turned the key to position 2 for a few seconds before firing the starter it worked far more than it didn't
What he thought was that when the 'whatever' was deciding on how healthy the battery was, when the starter motor was firing it was telling the 'whatever' that the battery had insufficient oomph. But allowing the 'whatever' to assess a battery not under strain often worked
Hope that makes sense