As mentioned on this forum previously, I killed the 12v battery about 18 months ago when washing the car and had to be boosted by the AA. Lexus checked the battery and said it was fine. About 6 months after that it failed when loading the car to go on a day trip. Again Lexus said it was fine and wouldn’t replace it. At the time I said to them that the battery often read 10.9 or 11.1 volts across the terminals but they wouldn’t budge.
I have since always put the car in ready mode for any time it is unlocked for loading, cleaning etc.
I bit the bullet and bought a new 12v replacement battery from Lexus at it’s last service because I was suspecting that with my 18day holiday and the car stood out in the cold on my drive, I would return to a dead car. Having a dead car is only a minor inconvenience as I have a Booster, but I am sure the dead battery events cause irreversible damage the cells.
Anyway. 18 days later and it has opened and started perfectly.😬