In AZ the auto start/stop rarely works in summer because of the temps (learned of 140 degree battery temperature from Haz's post) and load demand, so I didn't notice that it wasn't working. As temps cooled (temporarily) and I was running with the windows down in the AM, I finally noticed it wasn't working. Batteries die fast here. You can park the car in the evening and the next morning, the battery is dead as a door nail and unable to take a charge. I decided I needed to be better prepared. I broke down and replaced my 'suck up battery fluid' tester with a decent digital battery tester. It read 60% SOC, Battery Good-Recharge, so I replaced the Craftsman charger I bought in high school 50 years ago with a new microprocessor controlled charger compatible with AWG batteries. I watched a video on charging and learned that if you want the vehicle to immediately recognize the change, don't attach the charger to the post, but connect it past the electronic sensor that sends battery info, on the negative terminal it's the bolt that sticks upward. I had to move the battery forward to get a good grip. It only charged to 80%, but I remember reading some where that that's the max it will charge, but don't remember why. Long story long, it's now working good, even a couple of times with the A/C on.