Yes, this can happen. it was not a "failsafe" in the car. Batteries are physical devices. There was a little bit of charge left, and the ions redistributed themselves evenly during those 30 minutes. That gave you just enough.
I'll bet if the car didn't catch immediately, that would have been it.... all she had left.
1.5 hours gave it a good bulk charge. And if nothing bad happened, there was no harm done worth trying to quantify to the alternator. It probably ran at it's rated output for 5 minutes then backed down as the voltage came within reason.
Counter story - my car has mounting provisions for a larger battery -- for police service and presumably diesel engine. We bought the car with a nearly dead battery, so when I replaced it, I went bigger. I accidentally left the lights on 2 weeks ago when we went out to dinner and game night. Came back a couple of hours later, and they were still on. started up and drove home. (and put on charger). kinda proud of that....
back on topic, chances are no harm done to car. battery will likely have slightly diminished total capacity. charge overnight may help repair it a little. enjoy.
I'll bet if the car didn't catch immediately, that would have been it.... all she had left.
1.5 hours gave it a good bulk charge. And if nothing bad happened, there was no harm done worth trying to quantify to the alternator. It probably ran at it's rated output for 5 minutes then backed down as the voltage came within reason.
Counter story - my car has mounting provisions for a larger battery -- for police service and presumably diesel engine. We bought the car with a nearly dead battery, so when I replaced it, I went bigger. I accidentally left the lights on 2 weeks ago when we went out to dinner and game night. Came back a couple of hours later, and they were still on. started up and drove home. (and put on charger). kinda proud of that....
back on topic, chances are no harm done to car. battery will likely have slightly diminished total capacity. charge overnight may help repair it a little. enjoy.