Assuming everything about the vehicle is 100%, if one starts the vehicle at 12Â°F how long does the vehicle need to run for the battery to be back where it was before the start?
maybe a hour or two, depends on a few things,
How low discharged was the battery?
How fast is the engine running (charges slower when idling)
How big is the battery AMP HOUR RESERVE rating.
What amperage the alternator is.