Left the dome light on in 2008 Toyota Highlander for 48 hours. Came back to completely dead battery. Called AAA to come jump the car and the guy said it had been depleted from 12.6 all the way down to 3 volts, and that I should drive it for 45-60 minutes. To be on the safe side I drove it for two hours. After that I left and the car has now been sitting there for 3 days. I’m about to go on a 3 hour road trip, but I read some things stating that the alternator is not designed to recharge a depleted battery and it could damage the alternator. The battery is almost brand new (installed 2 months ago).
Is there any risk of messing up the alternator or should I just go ahead and drive the 3 hours? Will this restore the battery to full charge? Should I postpone the road trip and go to a shop and have them charge up the battery, or is this not necessary?