I think time has come to design a self-sufficient power system for laptop, phone, and other electronics in my car.
This morning the car wouldn't start. I did use quite a bit of battery power for laptop yesterday night at a fishing pier, but I drove after that too; that is, battery had some charge after. So it's strange that it was dead. I called Subaru Roadside Assistance and in about 30 min help arrived.
Will need to monitor this now, if battery is too weak, I might as well buy a new one.