If I would leave parking light on, shut down the engine and exit from the passenger door, will parking light be on or off? This question is important for me because today I cannot turn the engine on and probably my 12V battery died.
And if the answer to the above question is 'yes', what should I try to use a portable starter or do I need to buy a new battery?
Try to recharge the old battery and see if it can hold a charge and you should be good after that. Used the key to get in car and pop open the front hood. Then connect the power 12 volt jumper cables to the charging port in the engine bay. The car should power up to let you open the trunk. If the battery died overnight and can you jump start the Prius front the engine bay terminals. This can allow you to drive car and start the ICE engine to charge the 12 volt battery. You should drive the car for at least 30 mins to charge up the 12 volt battery. Once you shut the car off and the starts up again. I would say the battery is charging and I would drive the car on the highway for 45 mins to fully charge the 12 volt battery. SM-J737T1 ?
30 mins and/or 45 mins would be nowhere enough time to charge up the 12 V from flat. Think more like 16 to 20 hours. Of course, you don't need to drive the car all this time – it just needs to be in READY. A better idea would be to use a battery charger rather than try and use the car to charge it up.
Others have addressed the battery part of the question............so now let's talk about the parking lights. WHY do you ask that part of the question ? If you intend to leave the parking lights ON for 8 hours or more, a flat battery probably should be expected. Then....I doubt that any special procedure is needed to leave them on, given what they are designed for.
Because I've left parking lights ON, shut down the engine and exited from the passenger door. I'm trying to figure out it caused the dead battery or not.
Well.....it depends on how LONG it sat like that. But the general answer is YES leaving the parking lights ON will run down the battery. It isn't very big. I'm trying to find out why you would DO that.