Does it use more power if you play your audio full blast?
I use an aux cable to connect to my car stereo but the sound is really soft. So I increase the volume all the way and I get a warning about possible hearing problem but I'm not really concerned about that. I'm concerned about battery life.
yes it uses more power but only by a slight ammount compared to softer volume. if you are worried about battery in your car, get a car charger. they are handy