Does it use more power to listen to music with the key on Acc than with it Off. (1 Viewer)

[JCruse]

I just finished changing my aftermarket HU from being switched on/off by the ignition to being always on and switched by the HU itself. (Stereo on without the key) Everything else being equal, does it use more juice to have the key in Acc verses full off? And if so, how much do you suppose the difference would be?

I always heard that supplying power to everything in the car at once causes some parasitic losses.

 

[inkpot]

What else has voltage to it when the key is off besides the clock and the CPU ?

 

[ppc]

I would say the difference in current draw is minimal and not worth the risk of forgetting to manually turn off the head unit and killing the battery.