Ok, after letting it sit for a few hours, heres the measurements...my battery is over 1 year old. 12.37v 12.6v right after shutdown 14.3v idle charge 14.27v with system on at moderate/low volume Actually i listen to it at at volume 30-33 out of 100..i'd say moderate for about 10-12 minutes, the time it takes me to get to and from work. Any other time i drive, usually my wife is with me and i'm forced to keep it no higher than maybe 20.......either way, its usually quick drives, rarely full blast but sometimes i do. Overall, with both my amps, i'd say atm i'm around 1400 actual watts, 1200 if i just use 1 sub. Soooo, no doubt i know i could stand a larger altenator. But my car always starts up just fine, i also listen to my music at low volume on battery alone when i arrive at work in the morning for at least 10-20 minutes....so that may have something to do with my decreased in voltage too, i dunno. but really, i rarely crank it. So not sure where this leaves me other than maybe get a new battery and keep the bass toned down. If its not full blast, i'm not really sucking down all that wattage am i? I guess its a matter of how many amps my stuff is drawing, i don't think i have an amperage setting on my MM but i never blew that 100 amp fuse i have powering it all either.