battery troubles

ok, I have a coustic 400 watt amp powering my 450 watt bazooka sub, and just recently I've been having problems with the battery, from it being a "hard start" after being at work for 10 hours and just barely turning over, to when I have worked over 12 hours it does'nt want to start. I have been thinking of getting a voltage block that after the battery drains to a certain point it will cut off power till you have to start, but those things are $130 at my local NAPA. I was wondering if a bigger battery ( Optima yellow top) would be the better route, and would running the amp from the second power post on the battery help my headlight dimming problem, or will I still need a capacitor?

Just skip the whole process and buy a decent 1 farad, or 1/2 farad cap for $130.

a cap is gonna do absolutely nothing to help your situation..their a waste of money, only good for barely smoothing out dimming from a stereo system that is too big for a certain alternator...the system you have is fine for your car's alt...something is draining the battery, or the battery is just dead, plain and simple..find out what is draing the batt, pull the fuse for the amp and see if the batt still goes dead...

also, your alt might be dieing..from 400 watts, your car really should not be dimming at all

i was having the same problem until i got a new battery so i would try that. good luck