i have 3 10's, 1800 wat amp, and 2 10" neon bars connected to the amp, and the amps power wire to the battery is 4 gauge. then i have a fuse box on the power wire that uses the big 80a fuse.
What i need to know is what to do to keep battery alive, use the remote starter after i leave it or something? its a 1990 accord stock alternator. does this stuff draw power when the car is off?

 

make sure ur motor is running when ur system is ON

 

You should be fine. 1800 watts isn't too much for a stock alternator to handle. And none of that stuff shouldn't draw any significant current when the car is off.