im getting ready to run 2 12" powerful subs/amp, new head unit w/ GPS, and 4 new speakers. i also have 2 kc lights already.

what do you think i will need to do about my battery?

 

The stock batteries are pretty bad. Additional accessories make them die even faster. At some point you'll want to upgrade to a quality battery like an Optima or Odyssey.

With a lot of accessories, or to run them with the motor off, upgrade to duals.

http://benchmark-designs.com/product...ery_system.php

 

What are the specs on the amp? That will be your biggest draw on the battery.