Looking to add a capacitor or upgrade your car battery, but not sure which to get? In this video, Sonic Electronix explains some of the details about adding batteries (such as an XS Power or Kinetik Power Cell) vs adding capacitors.
While upgrading or adding batteries is the best solution, there are many that prefer to install capacitors when they upgrade their car audio system. As a general rule at Sonic Electronix, "When in doubt, choose a battery".
Battery vs. Capacitor Knowledge Base:
Car Batteries (Power Cell): http://www.sonicelectronix.com/cat_i228_car-batteries-and-power-cells.html
Sonic Electronix: http://www.sonicelectronix.com/