XS Power SB500-65 12V 4000 Watt 500 Farad Super Capacitor Bank

The XS Power SB500-65 is a 12V super capacitor bank that banks current and hands it back the instant your electrical system needs it. It carries 500 farads of capacitance, a 4,000W max power rating, and a 12.0 to 16.2V operating range in a BCI Group 65 case that drops into a common domestic battery tray.

Used alongside a factory battery in a high-power stereo, the SB500-65 supplies the fast current that amplifiers demand on bass peaks, so voltage stays flat where a battery alone would dip. Used in a starting system, it pushes a surge to the 12V battery during cranking and then refills in only a few seconds, so back-to-back starts are no problem. Cleaner cranking voltage takes load off the battery, starter, relays, and engine control modules over years of service.

Capacitor cells are also far less bothered by temperature than lead acid. In winter they add a burst of current to a slow-cranking AGM battery; in summer heat they keep working without the loss you see from a hot battery. The cell is rated beyond a million cycles, which is why these banks hold up in delivery vans, work trucks, and everyday vehicles for a decade or more.

Cells can be linked together into a larger pack, so one SB500-65 can serve a modest system today and become part of a bigger bank when your build grows. At 11 lb with M6 terminal hardware included, installation is straightforward.