There should be a little 1 amp resistor that you use to charge it, then you hook up the power to it. If you don't have the resistor, radio shack sells them 3 for a buck or something. Then use a voltmeter and charge it until it reads 12 volts. Check out the 3rd image down in the link for better instructions. http://www.caraudiohelp.com/car_audio_capacitor_installation/car_audio_capacitor_installation.htm
DONT just hook it up to your battery!