like rebel said, as long as you have the proper charging system for it. and the small audio battery is about 2-2.5in wide and 5in tall. so it fits behind the seat and its a battery that fuels the amp and sub so not all the strain is comin from your main battery thats supplying everything else. and ground it out back there too, more and better the ground the better itll be, from what im told

 

Good ground is essential, if you don't have a solid ground you'll be chasing all sorts of small issues. After some of the nightmares I had tracking down "noise" with the system in my Integra ground is the first thing I check now (ground loops will drive you nuts).