disconnect switch amp rating
A battery kill switch should be rated for an intermittent load (i.e. starting) that is far higher current than their continuous duty current rating. For instance the [ame="http://www.amazon.com/Cole-Hersee-7590401-Master-Disconnect/dp/B001FQNI20/ref=sr_1_1?s=automotive&ie=UTF8&qid=1398005561&sr=1-1&keywords=Cole-Hersee+75904"]Cole-Hersee 75904[/ame] is rated for 125A continuous and 1000A intermittent ([ame]http://www.colehersee.com/home/item/cat/209/75904/[/ame]). If the switch that you're considering doesn't list the intermittent load rating I'd look for a different switch. The 75904 switch also has silver laminated contacts which are far less likely to 'spot-weld' together and not release when they need to.