Inverter Hardwire Problem

Ok, I've taken a regular inverter and tried to hard wire, but I keep blowing fuses. Originally the inverter came with a cig light connecter as well as alligator clip connectors. What I did was clip the alligator clips off and basically trying to hard wire direct to the battery. Every time I do it I blow a fuse. I damn near burned my car up when I tried to avoid fuses altogether by going direct from the battery. Luckily I had the inverter on the ground and the wire wasn't touching much of the car, but the entire covering around the wire burned up. Why is this happening and what can I do to stop it? I have no problems when using the cig lighter connection and had none when the alligator clips were still on. I've discected the cables that I cut and I see nothing that's on them that I should have added so it must be something about the alligator clips that allows for the inverter to draw power safely. Also one last bit of info...the fuses on the inverter are not blowing it's just the fuses within my car. I'm also not using any relays or switches and have not worked with them before. From what I've read a relay may he.p me, but I want to understand how it will help me. 

It blew my 30a ignigtion fusible link.  This was all just in the testing phase just to see if it worked properly which it obviously doesn't.