Connecting A Power Inverter> 04 Malibu

I have an 2004 Chevy Malibu LT V6. I aquired a power inverter with 750W Max power. I currently have it plugged into a cigarette lighter which limits me to about 120. I want to hook it up to the battery and take advantage of the maximum power, consider that's what I paid for.

Is there a way to slip my cable through the firewall to reach the battery without any modifications?

If I have to modify (ie. drill a hole) what are the repercussions of doing so?

Looking forward to your advice.

No repercussions......make the hole big enough, and if you can, get a rubber grommet, to protect the wire from chafing in the hole.....then seal it so no water enters.....make sure you protect the circuit with the proper size fuse....

What would I use for a sealant some household purpose caulk? Also, are you talking about placing a fuse before the power inverter or can we rely on the fuse inside of the unit?

Sure, just secure the line so it is not flopping around......

You want to protect the circuit from harming the battery......install a fuse right off the battery.....