How do you relocate car battery in a 00 mercury cougar?

Answer 1

You'll need a battery box, RV supplies are readily available and some 4guage red cable - 10-12ft should do it. Look for ways to run the cable through the firewall down the edge under the carpet on the passenger side (original battery location correct?) Make sure that when you punch a hole in the firewall that nothing is in the way behind it! Where the wire will pass through the sheet metal insulate with a grommet to prevent shorting it out. Best to take out the backseat and go through that area into trunk.

Its simple to run a new positive cable to the trunk area where your relocating it to. The negative can be bolted to the frame, choose a clean area and bolt it down real good.