lowlyfe
+1y
Welding wire is just as good with a lower price tag. The only downside is that it's not as flexible.
As far as him reccomending a capacitor, skip that and just run a 2nd battery. Do some research on a car audio forum about a 2nd batt vs. a cap and you will see why.
If you decide to run a 2nd batt, make sure its the same type as your underhood batt ( Wet cell, gel cell or AGM) since you cannot mix them. The batteries should be close to the same age and topped off with a full charge before installing it. You can run the 2nd batt in the rear by running a paralell set of power and ground cables from the main battery.
I've got 2 XS Power AGM batteries in my project ran this way and i've got plenty of power for the system.