Building a Badazz Car, need a little impute pz
 

I have a 2005 Scion TC, I have completed the out side with a wide body kit, all carbon fiber, wheels and air bags,two things left one being sound system and one being TurboCharger as the last thing to do. Sound first. Start with under the hood and than to the Woofer box, all is bought and ready to install, for under the hood I am placing Alternator with a high output 180 amp alt plus battery is a Optima 8012-021-FFP YellowTop Group 34 Deep Cycle Battery and replacing all grounds with 0-gauge wire than running 0-gauge wire to the battery Shuriken SK-BT45 12 Volt 1250 Watt High Performance AGM Power Cell Battery in the car under the woofer box with easy access to it. radio is a Alpine IVE-W535HD 6.1" Double Din In-Dash Touchscreen Receiver Car Stereo Radio With Bluetooth RMS 50W X 4 that will run front and side speakers only from the battery under the hood. The Shuriken SK-BT45 12 Volt 1250 Watt High Performance AGM Power Cell Battery will run the woofer box only, from cell will wire it to a Rockford Fosgate 10 Farad Hybrid Digital Capacitor, using Pyramid RPR825 8 Gauge Power Wire to amps, There will be three amps two Alpine PDXM12 1200W Mono RMS Digital Amplifier, each running a Alpine Type-X 12" Subwoofer Max RMS 1000w Peak 3000W plus the Third Amp being a Alpine PDX-F6X4 Channel 150W Car Amplifier running two sets of SPR-60C W/Tweets RMS 110W Peak 330W. On each Amp I will be usiing a RUX-KNOB remote bass control knob. Also changing out rear side speakers with Alpine SPR-50 5.25" Car Audio Coaxial that will be powered from radio not amp set up. The Woofer box is a Box that takes the place of the back seat perfect match but thicker but each woofer will have its own sealed box attached to the outer box. the two sets of 6 1/2 speakers (SPR-60C W/Tweets RMS 110W Peak 330W) will also have sealed boxes other than the tweets.. Two questions! one being after doing alot of reading think that I might need a Isolator between the under the hood battery and the cell that runs the Woofer system so to lesson the draw when engine is not runnning. I am pretty good at building things and wiring , but could use a expert on certain things that I am uncertain about or did not bring up. Any inpute would be great. There are now pictures to check out the ride.

Ditch the capacitor. Use better power wire in the back, not pyramid 8 gauge.

What are the box specs? Try subs pointing up, port back towards the hatch door.

The isolator is usually not used by anyone from what I've seen, as long as you keep the battery technology the same, and relatively similar age and resting voltage. Both your batteries are AGM, and hopefully rest around 12.6-13.1v. I would connect them without any isolator, just a fuse by each battery on either end of the connecting 0 gauge wire. I recommend you run a ground wire between the two batteries as well, not just ground to bare metal, but you might be ok without it.

what type and size fuse will fit 0 gauge wire? And your comment (Ditch the capacitor. Use better power wire in the back, not pyramid 8 gauge.) Why not a good Capacitor for better and constant power with less drain on the batteries? or is it over kill based on what i am putting in?. If not Pyramid 8 gauge wire that connect amps to speakers, what type and size do you recommend? Thanks for comments.

use a ofc 8 gauge for speaker wire

An Isolator is not needed. I would only use 2 of the same kind of battery and would ditch the yellow top.

If you are planning on running the system for any significant periods of time with the engine off, I'd keep the isolator idea on the table and power the whole system from the reserve battery.

well the plan has changed a little, I will be running two 1250 Watt High Performance AGM Power Cell Batteries for the system only. the Yellow cap will run the car only. Plus I will run 0 gauge wire from the Alternator direct to both batteries, this way is does not draw from the yellow cap under the hood. I will have the Rockford Fosgate 10 Farad Hybrid Digital Capacitor attached to the rear batteries as well. For power I thing that's enough. I think 0 gauge wire should work well for grounds as well as power to both all batteries. The grounds are the big thing making sure there is less problems. I will post pictures once done. Thanks for the responses.