[airman12]

Hello all. I currently have 2 Apine PDX amps installed into my 2010 Toyota RAV4. One F6 4 ch and a M6 mono amp. I used a Stinger 4000 4 gauge OFC amp kit for the install from the Optima yellow top battery to a 1.5 farad capacitor, the 2 amps are connected to the capacitor. I was thinking of installing a 2nd battery in place of the capacitor with a 250 amp isolator to provide more power when I upgrade my mono amp to a JL audio HD 1200/1. My question is whether it's possible to use the 4 gauge OFC battery cable now in use from my Optima crank battery, thru the firewall to the capacitor to connect to a 2nd battery, probably another optima yellow top. I would install a 2nd fuse near the 2nd battery and the isolator in the engine compartment near the crank battery. I know that's it's probably better to use 1/0 gauge OFC wire but that would mean tearing the 4 gauge wire out and putting the 1/0 gauge wire in while the 4 gauge wire in already there. Would using the 4 gauge wire with a Optima D35 Yellow top as a 2nd battery work or do I have to use 1/O gauge wire?

 

[miniSQ]

you don't need a second battery for the upgrade you are considering.

Add a second run of 4 gauge for the new amp, and ditch the cap. ( you don't need that either ).

 

[Alrojoca]

Correct,
For that system, you don't need 2 batteries. Capacitors are obsolete and just give more issues, making your alternator work harder.

You have new class D amps. effficient amps.

You only need one larger size AGM deep cycle battery, you can make or add spacers to raise it if you go with a size 34 or 36.

Simply add another gauge 4 line of wire, unless you already have 2 direct lines, fuse accordingly and you will be fine. If you have dimming lights or power issues, then you may have to take other steps, until then save the expense