helotaxi
5,000+ posts
Kilroy was Here
What's you point? That has absolutely nothing to do with the topic at hand.Its ghettoy but it works, with a battery isolator you will achieve isolation between your starting battery and auxiliary battery. When the vehicle is running the battery isolator will charge both batteries as long as there is a load. Under heavy loads, auxilary battery for your car audio, current will go directly to your alternator output. All your doing is using both batteries to run your car and your stereo.
If you play your music with the vehicle off you will drain both batteries, longer run time, but if you install a battery isolator only your aux. bat. will drain and your starting bat. will be fully charged.
Electrically running a wire from the alt to the second battery is no different than going from the alt to the first battery to the second. Using good sized wire the difference in wire length is going to cost you less than 1 ten thousandth of an ohm which is less than a hundredth of a volt with a 100A continuous draw.