Auxillary power system for amps only.

I am trying to devise a plan to use a second alternator and battery in my car to be used solely for my system's amplifiers. My question is... if I share a common chassis ground, will I still experience a drop in voltage? Will It truely remain isolated form the auto's electronics? If not, how can I keep the second power system's ground isolated.

P.S.  Looking for 12 volt wholesalers other than The Wholesale House or Sylvester Electronics.

There is no way to isolate the ground when running two alternators. If you add a second alternator and battery the ground will not cause a drop in the voltage. You might want to check out this link scroll down on the right side and click on the links battery isolators and charging system upgrades https://www.eatel.net/~amptech/elecdisc

While I've seen second alternators put in, I really don't see a point most of the time. The alternator recharges the battery and supplies current while the car is running.
Here's what may be a better solution:

Put in a 200-amp primary high-current alternator.
put in a 1 or 1.5fd capacitor for each amplifier you're installing. Wire them all in parallel after the battery together, so you have a cluster of capacitors from which any amp(s) can draw as a collective reserve if and when needed.
run good power lines, like 1/0 or 4 ga. from alternator, battery(ies), and ground points for both.
run the same back to your amp rack(s)
fuse those links 18 inches from the battery(ies)
put in a strong battery for the main car. Perhaps an Optima deep cycle.
use a battery isolator rig for recharging multiple batteries.
put in more optima deep cycles in the back as dedicated amp-batteries.
fuse each of those batteries too
now go to a power distro block, and drop to 4ga or 8 ga for each amp, fusing those smaller lines through a fuse-block from someone like Stinger or PG or Esoteric Streetwires
ground all amps as close to the individual component as possible, getting a good, heavy chassis ground.
That setup should power anything you can throw at it.


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-GlassWolf
Pioneer Stage-4, Orion, DynAudio, Fi