Added a battery, interference in speakers
 

So today i added a second battery just for my two amps. I hooked them up and now i am gettimg a whining out of the speakers and a very faint playing of music even though the headunit is on 0 volume.

Is it because the new battery isnt grounded to anything?

I got a perko switch headed in the mail, was just tryin it out today.

Ideas?

Had this happen when I added my 2nd and 3rd. Check all of your grounds. I ended up grounding my head unit to the battery directly and all problems went away.

What for the switch and install the complete battery bank. Once the switch is in and all is wired and configured correctly, the noise will likely be gone.

I concur with Will. Check the grounds, try to make them have the same grounding point if at all possible. Noise in the system like that is almost always a grounding problem.

When hooking up the perko, where does the ground go from the second battery? To the first battery? Grounding post in engine dept?

in my daily experience, unwanted noise in a system with dual battery banks, is rarely a case of where the head-unit is grounded. In reading your opening post, you hooked ONLY the amps to the new battery...............?

All grounds are common between the batteries. And the batteries ground to the engine block with a heavy gauge link from one/either battery, but preferrably the battery used for starting. The Perko switch addition has no bearing on this and has no ground post. Ground ALL audio components to the same point on one battery ONLY, even if connecting through a distribution block. Double check that each and every audio component has a solid ground. You can have a real problem if an audio component is getting a ground from another audio component via the RCA 'above-ground' shield which typically only terminates to a ground at one end of the signal path.

When you get the Perko switch, ALL audio components (source, EQ, amplifiers, ALL) should be connected to the output (C post) of the Perko switch ONLY, even if connected through a distribution block. Your problem will likely go away. It's a problem if you have the source electronics wired to the helm buss or breaker panel which connects to one battery while the amplifiers are connected to the other battery. Correctly wiring the Perko switch automatically eliminates this particular conflict.

Yes. Only the amps.

Ok well i can tell you that my headunit is getting power from the first battery. It gets turned on when i hit my ignition button at the helm. So when the perko gets here and the main power harness will be connected to the perko is should solve the problem?

Problem solved. I grounded the second battery to the "chassis"

Awesome. It always seems to come down to those pesky grounds. Glad you got it fixed.

Ok so i am a bit confused on how to exactly wire my dual battery setup.

My plan was to have both amps wired to battery 2 and have the alt cable and all other accessories wired to the common post on the perko.

So i planned on running the boat on "both" while boarding and driving around. Then i was going to put the switch on "2" while sitting and listening to tunes. If that battery goes low, just switch the perko to 1 and start the boat.

Does this sound right?

Nope. If you are wiring a Perko dual battery switch then the only item that should be wired battery-direct is a [bilge pump/float] switch if applicable to your particular boat.
The alternator/starter feed, helm buss, and all audio equipment including the amplifiers, should be connected to the Perko 'C' post.
The functionality will be the same as you described but by following the correct & intended method you will avoid other conflicts including noise.

Ok that makes sense, thanks David.

Another question, as for a location of the switch... My boat has a battery powered hydraulic lift for the back hatch (97 super sport) and i do not want to put the switch back their in case the battery goes dead and i cannot access the switch.

Is on top of the vdrive access hatch a decent spot for the perko? I dont want to run cables all over the boat just for this switch. Any SAN owners have advice on where to put it?

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