Alternator whine after battery relocation
Thread Starter
Senior Member
Joined: May 2002
Posts: 158
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From: Carson, CA
Vehicle: 2007 Tib
Alternator whine after battery relocation
So I finally got around to relocating my battery to the hatch of my car. I had to wait for the new battery box to come in. But now I'm getting a really bad alternator wine when I rev the car. I checked all my connections, especially my ground, and everything is perfect. Its grounded to bare metal, no constrictions at all. Anyone have any ideas? I moved the battery back to the engine bay for the hell of it, and the whine went away. 
Senior Member
Joined: Mar 2009
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From: Red Deer
Vehicle: 2012 mitsubishi eclipse spyder gs, 2001 hyundai tiburon
2 questions, how strong is your battery and what gauge of wire did you use for your relocation?
If the gauge of wire is too restrictive, then your car will run from alternator instead, as it is fooled into thinking that, due to a lower flow of power from the battery, it must be weak and in need of charge.
Further, if the battery was weak, then the flow of power will be lower if it must flow through restrictive power lines.
If the gauge of wire is too restrictive, then your car will run from alternator instead, as it is fooled into thinking that, due to a lower flow of power from the battery, it must be weak and in need of charge.
Further, if the battery was weak, then the flow of power will be lower if it must flow through restrictive power lines.
Super Moderator
Joined: Sep 2001
Posts: 10,795
Likes: 5
From: Pflugerville, TX
Vehicle: 2000 Elantra
Bigass wires to the alternator and the engine block. Big-big, like 4AWG at least, preferably larger. AND run them AWAY from all your audio wiring especially the low-level signal wires.
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Joined: Mar 2009
Posts: 1,922
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From: Halifax N.S. Canada
Vehicle: 2000 tib
Why do people relocate the battery anyways?, whats the benefit?..its a fwd, you want weight over the front tires,not in the trunk?, plus I'm turboed and the battery is not in the way of anything?.. I don't get it?
Thread Starter
Senior Member
Joined: May 2002
Posts: 158
Likes: 0
From: Carson, CA
Vehicle: 2007 Tib
2 questions, how strong is your battery and what gauge of wire did you use for your relocation?
If the gauge of wire is too restrictive, then your car will run from alternator instead, as it is fooled into thinking that, due to a lower flow of power from the battery, it must be weak and in need of charge.
Further, if the battery was weak, then the flow of power will be lower if it must flow through restrictive power lines.
If the gauge of wire is too restrictive, then your car will run from alternator instead, as it is fooled into thinking that, due to a lower flow of power from the battery, it must be weak and in need of charge.
Further, if the battery was weak, then the flow of power will be lower if it must flow through restrictive power lines.
The battery is a Die Hard Gold. Its 5 months old, and the wire I used is 0 gauge.
My stereo RCA cables are ran down the drivers side of the car, the battery negative goes down the center to the engine bay, and battery power goes under the car on the passenger side to the engine bay.
Senior Member
Joined: Jul 2011
Posts: 1,021
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From: Illinois
Vehicle: 2010 Genesis Coupe 2L track
The battery will never be above ~12.3V under load and the engine off. It is only higher if the car is running. Once the car is running then you are using the juice from the alternator.
The battery is only used for starting and when the car is off. If your running vehicle voltage is less that 13.5v or so then the alternator is on the way out. The battery is not providing power if the car is running.
