Trunk Mounted Battery

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DieselDan

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I searched on this topic and frankly I am suprised there isnt much other information on relocated batteries. Has anyone here done it? I had been tossing the idea of putting 2 studs near the stock battery location and hooking the factory cables to it, and the cables from the rear attached to those. I figured a sealed batt box with a vent thru the trunk floor and use 2ga wire for the pos and negative cables and route them under the car. Also put a circuit breaker in the trunk in the event of a short. Thoughts?
 
Why bother? These cars are not road racers or drag cars. You lose alota power over the lenght of cable. And if you ever bring it to race 1/4 mile you will need an external cut off switch. Would be less hassle to get a light weight battery in stock spot. My old 1000CCA race battery was only 22 lbs. But to each is own. And not a crazy bad thing to do. Both my mustangs have then in rear. Plus the weight of the box and the new long cables adds up trust me copper cable not light. So you add more weight to car total.
 
I had mine in the trunk. Used 4 awg wire. Too thin, but worked. It was already there from the sound system. In my case I had to move it because of the new engine.

Anyway. Just get some L metal channel and cut pieces into a frame to fit the base. You can weld if you want. Or you can rivet it as I did. A simple carpet box to fit around it worked well. In my case the location was that of the defective CD changer. But it was a little tricky getting to the suspension switch since the door swung out and hit the bat a little.
 
GMAN said:
There is absolutely no evidence of power loss because of a battery relocation.
Click to expand...

Yeah i want to know how im losing power when in my LS with my system pounding hard i can still maintain the voltage at 14v.
 
DC current drops as you increase the length of a cable.

Look into DC current amplifiers/repeaters and you will understand that DC amperage falls proportionally to the length and gauge of the wire it's going through.

This is one of the reasons Nicolai Tesla's AC current standard won over Edison's DC current for long distance transmission.

Will DC current drop significantly over a 20 foot 12 gauge wire? No. But it will drop a little.

Read. Comprehend. Retain.
 
Frogman said:
DC current drops as you increase the length of a cable.

Look into DC current amplifiers/repeaters and you will understand that DC amperage falls proportionally to the length and gauge of the wire it's going through.

This is one of the reasons Nicolai Tesla's AC current standard won over Edison's DC current for long distance transmission.

Will DC current drop significantly over a 20 foot 12 gauge wire? No. But it will drop a little.

Read. Comprehend. Retain.
Click to expand...

100% correct If you guys don't know this I really don't know what to say. WOW
 
I understand that post but like i said whatever loss is minimal because even with all
the electronics going i can maintain 13v-14v and the battery is in the trunk.
 
No one is arguing trunk mounted batteries are uncommon. Hell, the LS has a trunk mounted battery, IIRC.

What I'm arguing is that indeed, there is a power loss due to a trunk battery relocation. More-so a relocation in a vehicle that has an electrical system designed for a front mounted battery. Is this power loss great? No. But it is there. Simple as that.
 
Where in my post did you read that i said it was bad or not possible to mount battery in trunk? I have 2 cars with battery in trunk but they are more of race cars. With external cut offs. I know there are plenty of cars with batteries out back LS's,colbalts,bonnies under seat. The ? here is why in a 4000 pound mk8? Are you gonna improve your lap time at limerock or pull a better 60ft at dragstrip with your mk8? Just wondering.
 
Maybe he wants to keep the battery cleaner? i dunno...
 
The biggest draw on the battery is the cranking of the engine. That takes the most power draw. Once car is running and alt is good you will always see the correct 14.5 V at rear battery. Thats why I would only rec 2 gauge wire 4 gauge is cutting it close. Now take 16-20 feet of 2 gauge wire and weigh that with box and you just added weight to car.
 
I am most likely not going to be doing this, I was just curious. I know when I had my SHO, this was as common for them as suspension topics are for us.
 
What gen SHO? Man I hear nothing but bad things about cam gears in gen2's stripping on cams big time.
 
BTW if you did plan to do this you would only need to run the pos cable and ground the battery in the trunk.
 
I had a gen 2, the gen 3s were the one with common cam failure problems. They are also fwd, so prob more use for less weight up front.
 
My brother Barry at BARRY'S PERFORMANCE is mounting my battery in the trunk of mine as we speak. I''ll let you know how it went soon.
 
I'm probably going to have to mount the coolant reservoir for the air/water IC there... But if you don't need that space for something else, frankly, don't bother.
 
Frogman said:
DC current drops as you increase the length of a cable.

Look into DC current amplifiers/repeaters and you will understand that DC amperage falls proportionally to the length and gauge of the wire it's going through.

This is one of the reasons Nicolai Tesla's AC current standard won over Edison's DC current for long distance transmission.

Will DC current drop significantly over a 20 foot 12 gauge wire? No. But it will drop a little.

Read. Comprehend. Retain.
Click to expand...

Strictly due to the resistance of said wire for a given voltage. Reduce the resistance by increasing the gauge, increase the current. Problem with Edison's DC system was the gauge of the cable needed over long runs. Not so much a problem in the short lengths needed for a car.

Tho I agree, unless this is a drag car/auto x, etc, it is a waste of time.

What most people don't know is most of their home appliances run on DC... :)
 
Rear Battery Location

I installed two optima batterys in the trunk. I used 1/0 guage cables. Grounded the setup at the lower body stiffner. I did this because I did not want the lights dimming with the stereo. Was not really concerned with the weight gain.
 
Don Pfau said:
My brother Barry at BARRY'S PERFORMANCE is mounting my battery in the trunk of mine as we speak. I''ll let you know how it went soon.
Click to expand...

Are you having an external cut off switch added to car? If your going to race at any 1/8 or 1/4 mile track this will be needed.
 
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