I was thinking about relocating my battery to the trunk and came up with these questions. I've done a search here and have read the How2 at Cheston's site but still haven't determined; does the battery that goes in the trunk have to be a gel type? Meaning, can I put my current battery, that isn't sealed and requires water occasionally, in there? If so, do I have to vent gases? One last thing, at least for now, I'll probably use a 150 amp circuit breaker - is this a proper rating for my fully loaded 95 SE? Thanks for any responses.

 

the battery doesn't have to be a gel cell, but it would help. if you decide to put a normal battery back there, MAKE SURE TO PROPERLY SECURE IT!!! you don't want it sliding around or spilling.

the 150 Amp circuit breaker will be fine. it will be big enough to cover the current draw from the starter, even if you have the lights on. also, the only way it should trip is if you have a direct short. you need to run at least four gauge wire to the back. i'd prob go ahead and run 2 or 0 gauge, but 4 should work.

one more thing, make sure to put your circuit breaker within 18" from the battery.

good luck!!

 

Gel, ie: optima would be safer, because there's no true way to vent conventional lead/acid battery gasses from the trunk compartment (if it's mounted in the open) & anything you carry in the trunk could get contaminated with those gases, not to mention the possibility of them seeping into the passenger compartment, unless. . .

you were to somehow fabricate a "sealed" battery box (maybe starting off with a plastic marine battery box & lid(?)

You could:

1) Create a seal at the lid somehow (using trunk gasket, closed-cell foam tape, silicone, etc). Be creative: lotsa ways to do this, I'm sure.

2) Decide on a mounting location for the box & drill for straps or appropriate mounting hardware. (Careful not to puncture the fuel tank!)

3) If you go to your local hardware store, you should be able to buy rubber grommets in various sizes: choose a size that will fit snugly around the size of battery cable you've chosen. This should be the type of grommet that can be inserted into a drilled hole in the battery box & be held in place by a groove that runs around the outside circumference of the grommet.

4) Drill two holes in the side of the battery box at the appropriate height/location to meet up with each of the battery posts, to accomodate your new (+)&(-) battery cables.

5) Next, pop the two rubber grommets into place in the holes.

6) With the aid of some spray silicone lubricant (preferable to WD-40, but if that's all ya got, go with it), on the new battery cables, pull your new battery cables through the now grommeted holes in the battery box. Next, cut cables to appropriate length.

7) Now, crimp/clamp new post terminals (verify correct size to match your posts, first!) onto the ends of your new cables inside the box.

8) Run a length of automotive standard vacuum hose from the inside of the battery box (through a hole drilled somewhere near the top side of the battery box [again, fitted with anothr rubber grommet]) down and through another hole, which you'll drill in the trunk floor (sealed around with clear silicone, top&bottom) and pointing toward the ground. (Be sure the bottom of the hose protruding through the trunk floor under the car is at least 3" long! (Battery gasses are corrosive & could damage the area around your "vent" if the hose is too short).

9) When you're all done, use some clear silicone adhesive to completely seal up the rubber grommets and leak-proof/protect the sheet metal wherever you did any drilling (both the inside & the underside of the trunk sheet-metal.

10) Make sure the battery doesn't have room to flop around inside the battery box: insert some closed-cell foam panels, cut to fit, or whatever material you choose between the battery sides and the battery box walls to keep it firmly in place. Alternatively, you could use a nylon battery "strap" (it's like a seatbelt) available at marine hardware stores and use fixed mounting points under the battery box or just to the sides to secure it firmly in place. (actually, safer than the box being mounted separately to the trunk floor, having the battery's full weight tossed against the mounting points on the plastic box's floor).

This is a how-to I just imagined in my head - I haven't actually done it, so please don't ask for pictures or part numbers (I don't have them). (If you do this and it takes off, I want in on the patent rights)!


"When all is said and done, more is usually said than done."
-Unknown

Good luck!

 

If you don't want to build a sealed box then JEGS also has some kits for $30-$90. I'd go Optima myself since it will also stand up to heavy vibrations.

Why R you moving it anyway?

 

If you connect the battery in the back, would you run 2 wires to the trunk, a 2 gauge positive and a 2 gauge negative?? Or would you just run one 2 gauge positive, and make a really thick ground connection in the trunk to use as negative??

DW

 

BEJAY1 I am considering moving it for two reasons: 1> I'd like to clean up the engine bay some more and 2> I'd like to possibly make a cold air box. I was thumbing through a Summit Racing catalog and saw a kit they had with all the wiring and everything and it was only like $43.00. It isn't a sealed box so I don't think I can race with it. I am going to the local track tomorrow and will ask if I can get away with it. I may not move the battery but, for $43.00 I'd consider it.
dwapenyi As for the other question about wiring; yes, you would run only the + wire from the engine compartment back. (the kit I'm looking at comes w/ 20' of red 2 guage wire) YOu would then just ground the battery near the trunk. I would drill through the floor and try to attach it to a section of the subframe or something sturdier than just the floor of the trunk.
Thanks everyone for the responses. Keep em comming if there's more to know.

 

Ahhh. Thanks I gather you would use the left side of the trunk, that little pouch area, seeing as the tire jack occupies the right side?

DW

 

What are the benefits of moving the battery? Is it for weight distribution or something?

SuDZ

 

you see in a fwd car it is a funny thing. Yes moving it to the rear will give u better weight distribution, it offsets weight of driver, but less weight on the front wheels = less traction and more wheel spin. It works great for rwd cars since it puts more weight on the rear.

But toolrocks said he just wanted to clean up the engine bay and add a CAI, thats why hes doing it.

 

Yeah thats the part that sounded odd. I was trying to figure out why it would help by taking the weight off but in this situation it does make more sence.

Thanks

SuDZ

 

I know a local member, sinewave, did the battery relocation. He mainly did it because he's an autocrosser. Supposely, it helps.


The Optima is a great battery to go with. However, it is still very heavy. Is there any light weight gel cell battery in the market?

 

Yes, less traction, but better handling because it shifts our car's front bias more towards the middle. Not quite 50/50 weight distribution, but better.

DW

 

Most people doing it for weight re-distribution would mount the battery on the right side of the trunk, since the driver's weight is on the left side of the car: theoretically, you wouldn't want a heavy driver & a heavy battery both on one side of the car (that's the way the setup comes from the factory)

If you mount it in the left side of the trunk, you're really only cleaning up your engine bay & moving weight to the back, not balancing the weight relative to the centerline of the car. It's possible to mount it pretty close to the right side & still retain decent access to the factory jack compartment. See member sinewave's battery relocation project on his website - that's how2doIt!

 

Didn't think about the left to right part. Learned something new

DW

 

Wow, thanks for all the responses guys. I originally thought to do this for cosmetic reasons. I am now thinking the weight transfer will be very nice. While replacing the battery (similar in size and weight to mine) in my girlfriends car I carried hers in my trunk to the parts store. I could really feel a difference. It seemed like familiar bumps were now missing or smoothed out. That was with my battery still up front and hers in my trunk. I can only imagine that the effect would be a little better when I remove the weight from up front and move it to the rear. SO now I am leaning more towards that. My car is slow; I'm not sacrificing too much traction. I'm not sure which side I will put the battery on. I am also going to rebuild my sub enclosure and that goes in the trunk too. I will try to balance all that evenly while maximizing space.n Thanks for the good wishes and hopefully I'll get to do this w/o a problem.

 

I've got my Optima Yellow-Top in the trunk, on the left side. One 2ga. wire (+) runs back to the battery. I have it fused and grounded front and back for safety redundancy, in case of a severe side impact on the driver's side. I don't have it in a box. I do have gold-plated terminal connectors on each wire. The move cleaned-up the engine bay. It made more room for a CAI. It moved some weight to the trunk. (It doesn't counter-act my weight, though. I weigh 270-lbs.) It surprises the h*ll out of everyone who is within sight of my trunk when I open it up...

Everytime I have the oil changed, I hear, "Where's the battery?"

 

[QUOTE]Originally posted by Toolrocks
[B] I am now thinking the weight transfer will be very nice.

Now consider keeping the spare and some additional weight like full fuel and the spare down low back there and you can actually get more than 40% rear weight...

 

[QUOTE]Originally posted by BEJAY1
[B]it seems to me that weight transfer would be a good thing...if you had a rear wheel drive. wouldn't it make more sense (from a drag racing p.o.v.) to have a stiff rear suspension and a softer front so that the rear stays where it's at and the front can raise a bit keeping weight on the front wheels?? -just a little theory i'm working on...

 

Wow this is awesome write up. I never did all of this. I have a marine box in my trunk, but never thought of venting etc. I might change mine to do that.

I used 4 gauge wire, it's quite adequate for our needs. I ran it down the driver's side of the car. I used grommets for going through the firewall. I did not use a circuit breaker. Where can you get these from? I may do mine

 

You can get a circuit breaker from an auto stereo shop or online. I would recommend 150 amp. THis will allow you to start the car even if your headlights are on. I wouldn't go any lower than 100 amp for sure. I still haven't done my battery relocation but saw a Max tonight with it done and it definitely cleans up the engine bay.
Also, I forgot to say but, KWheelzSB that was a great write up. I would say it was sticky material.

 

I hope at least some part of it, if not all, proves beneficial 2 someone! Thanks.


Cheers,
-K-