Couldn't find a previous discussion on this: Are there any known issues with relocating the battery to the trunk? I'm looking at the filler neck over the gas tank and wondering about safety. I have a black box enclosure with lid & straps, was thinking of running vent tubes from the battery box lid to suck out any possible acid fumes. Anybody got any idears? My car currently has no battery, no battery tray (rusted so bad it just plain disappeared), no gas tank, and frankly no rear quarters (more rust) so there's obviously LOTS of ventilation back there at the moment... Whiskeee
A sealed battery is the way to go for sure. I ran one in another car for many years and it was not vented. Most battery relocation kits come with all you need otherwise. One thing to be sure of is making sure the long cable is well protected from being nicked or gouged as you run it through the firewall etc. I saw a car burn to the ground once that had the battery cable rubbing on metal. Summit racing sells some cool bulkheads for that application.
For best weight distribution, they recommend putting it on the passenger side of the trunk. I took a new coated metal battery tray, the large universal type... and bolted it down to the frame rail on that side. I learned two things from my mistakes... 1: I was using a stock alternator and a 5" Moroso pulley... It worked great until I relocated the battery. When the engine was warm, the extra ohms of all that cable made the starter spin very slowly. Putting a stock pulley back on helped a great deal. 2: I ran a very short ground cable to the frame rail right next to the battery and left the starter solenoid in the engine bay. I should have either ran a ground cable all the way up front, or moved the solenoid to the trunk. The solenoid in the trunk is probably the better idea. But I think this would have solved any starter drag issue by itself. It just seemed like I was always chasing bad grounds and having a hot solenoid. Eventually I got a black plastic box, ventilated marine type, and modded it to fit into the universal tray. The metal brackets held the battery down inside the bottom of the box, then the lid snapped on top. Anyway, my experience... Make plenty of good grounds, move the solenoid onto the frame rail next to the battery, use a large positive cable... Oh, and if you slide the cable over the top of the wheel well from the trunk, and finagle it just so, it will slide out through the gap at the rear of the door, under the sill plate. Then, IIRC, it can go out the front of the sill and re-emerge in front of the kick panel at the firewall. You MUST put a rubber grommet in the firewall, or anywhere else the cable passes through a drilled hole in sheet metal. Otherwise it can rub the insulation off and cause a fire.
Even if you mount your solenoid in the trunk, you still will have to run a heavy gauge wire for the starter. The plus side is the wire is not always "hot". I mounted my battery in the trunk and ran both hot and ground cables to the front. I used 2ga wire and have never had an electrical issues or problems with hard starts. I ran my cables through the rocker panel so the cable is fully protected. I bought my cable at Jamestown Distributors. It was the cheapest place I could find at the time. http://www.jamestowndistributors.co...e=adwords!6456&keyword=jamestown_distributors I also used a sealed battery so no need to worry about venting. I used an Optima. I can highly recommend them.
a friends car had his regular type bat in the trunk. in less that a year cancer was really bad in the rear quarter pannel that the bat was next to. that bat was on one of those black marine boxes. those boxes are not leagle for use on a nhra drag strip. nhra requires a sealed type box that is vented to the atmospher. i have always ran optima bats. in the trunk of several cars, some not in a vented box and never had any signs of rust. also nhra requires a bat shut off switch in the rear of the vehical if the bat is located in the trunk. the switch must shut off the motor when switched. that means you also have to run a new power wire from the alt back to the bat before the switch. if your not concerned about being nhra track leagel then just get sealed type bat. like a optima and put a hold down tray on the trunk floor and you will be fine.
Last time I checked, you only have to vent a battery if it is exposed to the passenger compartment... Like in a Hatchback vehicle or such, without a separate trunk compartment. Also, have a battery that was mounted boxless for a while, then in a black box, for many, many, years... and no rust issues. Not saying that a sealed battery isn't better, but there seems to be a bit of overblown fear of regular batteries in this discussion.
very good....I forgot that and the first time I went through TECH after putting an ALT on my car I got busted.....but I was glad they did
Thanks guys!... Awesome replies... thanks much. I think almost *ALL* new batteries are sealed now anyhow... none of my newer vehicles ever had rust - much less corrosion - anywhere around the battery including the hood above it. I guess these old cars all suffered with acid and gas spray for decades before the newer stuff came out. Every car I've had from 1969-1972 had major rust issues around the battery. I was warned that venting is necessary in a hatchback (my last car was a Honda). I know race cars might need a fuel and batt. cutoff as well as a fuel cell... but I wondered if the filler neck and a vented gas cap would leave any gas fumes in the trunk area. I guess it's not an issue if you've all had success. I'll put it rear-right to offset ME instead of having a spare tire there. Since you've all tried and learned and seem to have done it right... I guess I'm ready to give it a shot. I just REALLY REALLY want to get my new beater running.... Dying to see how the V-8 runs before I start the tear down.
I run 2 batteries in the trunk with no problems. I just put 2 battery trays side by side and run the cables to each of them. Guess I really need to offset the weight of the driver.
