Ammo Box for Trunk Mounted Battery...

Not to continue to stir the shit pot, but I remember an article in Hot Rod a few years ago touting the virtues of moving the battery to the trunk on the right side.

My thoughts always ran along the lines of 49ratfinks (does a battery make that much of a difference in a car?) but if you were talking about shaving 10ths of seconds off or something... maybe it would at that.


p.s. My 65 Econoline had a metal box DESIGNED for a battery mounted under the seat with holes drilled and everything. Maybe you could find one of those.

 

I feel dumber for even reading this thread But I will take another toke

 

In my neighborhood, a battery under a non-locking hood, like that of a 60's Pontiac, is a stolen battery.

You can vent the box out the bottom and through the floor.

 

Hydrogen gas in very much quantity is explosive.
Keep that in mind when venting could get a surprise if your a smoker.

 

A few of you are beginning to see the "light", but I'm surprised no one has mentioned using the tried & true "OPTIMUM" sealed aircraft type battery, sold at SEARS along with a plastic MARINE battery holder.
All other conventional vented batteries used in a "AMMO" can or metal holder WILL be subject to CORROSION & spillage!!----Been there done that!
Again like some of you, I have run 00 welding cable from trunk to starter motor & ground to frame, being an old retired welder that was an easy one.
I have been using the Optimum battery with Marine holder since 1995 in the trunk & never had to sweat the vent & spillage problem again!!------Don

 

Even sealed batteries vent.
They are considered sealed because they use a saturated mat or gel type electrolyte.
That means there is very little liquid sulfuric acid in them so even if they crack not much fluid will come out.
Even the optimum battery website talks about using them in a vented area because they have a potential to vent.
If they didn't when they were charging hard the pressure would build up inside.

 

Batteries short out, catch fire, sometimes explode. After considering the safety implications, put the battery where you want, but I personally think mounting the battery a few inches from the gas tank is asking for trouble.

 

Planes crash too, but like battery and gasoline explosions in cars, the instance is pretty rare.

Nothing is safe. Life causes death. Let's not go overboard.

 

Thank you for the opportunity to repeat my firm belief that a novice builder might put the battery on top of the gas tank, thinking it is cool, without considering the serious consequences. It’s a bad idea.

This past weekend, close by, a man was driving his 'rod down the street with a fire in the trunk,. He barely got out with his life, passing drivers doing everything under the sun to get his attention. The fire started in the trunk in the area of the battery box, arching cables??, nobody knows, but it spread to the gas tank and the car was destroyed, long before the fire dept arrived.

 

So that is one example, and as you said, we don't know if it was a battery issue, or not.

The plural of anecdote is not data.

There are 250,844,644 registered motor vehicles on the road in the US. Each year, 3,300 will have a fire that results in injury, 550 of those will have a fire that results in death. Chance of injury: 1 in 76,014. Chance of dying: 1 in 456,081 (NHTSA).

Chance of being struck by lightening: 1 in 500,000.

Shit happens.

 

If the battery is going inside of a steel enclosure, run the wires through grommets or bulkhead connectors.

With any electrical circuit you want to add some type of protection. I've always used ANL fuses on the starter wire with the battery in the rear of the car. Running any wire from the front to the back of the car without putting a protection device on the line right at the power source can be a big problem should the cable get shorted out. You can always say, I'll route it so it won't short but in an accident, this goes right out the window. I've built a few metal battery boxes and have put the ANL fuses and the holders inside the box to where if the cable were to get shorted passing out of the box, the fuse would blow. If the fuse was outside the box the wire between the fuse and the battery post is unprotected. I'd rather replace a 10-15 dollar fuse after repairing a short than having to replace a large 1/0 wire or a vehicle.

If the box is metal and the battery does not fit snugly inside, maybe weld some brackets on the inside to secure the battery down so it's not moving around inside.

On one battery box I built I welded in a 1/2" tube to the box side and had it to where when the box was mounted in the trunk the tube passed through the trunk floor and allowed the fumes to be directed to the outside of the car.

I would also think about putting one of the battery acid mats under the battery and/or paint the inside of the metal box to cut down on any rot issues that may occur.

I prefer running a dedicated ground wire/cable from the battery to the engine block but I have used vehicle frames before or roll cages to do the same thing electrically. Steel will conduct electricity but not as well as copper. Look at some charts on conductivity and steel is not the best choice but it can be used. If you do run a dedicated ground from the battery to the engine block, also add a connection from the engine or the battery negative post to the body of the car so things grounded to the car body work properly.

Like anything else, make solid connections and use the proper sized wire. With only 13 or so volts to start with, a drop of a volt or two can make a difference as to how things work (or don't).

Jim

 

Wrong.

 

Many car manufacturers put the battery in the trunk. Some - like Ferrari - put the battery up front -- but the motor is in the back!! Anyone here questioning the engineering ability of Ferrari?

How far away from 'under the hood' are the batteries in a semi? Or a boat? Or an airplane?

The 'well it's gotta be under the hood cause that's the way it should be and that's all there is to it' comments on this thread are totally unbecoming on a forum that is ALL ABOUT doing things your own way.

 

I looked at the link and I LIKE the ANL holder they show with the rubber boots. It looks like that would work just fine. The ones I get have a clear plastic cover over the studs and fuse and would be less secure compared to the one you linked to. The ones I get with the plastic cover just snaps onto the base plastic.

I have 1/0 wire on my cars starter circuit. Off of the battery I have a 300A anl fuse and then it goes through a 200A/400A peak relay and then up to a stock starter with the solenoid jumpered. I have an 8.5 compression motor and have never blown a fuse.
On another car I installed a 300A fuse again with 1/0 power wire going through a high torque starter cranking over a 632 high compression motor. On this install I did have a fuse blow just once but found out it was from them cranking the motor over and over and over checking the valve lash more than you normally would (it was a high dollar motor and they didn't want to break it right away) and the battery was also not hooked up to a battery charger. The starter kept getting hotter and hotter and the battery voltage lower and lower and they snapped a fuse. It was replaced and I told them to not keep cranking over the motor so damn much and if so put a battery charger on the battery and they never did blow another fuse.
I had another install with a high compression big block and a stock starter and this too had a 300A fuse and 1/0 wire but the guy went cheap and did not have a dedicated ground and the ground he had was through poor metal to metal connections using the roll cage up to the painted motor plate supports, then through the motor plate with it bolts onto the painted motor. He had very slow cranking speed on this setup and did blow a fuse so I took another one over to replace it and then took some regular jumper cables and dug into the roll cage through the paint and then dug through the paint on the block with the other end of the jumper cables and it cranked over just fine. After he added what I told him to, he never blew a fuse again.
So with all that said with a 1/0 wire and proper grounds I would go with a 300A ANL fuse.

One thing I try and do too is leave a little extra wire so that if needed in the heat of a race a fuse does blow and the problem gets corrected and there is not another fuse available is to be able to bypass the fuse by unbolting the one wire from the one end of the holder and attach it to the other stud. During this time the wire past the fuse is not protected but the race could be finished.

Jim

 

Sigh. Again, there is no reason to run a separate ground cable up front. All you are doing is wasting material and adding weight.

Yes, copper has a lower resistivity than steel. But the flaw in this reasoning is the omission of the term 'per unit area'. In other words, a one square inch cross section conductor of copper has lower resistance than the same cross sectional area of steel.

But your frame rails and body and so on have a cross sectional area much larger than the biggest monster copper cable you run.

The key is to have good connections. One or more poor connections will kill you, not the relative resistivity of steel vs. copper.

Running a separate ground cable up front is only for your head.

You do however need to run separate ground straps between the frame and the motor. I have seen motors (on rubber mounts with no ground strap) smoking the throttle linkage, since that was the path to ground (car in question had no ground strap motor to frame).

 

right on

 

Put the battery in the ammo box in the trunk and mount one of those coolers that looks just like a batter under the hood. Everyone will be amazed when you pull a cold beer right out of your battery.

 

I've dropped some serious IQ points after reading this...

I don't see a problem with putting the battery in a vented metal box, or a plastic box, or a cardboard box, or a sub box... I have close to 30 old john deere tractors sitting in the field and everyone of them has a metal box that's not vented that well, some are under the seat, some are right under the gas tank...

In an auto application it wouldn't hurt to put some sort of rubberized coating on the inside of whatever box your using, just to protect it...

As far as location, put it where ever you want... I don't see why it matters to anyone on here if you put it in the trunk, under the seat, or up your ass...

sometimes I wonder why I ever read anything on here...

 

For direct current, it is the circular area of the conductor, stranded or solid.

It's also a good idea to run a ground strap between the body and the frame.

 

not true by any stretch....

 

...and the fact that I am an ASE Certified diesel tech, with factory training...

 

A100 dodges had 'em too (i've got one as a start for my "little red wagon" clone, no i need the rest of the truck )

 

Nice! I like the knife switch. I'm glad you got it done, and put it where you wanted. Do you have a cover for it? I only ask because you will have to pay attention to the exposed knife switch contacts, when loading the trunk.



cool job on a cool car!

-rick