One positive - gives you more room for A/C compressor. Go with setup by Roger1. Works great! Search it for lots of info.

Fuzz

MAGA

 

Positives are not just more room, but a cleaner looking engine bay. Also a little extra weight off the front, and added over the right rear tire where it helps.
Of course the negatives are you'll need longer, and heavier cables to account for the extra loss through length. And you'll need to vent the battery box unless you buy a sealed battery. And you lose a little trunk space. All things considered I always use a trunk mounted battery.
I had a battery internally short out once, and was really glad it was trunk mounted! It still did a lot of damage, but it was damage in the trunk. If it had shorted out internally and was under the hood the mess to the engine, and engine bay would have been horrible to clean up, and likely meant replacing some nice aluminum and chrome parts!
Imagine this under the hood!

I lost my trunk mat. Had a couple days of neutralizing and stripping metal. Then repainting, and installing a new box and battery. I had just enough slack in my cables to cut off the ends and swage on new ends. So it wasn't a costly repair, and battery company replaced the battery free, but no assistance with cleanup or materials for that.

 

Make sure you route large enough cables for the distance, usually welding cable is a good source of cable to use

 

I like them in stock location, just easier to work on when needed.

 

Here is were I mounted my battery

 

That's a pretty clever use of the spare tire area!

 

The problem with most of the kits is the size of the wire that is supplied with them along with the terminals, etc. Most people will install a brand new battery when doing this project and that in itself can be deceiving. A new battery can overcome some of the extra resistance that the smaller gauge wire will have by the fact that a new battery will and should have more voltage available, at least for the first part of it's life. As the battery ages (and all of them do), the problem becomes double-fold. The battery now has less voltage to overcome the resistance and that wire that was brand new at the time will develop a little bit of extra resistance itself. Then add to that fact that the connections are now not as sanitary and clean as they were when the work was first performed and you have a problem. The best way to overcome this issue is to go a little deep on the wire and terminals to start with - anytime I put a battery in the back of a car I use 2/0, you might get by with 1/0 but the price difference is hardly worth going with the smaller wire. Most of the relocation kits that I have looked at, if they are decent kits at that, will have #2 wire in them. And of course if you simply compare #2 wire to a 2/0 wire the difference is about double in size. The larger wire of course makes resistance almost a non-issue and as the battery ages, it doesn't place that additional load on the battery. Now, you still need to check your connection points on a regular basis but you do the same with your brakes (I hope) so it's not a deal killer. I built my first real bracket car roughly about 35 years ago - a '66 Chevelle SS. The last time I saw the car about 2 seasons ago - it still had the 2/0 cable that I put in it.

 

When I converted the 51 Chevy to a V8 back in 1967, I moved the battery to the trunk. Been there ever since and doing just fine. As every has mentioned, a larger gauge battery cable is needed for the + side. The - side is connected direct to the frame through the trunk floor and then a short cable is connected between a bell housing bolt and the frame up front.

 

The size of a battery cable is important, but the number of strands in the cable is even more important! You can't compare regular insulated wire to extremely fine strand welding, or battery cable as the latter two both have amp ratings that are almost triple standard insulated wire. A 1/0 welding or battery cable is rated 350 amps for up to 50 ft., where a 1/0 insulated copper wire is rated 125 amps. Then there's the flexibility issue that welding and battery cables have over other cable.
I always make up my own, and I use crimp on lugs with ring connectors. I buy batteries with 3/8" bolt on connectors as I prefer them to the usual battery clamp connectors. Once I crimp these on with my Greenlee crimp tool they never fail at the ends, and make a very low resistance connection.
I also use the frame as my ground path and use the same 1/0 cable from battery to frame at the back, and frame to engine block at the front.

 

You're correct, I should have specified that I was talking about 2/0 welding cable. My preference for electrical connections having been in the telephone world forever is soldering. I trim back the insulation on the cable, then fill the copper lug with solder (about 1/2 full) then keeping heat on it, I push the cable into the lug and remove the heat. After a few minutes, it's ready for the heat shrink and I use the type that is for wet locations. It has a sealant inside that seals the entire connection.

 

I've seen guys crimp, and then solder connectors, but just soldering them can be less than perfect. The solder does not conduct current or electricity as well as a crimp, and if the connection gets hot the solder can fail.
I've had twisted, soldered connections that I read with an ohm meter, and they always read higher resistance than the same crimp connection. So if I solder, it's after crimping, not instead of crimping.
In 35 years in the electrical trade I never saw any high amperage connections soldered. All were crimped.

 

So if I solder, it's after crimping, not instead of crimping.
In 35 years in the electrical trade I never saw any high amperage connections soldered. All were crimped.

The smaller stuff I do crimp first then solder, then cover in heat shrink. But I'll give you that a lot of people do not know how to solder correctly and it's a bit of an art. I have also checked my connections in the past for resistance with zero difference. And if a 2/0 cable gets hot enough to melt the solder, we got a much bigger issue going on.

 

Personally I would not relocate a battery to the trunk again in a street car. instead I would use an agm smaller size battery like an xs power d925 or d1200. . Just a lot less work and shorter cables etc.

 

Not much work, or cost to a trunk mounted battery, unless you have to buy a kit, and pay big dollars for it. Buying the cable, a battery box, and a cutoff switch isn't that expensive, if you can make it all up. And I can swap to a trunk mounted battery system in a few hours, even making up all the ends, and adding box, and battery switch. I don't find it tough, or expensive.

 

Correct it really isn't that much work, but I can find a lot better things to do with my time. it also depends on how clean an install you want to.

 

I appreciate the expert information regarding a resistance test procedure. Good info.

 

Vulture the battery cables from an E36 BMW [from your local U-pull] They are the highest quality for trunk mounted battery location.
Mount a Ford starter solenoid in the rear and bridge the solenoid at the starter ,so the main cable is as dead as a dodo unless cranking.
You will need to run another wire to the main harness feed.
This is how I did my race car [there is a Battery Isolator switch between the battery feed and ignition switch for sanctioning rules]

 

I've used my low ohms meter that reads down to .01 ohms.

Yes on the heat and burning. Seen fried connectors literally thousands of times with only a couple that actually went into flames. My brother is an electrician and the one place he worked they had a slogan for the employees, "Loose wires start Fires". A poor connection gets hot, oxidizes, which gives it even more resistance and spirals out of control until it's hot enough to burn (or not crank your engine). I would suggest putting a Mega Fuse at the battery in case your cable ever gets a short along that long run. They make them up to 400 amp, but with today's mini starters, you probably don't need anything that high. In fact if you are using a permanent magnet mini starter, your cables don't have to be nearly as large compared to to an older type starter. You could find an auto store to check your actual current draw while cranking to calculate your cable size from that (and the length of the cable). I believe a typical chevy mini starter only draws about 125 amperes.

 

I personally wouldn't ever want a fusible link of any kind between the battery and the starter motor. Regardless of whether the battery is up front or in the trunk. It will eventually fail, and I wont be left stranded because I added a fuse of any kind between starter and battery.
Fusible links gradually deteriorate from current drawn through them, and will eventually break down. How many 125-250 a. draws they can take is unknown, so it's not like you could replace it after a certain number of cranking starts. I've seen fusible links fail in the field without any excess loads upon them, just from time, and numerous high current draws. So I wont use them myself.
If a fusible link was needed on a battery, the manufacturers would use them, regardless of battery location. A battery disconnect means is a must, and I always put one as close to the battery as possible. Nothing more than that needed, unless you have items that need constant power like an alarm system, or radio constant power. Then a small #16awg. wire fused at a few amps can be attached ahead of the battery disconnect switch to keep them powered when the switch is off.

 

This is where I had mine installed:

Heita! Stay Safe!