Circuit breaker for trunk-mounted battery?

[blitzer454]

Don't feel bad, I too drilled a hole in my firewall and had to weld it shut later. Sometimes it just helps to walk away from the project for a day or two, just don't give up. You will get there!

[j.d.roost]

Don't feel bad, I too drilled a hole in my firewall and had to weld it shut later. Sometimes it just helps to walk away from the project for a day or two, just don't give up. You will get there!

Thanks bud.
Solid advice...I guess iracing will get a workout this weekend.

[gator68428]

This is a good thread and has definitely made me think about the safety of my trunk mounted battery in my 68 Firebird.
Today, for reference I pulled apart the trunk liner and back seat of my 2009 Pontiac G8 GXP. It has a trunk mounted battery from the factory.
The live fat battery positive runs all the way through the cabin to the engine compartment.
No remote solenoid or circuit breaker. Adds convenience when jump starting another/the car.
They do take extra care in packaging the wire. So, to each his own and the G8 is a good example of safe trunk mounted battery with great attention paid to wire routing and insulation.

I will not be remote mounting my starter solenoid, nor adding a circuit breaker, in my '68, but I will double check the routing and add more protection to the wire to be extra safe. And i do have a hole in my firewall with the positive prong feeding through as jumper/charger connection point. Done properly its plenty safe.

G8 GXP battery/wire pics (there are fuses on the auxiliary (smaller) wire connections to the battery)







Trunk mounted battery in my 68 Firebird. I dropped it down ~5" to lower the center of mass as far as possible. Makes use of the dead space behind rear wheel-below trunk floor-just inside rear quarter panel.
Added a security kill switch to the negative, but also put a fused, quick disconnect, 16 gauge wire in parallel to ground so my radio and car computer don't lose all power when kill switch is engaged (to open circuit) so I don't lose my radio stations and computer learning. If starter is turned it will instantly blow the fuse, which I've done a time or two already

[blitzer454]

Well at least now you know your fuse was good. You might consider replacing it with a small circuit breaker next time. I like your battery box, that battery is not going anywhere.

[j.d.roost]

Thanks for posting those pics.
Very interesting to see that oem has no fused protection .
Looks like every point where the wire mates to metal has been covered.
Did some digging today and apperently the fox harness needs direct power to the battery on its own fused (separate from the "charge" cable ) line. Found a diagram pretty much evey 5.0 guy uses for rear solenoid mount. Starter,charge,ignition,power distribution center.
Definitely have some thinking to do this week.

[Richard454]

Nice job -Mitch!!! I've made the comment many a time about how the factory does it- but to deaf ears...

The reasoning for the easy jump terminals - and not use the battery terminals are twofold. First it's easier-Second it gets the power where it's needed, to the starter and keeps from surging the electronics which is possible if you use the battery.

Thanks for posting those pics.
Very interesting to see that oem has no fused protection .
Looks like every point where the wire mates to metal has been covered.

Here's my parts car - window sticker of $98K and they don't use protection either-and not trying to save money!! BMW 750IL...and I'm sure that several engineers though it was the best way-







Wire that is used to 'jump' the car-off the BMW-



Used it in my build to simplify jump starting and save the electronics from spikes

[j.d.roost]

So in that big hole I mistakenly made I "think" I got something to work.
Not 100% thrilled about having a stud in the car over a pass through insulated wire...but it looks like I may have just enough clearance.
Heater box bolts in that big hole (inside pic) and unfortunately will be in front of the stud/wire.
Starter sol. is about 6" away from exit point.
Its not all tied down yet bit its pretty much running up and over toe board.
I will add a rubber cover over the studs.

Anyone have experience with the Moroso style pass through connectors?
Worried about the plastic thread stripping or the nut working loose... I assume I could epoxy or panel bond over the threads if I felt it was necessary.


Also I plan on running 400 amps worth of breakers on the + (two 200s).
I know its probably not going to stop wire damage/fire if the **** hits the fan...but I figure its better than nothing.

[gator68428]

Well at least now you know your fuse was good. You might consider replacing it with a small circuit breaker next time. I like your battery box, that battery is not going anywhere.

Ah yes good idea! So maybe there is a good use for a circuit breaker after all.

[gator68428]

Good info Richard! Very true.

I did a similar thing J.d.

Still have to add cover over my stud as well on the inside connections.

[gator68428]

Anyone have experience with the Moroso style pass through connectors?
Worried about the plastic thread stripping or the nut working loose... I assume I could epoxy or panel bond over the threads if I felt it was necessary.

Mine may be a Moroso too but appears to be a slightly different style with a threaded end only on one side and just a jumper prong on the other. What I would recommend for yours is to flip it 180 so the nut is on the inside and the prettier side in the engine compartment, for aesthetics... But if it gets covered up in the end then i suppose it doesn't matter. If covered and not readily accessible from engine compartment then you still may want to look into adding an easy jumper contact point like Richard did. My version does both (pass-through and jumper contact) but it requires me to run starter wire through firewall as well (which i did, carefully with proper boot--lower and more towards the tunnel).

[j.d.roost]

Can you guys recommend a good sheathing for the wire aside from the standard splitloom?
Looking at the techflex mesh stuff...but have no idea if its good for auto.

[Richard454]

Can you guys recommend a good sheathing for the wire aside from the standard splitloom?
Looking at the techflex mesh stuff...but have no idea if its good for auto.

I used several different "things" to 'hide' & protect my wires-

Painless has - Classic and power braid- Also I use a bunch of heat shrink



Here's the wires to the Alternator- left over Russel AN Fuel line covers the small gauge wires


I had some extra 12AN hose laying around-




My fuel injector wiring is covered w/ 1/2 copper pipe - split and painted w/ textured paint-

Covered it w/ cloth braid first-



Then copper pipe-ran it on a table saw- then cleaned it up with a file-





Finished look-

[j.d.roost]

So a bud of mine is an electrician... He saw what I was trying to do and handed me 20 ft of 1/2 non conductive (rubber) flexible conduit.
It is obviously going to put a lump in the carpet..but it will be on the rocker and should not be too noticeable.
I feel like I will have no worries about it chafing or kinking now.

[Yukon Cornelius]

Probably just me, but I still would want a grommet where that wire is running through the metal.

[j.d.roost]

Probably just me, but I stil would want a grommet where that wire is running through the metal.

Yep.
Got one...it's just not installed.
Good looking out.

[jlwdvm]

Your battery is fused at the positive post. Those are fuses on each side. If they blow...no power coming out of the battery. My '13 boss is the same way. I was installing a PCV can in it a couple days before my first track day several years ago, and I accidentally hit the post with my wrench...a few sparks flew. I got back in the car to start it and I had no power to the starter, but some other electrical systems worked. Luckily I had enough time to get a new one shipped in.

This is a good thread and has definitely made me think about the safety of my trunk mounted battery in my 68 Firebird.
Today, for reference I pulled apart the trunk liner and back seat of my 2009 Pontiac G8 GXP. It has a trunk mounted battery from the factory.
The live fat battery positive runs all the way through the cabin to the engine compartment.
No remote solenoid or circuit breaker. Adds convenience when jump starting another/the car.
They do take extra care in packaging the wire. So, to each his own and the G8 is a good example of safe trunk mounted battery with great attention paid to wire routing and insulation.

I will not be remote mounting my starter solenoid, nor adding a circuit breaker, in my '68, but I will double check the routing and add more protection to the wire to be extra safe. And i do have a hole in my firewall with the positive prong feeding through as jumper/charger connection point. Done properly its plenty safe.

G8 GXP battery/wire pics (there are fuses on the auxiliary (smaller) wire connections to the battery)







Trunk mounted battery in my 68 Firebird. I dropped it down ~5" to lower the center of mass as far as possible. Makes use of the dead space behind rear wheel-below trunk floor-just inside rear quarter panel.
Added a security kill switch to the negative, but also put a fused, quick disconnect, 16 gauge wire in parallel to ground so my radio and car computer don't lose all power when kill switch is engaged (to open circuit) so I don't lose my radio stations and computer learning. If starter is turned it will instantly blow the fuse, which I've done a time or two already

[gator68428]

Your battery is fused at the positive post. Those are fuses on each side. If they blow...no power coming out of the battery. My '13 boss is the same way. I was installing a PCV can in it a couple days before my first track day several years ago, and I accidentally hit the post with my wrench...a few sparks flew. I got back in the car to start it and I had no power to the starter, but some other electrical systems worked. Luckily I had enough time to get a new one shipped in.

Right, those are fuses for the small wires connected at the battery. The fat wire is not fused AFAIK--I don't even know what a fuse capable of carrying 500 amps would looks like--if they exist on factory cars I'd be interested in seeing one. If one of those fuses blow the car will not run because the ECU loses power etc. But the fat battery wire remains live all the way to the engine compartment.

[badazz81z28]

Right, those are fuses for the small wires connected at the battery. The fat wire is not fused AFAIK--I don't even know what a fuse capable of carrying 500 amps would looks like--if they exist on factory cars I'd be interested in seeing one. If one of those fuses blow the car will not run because the ECU loses power etc. But the fat battery wire remains live all the way to the engine compartment.

Is that not the main cable on the right side of the fused block??? I have researched those blocks and a lot of them are rated at 175-250 amps

[73ta]

I have a buss fuse rated at 250 amps in the pos cable with a cutoff switch by the battery and have never had it blow starting my 462ci engine. Also run a ton of aftermarket electronics, no issues. Fuse is available at most auto parts stores.

[Warthog5]

Heres a suggestion......STOP using bare copper battery terminals......They are super attractive to corrosion.

Use tinned copper ends.....This is marines grade stuff...Coat it with Diaelectric grease also. I see bare copper ends turned Green or Black from corrosion every day.