Big 3 (6 really) Wiring Emergency

[Mommy Wagon 10+ year member]

I currently have my vehicle's (Cadillac Escalade) charging system torn apart, and thought I would look to this group before I went ahead and started the rewiring process.

GM offers a dual battery upgrade package that wires the second battery in parallel to this first through the starter = both positives wire to the starter, both negatives wire to the chassis. There is no isolator or relay in the system. The factory type upgrade is standard in police vehicles, emergency vehicles, even some diesel trucks. Terrible sketch below:

The major issue with the GM wiring is it is 8 gauge at best, and will not support itself let alone a secod battery and an upgraded stereo.

Is there any reason why I could wire the system in 0ga. as per the image below utilizing the alternator positive as the common between the batteries and not the GM way?

I don't see an issue, thgough i don't know if an alternator will charge 2 directly wired batteries without complications. Does anyone have extensive DC electrical system experience that could offer information as to if this would or could work without an isolator?

Click to read more...

 

[Falcons 5,000+ posts]

dont remove any wires. just add 0 gauge onto the 8 gauge and youll be fine //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[cx-7heaven 10+ year member]

dont remove any wires. just add 0 gauge onto the 8 gauge and youll be fine //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

This is the easiest way to do it. The alt already is charging two batts, doesn't matter if they are wired directly to it, or the way it is your picture. FWIW, I was running three batts off my stock alt in my truck(130amp) for over a year with no issues.

 

[Mommy Wagon 10+ year member]

Unfortunately, I cannot do that. My preference is to go new, if I'm adding I like consistency and clean looking.

If I'm safe routing direct to the alternator with 2 batteries and no isolator that's probably what I'll do.

cx-7heaven, what kind of truck was yours that was 3 batteries all routed to the alternator? These were direct correct, no isolator?

 

[cx-7heaven 10+ year member]

Yeah, the Dodge in my sig. all wired in parallell with no isolator. To be honest, I didn't ever run the system without the truck running, so it was a bit redundant in my setup. If you have a powerful system that causes a lot of voltage sag, then a high output alt may be a better choice for you. If you do a lot of car off demoing, then extra batts ands a highoutput alt would be needed.

 

[Mommy Wagon 10+ year member]

I will be adding a 300A alternator as well, I just want to make sure the system has more than I need for the time being.

I just haven't seen anyone run a single alternator direct to 2 batteries before. Seemed like a good idea and that it would work, my only reall concern was how does the system know which direction or battery to charge if they are both directly wired to the alternator?

Will a battery overcharge from the alternator, there is no failsafe then?

 

[mylows10 5,000+ posts]

you'll be fine either way ,i ran 3 batteries off my last big system, no issue what so ever .usually not recommended to remove the stock wires ,just to be safe tho.leave them alone and just add the new ones .it still can be done very clean looking if you take your time .

 

[SourDeez 10+ year member]

You are generally not supposed to move stock wiring its stupid to remove it