00XJ

Hello, I read somewhere that upgrading your battery cables and alternator cables and stuff like that to a thicker wire can make your electrical system more efficient. Any one know if there is any truth to that?

builtnotbought89'

Not "more power" but it will let the power flow easier through the cables! The factory wires are fine & allow the current to flow as much as need be.

TheNerd

Technically, it'll reduce the voltage drop between locations. (And technically, it WILL transmit more power... but nothing you will notice)

V=I*R; and larger wire (smaller guage #) has a lower resistance per length.
P=I^2*R

Similar principle as an upgraded light wiring harness. But as built...89' mentioned, unless you are running a ton of extra accessories, your factory wires are just fine

84wagoneer

exactly. plus considering your battery cables are 3 feet long, there is virtually no volt drop, and if there was any, you vehicle is meant to run on 12v, but when your alternator is charging the system, the system voltage is actually at 14 volts or so. (bad sentence structure, i know )

but, ill stop beatin a dead horse here

5-90

Larger-gage wiring isn't going to give you "more power" - but it will reduce conductor resistance within the wire, reducing drop (which, as stated, isn't that high to begin with.) It also allows for improved current flow with less heat - since OEM wiring is usually considered "just enough for average output" - if you plan on pulling full output from your alternator consistently, or you want to take full advantage of an upgrade, seriously consider going to larger wiring (OEM wiring runs about 8AWG - for alternators north of 80A rated output, that's kinda paltry.)

How much current/power (different, but related) you'll get depend on the source providing it. How much makes it to the user depends on the lead running to it. This is why even stocker headlamps tend to benefit from upgraded wiring, and from using relays fed by the battery directly (shortening the power path by about ten feet, and eliminating the "choke point" of the OEM headlamp switch in the dash.)

If you want to get into a discussion on electrical theory, I'd be happy to oblige you. However, that's probably best done by email, since I won't hit as many limitations as I would here... Let me know if you'd like to get into that - I don't know as much as a full-on EE, but I've been working away at this for a number of years...

Programbo

Speaking as someone who competed in CB radio "keydown" competitions for years and ran high power linears (Ever see 6 Leece Neville alternators in one vehicle?) I know that "thicker" (heavier gauge) cable was the norm for everything involved not because it increased power but because as others have mentioned it allowed more power to pass thru easier and with less resistance

nw-xj-scott

i have 12ft of 4ga wire and terminals waiting to go in.

Fact, the wire between your alt and battery is 10ga.. upgrading that to 4ga will be a decent improvement

another fact: there is one ground going from the battery to the block, then one going from the block to the firewall...

Add another ground to the core support and upgrade the stock ones..

NickM

On my '90, I run #2 from battery to distribution post, battery to starter, battery to block ground, and block to firewall.
Run #4 from alternator to distribution post (150 amp fuse on that one) and alternator case to battery neg.
I noticed after doing that some of my niggling issues went away (door locks work first try, and wierd issue with dome lights coming on when accelerating went away).

Nick

00XJ

wow i glad i made a thread on this it really help thanks for all your input.

scifi266

Stryker should say something about this lol.
On his build he put thicker cable for his ground, and he said it helped with his power windows.

robertj

I'd guess the only reason it helped is because his original ground wire contact was corroded and not effective. Leaving the wire alone while cleaning the contacts would have had the same effect. Thicker wire lets you run the same AMPS over a longer run, so if you were relocating the battery to the back or something I'd suggest it. Otherwise, it's a waste of time and money. You'd be miles ahead to just clean your current ground and wire contacts and leave the existing wiring alone.

raypla

I beg to differ my friend. I put a set of 5 cables from 5-90 on my XJ and noticed quicker cranking time and brighter headlights. Definately reccomended, have you ever looked at your block-chasis ground? It's flipping flat mesh strap, junk. A good $50 spent IMO

TheNerd

Don't get me wrong. I am a big fan of upgrades and I have every intention of getting some upgraded battery cables (in fact, I have 5-90s site bookmarked). I was merely making an assumption about the OP (based on how he worded the question), and how HE would not notice.

Also, I think that proper (factory) battery cable maintenance (i.e. checking the quality of the ground) can go a long way. The mesh strap from the factory is not that bad... its how the ends get all corroded and don't properly ground that causes the most problems.

... so, how long ago did you get those cables? $50 is a great price. I need to pull the trigger on those suckers

sean882

A couple key wires to upgrade would be the ones for the headlights, and reverse lights. I was playing around by the reverse lights trying to figure out a shorting issue I had, and I was only pulling 10.14 volts. I checked the headlights just for fun, and was getting around 10.57 volts. I cut the existing wires heading to the headlights, and used them to power a couple relays (1 for high beam, 1 for low beam). I then ran some 10ga to the relay from the battery, and then straight to the lights. What a difference it made. Of course I used in-line fuses for safety, as well.

alpine.adrenaline

Can anyone recommend a good brand or place to get some burley battery main cables and quality wire?