How To Properly Fuse Amps and Rear Batteries

[dereileak]

Nice diagrams and info!

Thanks!!

[jbondox]

Now try explaining this to some people.... I hear way too often... "it will cause a voltage drop across the fuse and my DB's will go down" but in the same breath they will be the first to complain when something blows up because it was half arsed hooked up....

The ground running battery to battery really isn't going to do anything to help, if one properly abides by the basic installation rules. I tested this back in the old PPI (art series/pro mos) days, and over the years... if anything, when not grounded in the rear and just running the rear battery ground to the front battery, there is a pretty substantial voltage drop.

Now if it was just standardized for safety, like back in the days, then everyone could sleep better at night

fuse any battery 12" or less, I have yet to see an alternator go bad where the battery couldn't absorb the problem (I am sure there is a few out there... but with some silly modified "special" marketed alternator that breaks all laws of physics... and usually doesn't last very long or is trouble free reliable operation

[dereileak]

Now try explaining this to some people.... I hear way too often... "it will cause a voltage drop across the fuse and my DB's will go down" but in the same breath they will be the first to complain when something blows up because it was half arsed hooked up....

The ground running battery to battery really isn't going to do anything to help, if one properly abides by the basic installation rules. I tested this back in the old PPI (art series/pro mos) days, and over the years... if anything, when not grounded in the rear and just running the rear battery ground to the front battery, there is a pretty substantial voltage drop.

Now if it was just standardized for safety, like back in the days, then everyone could sleep better at night

fuse any battery 12" or less, I have yet to see an alternator go bad where the battery couldn't absorb the problem (I am sure there is a few out there... but with some silly modified "special" marketed alternator that breaks all laws of physics... and usually doesn't last very long or is trouble free reliable operation

I personally do not have a second ground wire. The only time I have seen this do any good is for the really really large builds. It all depends on the frame of the vehicle too, as some cars have shitty frames with lots of wield joints, and some have rails that go all the way back up to the front of the vehicle. The reason for fusing the alternator wire is due to the battery still being able to short out. If the wire shorts, the alternator is going to get 0 resistance and go nuts, maxing out its load, and the battery is going to spill its guts due to the same thing. This is why I would fuse on each side, although the chances of something going wrong is low if installed right. Manufactures use fusible links to protect this kind of stuff.

[jbondox]

I am not saying not to, and it is always pretty good to fuse power, especially when adding an alternator that you spent a lot of money on... However, if properly installed and ran like the factory would, your chances of having an issue is slim to none. I ran across many vehicles with fusible links and many without. However todays modern vehicles with computer controlled alternators shut the alternator off if a problem.

Most expensive alternator I have ever held was a $17k water cooled alternator for a Maybach, it was not fused and was being replaced because the diagnostic computer of the vehicle said there was a problem with it, though everything worked

[iKidwell]

glad you made this today, gonna be attempting my first alternator install tomorrow on my explorer, already watched a few vids on it, its a 250a mechman, so should i go ahead and put a 300a fuse on the + wire to battery?

[dereileak]

glad you made this today, gonna be attempting my first alternator install tomorrow on my explorer, already watched a few vids on it, its a 250a mechman, so should i go ahead and put a 300a fuse on the + wire to battery?

thats what I would do, I am sure many people here will disagree, and some will agree. Its safer too, the fuse will blow if anything happens. One of the main things is to run the wire so it has no chance of getting cut and shorting, that is one of the main things.

[lombo352]

With the front and rear battery setup...does the rear battery get charged like the front...and will this stop the lights dimming at stop lights?

[Rebel4055]

With the front and rear battery setup...does the rear battery get charged like the front...and will this stop the lights dimming at stop lights?

Well your probably going to get a butt chewing for saying at stop lights but adding another battery in some cases with a low amount of wattage could help. But if you are like 3K+ then you would want to get a couple batteries and a alt.

You can also do the big3.

[dereileak]

With the front and rear battery setup...does the rear battery get charged like the front...and will this stop the lights dimming at stop lights?

Well your probably going to get a butt chewing for saying at stop lights but adding another battery in some cases with a low amount of wattage could help. But if you are like 3K+ then you would want to get a couple batteries and a alt.

You can also do the big3.

yea, no doubt about it

[Torres]

chart is nice, but i say clean it up a little. it's pretty cluttered as it stands.