Dual battery wiring tutorial (and why)

[IDSkoT 5,000+ posts]

Fuse C is worthless. The fuse on the amp will blow if the amperage is excessive.

 

[jco1385 5,000+ posts]

Fuse C is worthless. The fuse on the amp will blow if the amperage is excessive.

what about amps that are NOT internally used?

BTW, this needs to be stickied up there with the big 3 thread that no one see's //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif

 

[loopkiller 10+ year member]

Fuse C is worthless. The fuse on the amp will blow if the amperage is excessive.

How does the amps internal fuse protect WIRE 2 from a dead short?

 

[Proximity 10+ year member]

Seems to me like the ground to chassis for the second battery is redundant.

 

[Crzy 10+ year member]

if an isolator is used between front and rearbattery cant they be different models since they are not connected?

would figure you only mean dissimilar batteries can not be used when wired directly to one another?

 

[loopkiller 10+ year member]

Seems to me like the ground to chassis for the second battery is redundant.

There are some very remotely possible scenarios where the rear ground would be necessary, but they are pretty far fetched. It is really a backup for the front chassis ground. It is the one component in the whole tutorial that is somewhat optional.

 

[loopkiller 10+ year member]

if an isolator is used between front and rearbattery cant they be different models since they are not connected?
would figure you only mean dissimilar batteries can not be used when wired directly to one another?

Yes a battery isolator would allow dissimilar batteries to be "connected". The term connected is used loosely here because they would be isolated and not really connected.

 

[Savag3 10+ year member]

what i would do is get rid of the yellow top and run your system to see how bad the volt drops are. and if they are bad just get a kinetik that is equal to the yellow top

ya the thing is I have four yellow tops and three kinetiks

 

[Crzy 10+ year member]

Yes a battery isolator would allow dissimilar batteries to be "connected". The term connected is used loosely here because they would be isolated and not really connected.

figured, might want too ad that to op as to not scare people who dont know any better into buying a new front battery too

 

[loopkiller 10+ year member]

figured, might want too ad that to op as to not scare people who dont know any better into buying a new front battery too

Done. Thnx //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[IDSkoT 5,000+ posts]

How does the amps internal fuse protect WIRE 2 from a dead short?

True. However, if the fuse isn't DIRECTLY after the battery, the fuse is pointless. Even still, the odds of that wire having a short is very low seeing how most people's extra batteries are next to their amps.

I understand the theory, however I don't believe it's as important as most of you make it seem. For a long run, which is more likely to have a pinch point / part get exposed just because of the length, I agree you should put a fuse. But for a short piece, the odds of it grounding is really low. Especially in the trunk. If the wire is exposed, it can only get grounded on the amp's case, or... carpet. =|

 

[loopkiller 10+ year member]

True. However, if the fuse isn't DIRECTLY after the battery, the fuse is pointless. Even still, the odds of that wire having a short is very low seeing how most people's extra batteries are next to their amps.I understand the theory, however I don't believe it's as important as most of you make it seem. For a long run, which is more likely to have a pinch point / part get exposed just because of the length, I agree you should put a fuse. But for a short piece, the odds of it grounding is really low. Especially in the trunk. If the wire is exposed, it can only get grounded on the amp's case, or... carpet. =|

What if the amp connection comes loose and the WIRE 2 falls out of the amp? If it moves just an inch, it will hit the amp case which is grounded. Voila... dead short. Now the real question is, do you have a fuse that will blow, or is that wire catching on fire? The length of the wire is not important (not really).

 

[Buck 5,000+ posts]

Finally man. Sometimes it's hard to connect + to - for some people.

The fusing is right //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

Looks good.

 

[JarvisB 10+ year member]

Some people again would tell you to not wire this to the battery, but instead to the chassis. This would be OK if you did not have a rear battery and you had a very small amp. But since this discussion is assuming the rear battery is installed, you need to wire the NEG- connection for the amp directly to the battery.

Let's say I am going to run both of my batteries up front under the hood.. then wiring up the negatives together should not be a problem but do I even need to do that? is there different wiring diagram if I have 2 batteries up front?

FUSE A

This fuse should be located as close to the POS+ post of the front battery as possible. This fuse should be rated to match the current rating of WIRE 1. If you are using a single run of 1/0 awg wire for WIRE 1 and it is rated up to 300A, then FUSE A should be rated at the same 300A.

I plan to fuse everything just like you showed/explained in the picture.. I am going to use 1/0 gauge wire so I guess I should have 300A fuse on all of the fuse holders? I will be powering a kicker zx2500.1..

this is a off topic question- I am wondering if you could tell me which size fuse should I use to put in the wire between my 250A HO alternator and front battery's positive post? should it be 250A or should I just get a 300A because 250 might be too close and it might blow if the alternator produces more power somehow?

 

[Xprime4 10+ year member]

nice explanation once again Loop!

I'll make sure to direct ground my rear batt to my front on my next car, hopefully soon!