wiring up 2nd battery..

[KyleBechtold 5,000+ posts]

Alright I think i got this down but not %100

1.) Positive from front batt to second batt

2.) 2 Fuses 18" or closer from the batteries one on each side

3.) Ground the negative from the second battery as close as possible on a good ground..

4.) positive from 2nd batt to amp with fuse close to the battery..

Did i miss anything? also would it be better to run the negative from 2nd to chassis or 1st battery?

for the fuses between batts should i use 300 anl fuses?

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[KyleBechtold 5,000+ posts]

hello

 

[DBBOOM 10+ year member]

You 're correct, i would use as small of a fuse as my amp would allow. But 300 will work, if your wire is rated for 300. Chasis ground should be fine for second battery.

 

[KyleBechtold 5,000+ posts]

no not that fuse the fuse between the two batteries.. or is that what you are talking about?

 

[DBBOOM 10+ year member]

Im talking about the 2 inline safety fuses, 300 will be fine, i run as low as possible. That way they will blow easier in the event of a short in the cable.

 

[169db 10+ year member]

what do u do with the negative up front ?

 

[jco1385 5,000+ posts]

what do u do with the negative up front ?

ground it out to the frame and the engine (look into the big 3)

 

[skmfkr 5,000+ posts]

You 're correct, i would use as small of a fuse as my amp would allow. But 300 will work, if your wire is rated for 300. Chasis ground should be fine for second battery.

x2 i used 3 200a fuses, and i ran 1/0 neg to neg

 

[PSturmer 10+ year member]

i always do neg to neg on batteries. never ground them. if its a daily system fuse the pos cable on either end, it does not matter what size fuse it is.

 

[KyleBechtold 5,000+ posts]

isnt the smaller the fuse the less that can travel through it? also the battery will be so far back the ground on the frame will most likely be the best for me

 

[KyleBechtold 5,000+ posts]

also.. the way i plan on wiring it.. will the first batt charge the second? or will i need to? its for daily so i only use with system on..

 

[jco1385 5,000+ posts]

are the batteries in parallel with out an isolator? if so, the alt will charge them both. it will be fine.

btw, i use 2x 300a for my battery wire (front - rear)

 

[KyleBechtold 5,000+ posts]

are the batteries in parallel with out an isolator? if so, the alt will charge them both. it will be fine.
btw, i use 2x 300a for my battery wire (front - rear)

parallel by the neg-neg and pos - pos.. then yes.. no i didn't get an isolator as i won't be running this while my car is off...

 

[jco1385 5,000+ posts]

parallel by the neg-neg and pos - pos.. then yes.. no i didn't get an isolator as i won't be running this while my car is off...

then you're all set

 

[KyleBechtold 5,000+ posts]

will my alt have to work harder then?