Using two batteries, parallel? UPDATED

[Phlipbak 10+ year member]

Ok, if I'm going to run two batteries in my trunk, do I wire them parallel to each other? I might be using my stock 770 CCA battery with a Powermaster D3100 AGM battery, and I might be replacing the stock battery with a CCA equivalent Powermaster, but would I wire either of these setups the same? And do I need a fuse in between every connection? I'll have two amps, a ZX650.4 and AQ2200D, the AQ2200D will be ran straight from a battery with 1/0g and the 650.4 straight from a battery with 4g, but how do I do all this and where will I need fuses (in between batteries, amps, etc?)..

Sorry to make new post, old one was getting messy.. thanks!

Trevor

Click to read more...

 

[hoxie08 5,000+ posts]

bout to add me a second batt so im curious as well.

 

[sholiz 10+ year member]

+ to +, - to -

Or ... pos from front battery to pos on one back battery, then pos from the back battery to the pos on the other back battery, and a run between the two rear neg's and one to the frame (or your other run to the neg in the front)

14/16/18v systems differ so I can't answer that

fuse alternator, from front battery, at rear battery, at and then fuse for what your amp rates (ie: mine is 2x250)

don't need to fuse between batteries if a run is

 

[mangel1 10+ year member]

i think you need a isolater between them also from what im reading on here so one battery wont draw from the other

 

[mangel1 10+ year member]

i also read you should put the battery in some kind of casing or box or in the speaker box incase it explodes lol but i did read that.

 

[HellsRise 10+ year member]

If you use an isolator, you need it between the main battery (under the hood) and the run(s) of wire to the back. You don't need an isolator between the back two batteries though.

 

[Phlipbak 10+ year member]

+ to +, - to -
Or ... pos from front battery to pos on one back battery, then pos from the back battery to the pos on the other back battery, and a run between the two rear neg's and one to the frame (or your other run to the neg in the front)

14/16/18v systems differ so I can't answer that

fuse alternator, from front battery, at rear battery, at and then fuse for what your amp rates (ie: mine is 2x250)

don't need to fuse between batteries if a run is

Ok, well do I still need a fuse from rear batt to amps if they have built-in fuses?

And do I need a 300A fuse at the alt AND other areas of 1/0 that you listed? And btw my rear battery is about a foot to 16 inches from my front battery because my stock battery is in the spare tire area in my trunk //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif so should I fuse between the two still? And how big should it be?

Also, I will run my neg from first battery to neg of second battery and ground both to chassis is that right? Or can I just run neg of first battery to neg of second battery and just ground the first one with 1/0g?

And should I run a 300A fuse at alt and then 300A fuse at first battery since they are like 20ft away?

In other words:

Pos.: Alt--300A------20ft.(ish)--------300A--1st batt (in trunk)--16 inches--2nd batt (in trunk)-2ft---AQ2200D AND 2nd batt (in trunk)---2ft--Kicker ZX650.4

Neg.: Alt---Chassis 1st Batt---Chassis AND 1st Batt---2nd batt

Is this right or do I still need fuses before amps even though I think they are already fused?

O!! And how do I use an isolator?? So that my first batt only powers car electronics and second only powers system??

 

[PSturmer 10+ year member]

if its a daily system and you want to be extra safe then fuse any power source at the source. so before each battery. and you dont need an isolater. i have 2 d3100's and i could run my deck for days with my truck still being able to start.

 

[kovemaster559 5,000+ posts]

you don't need an isolator. they aren't all that good unless you plan to use the car on off all the time which is not good for your batts

 

[Phlipbak 10+ year member]

Ok cool, so should I fuse at the alt pos. then at the other end of that same pos. right at the battery (both being 300A?) and then fuse the pos. from 1st batt to pos. of second batt (300A), and then 200A before the AQ2200D and 80A before the ZX650.4? So 5 inline fuses total? (thats expensive haha..)

 

[kovemaster559 5,000+ posts]

Ok cool, so should I fuse at the alt pos. then at the other end of that same pos. right at the battery (both being 300A?) and then fuse the pos. from 1st batt to pos. of second batt (300A), and then 200A before the AQ2200D and 80A before the ZX650.4? So 5 inline fuses total? (thats expensive haha..)

i only fuse the wire that conncet the alt to the batt. everything else is unfused.(i know everything is connected right,2. resistance) its up to you . your car . fuses= insurance. but if you are safe you dont need it