Dual battery wiring tutorial (and why)

[audiolife 5,000+ posts]

for the POS+ runs....does it matter to go straight from the alt+ back to the back batts or go POS+ from front batt+ to rear batt+?

depends on the power you are running and the size of the battery bank in back.If it is a straight 2500-4000 watt system I would go through the front battery, if you are running 6000+ watts and have 3 or more batteries in back go off the alt

 

[pearlsjam79 10+ year member]

Ok, so let me get this strait. I am going to run two batts. One fuse in on each batt, got it. The batt will be like a distro block. 1/0 ga to 2 runs of 4 ga. I also need to fuse both runs of 4 ga wire? This is all in the cab of a pick up truck and my runs of 4 ga wire will be 3-5 feet max. Not much room to work with.

 

[audiolife 5,000+ posts]

Just pay attention between the batterys on this pic. How you fuse your amps will be dependent on if they have fuses or need fuse holders. You are still going to want to fuse within 24" of the amps if they have no on board fusing.

 

[pearlsjam79 10+ year member]

Perfect, thanks. That helps a lot. One more question. According to that pic, I ground the amps to the neg post of the back batt? Not to the vehicle frame? I am I seeing that correctly?

 

[audiolife 5,000+ posts]

Yup, you can try it either way.You have an advantage of having a full framed vehicle, most vehicles are not.

 

[77oldsMAbrotha 10+ year member]

where would an isolator be placed?between the in-line fusing?

Just pay attention between the batterys on this pic. How you fuse your amps will be dependent on if they have fuses or need fuse holders. You are still going to want to fuse within 24" of the amps if they have no on board fusing.

 

[d77543020 10+ year member]

so dont ground the second battery to the chassis in the back?

 

[audiolife 5,000+ posts]

You can but in a unibody car its better to ground to the alt bracket or the front battery.

 

[tc300 10+ year member]

You can but in a unibody car its better to ground to the alt bracket or the front battery.

are GP's unibodys..?? i cant remember.. LOL

nevermind, i just googled it

 

[tc300 10+ year member]

You can but in a unibody car its better to ground to the alt bracket or the front battery.

what are the cons of grounding an xtra bat in the trunk??? i have a redtop thats grounded like that...

 

[audiolife 5,000+ posts]

ground loop in the charging system back battery gets a weak charge

 

[tc300 10+ year member]

ground loop in the charging system back battery gets a weak charge

So I would have to run another (ground) wire up to the front bat then??

Iv had it grounded in the trunk for 6+ yrs.. The bat is a redtop(stock bat up front) never had any charging problems.. Well atleast not I know of. Amp is a mmats dhcx2200.1

The amp

 

[iroller 10+ year member]

All this info is great and has helped a lot. What do you experts think about the new 14V batteries ? I have a 502BB chevy and it could use move starting power along with my amps, was told you can use the 14V to run all the items in the car without harming them ? If it makes a difference I don't have a computer it's a old 1968. Thanks for your help.

 

[lilbear]

Just checking.... Don't have to tell me 8 times! I always get it by the 7th.. :0/

So, If I have a new DS powerfull 675CA battery in the front, And I run 0-AWG Welding cable to the back Both (+)( -) Cables from the front battery, And I installed two Kenteik 2400s I would hurt the batterys? Beacuse I dont have a 2400 in the front? I can kinda see a point, I never listen to tunes without the Alt turning. Would that matter? Also after I install and when I start the car would it not twist my starter right off the engine?? :O)~

Thanks for any input..

Lilbear

 

[swollen_cu 10+ year member]

Sorry to revive such an old thread, but it's better than starting a new thread...

I have an optima yellow top in my car right now and want to wire in a second battery in the trunk BUT does it have to be a yellow top or can I go with something like a XS power, shuriken or kinetic?

Also, will adding a second battery make the stock alternator work harder in charging the system or will everything run normally?