Question about running a Dual Battery System...

[revrider1 5,000+ posts]

this is a very interesting read i must say...

Why yes it is.

 

[Alexwaves 10+ year member]

here is a question for the wise....... say i had a stock alt 75 amp and two stock batterys one in the front and one in the back it would be point less unless i have a isolator which to my understanding only lets the power/current flow oneway.... so when i have my headlights on that power/current would come out of the battery under the hood only...

 

[revrider1 5,000+ posts]

here is a question for the wise....... say i had a stock alt 75 amp and two stock batterys one in the front and one in the back it would be point less unless i have a isolator which to my understanding only lets the power/current flow oneway.... so when i have my headlights on that power/current would come out of the battery under the hood only...

Yes

 

[tommyk90 5,000+ posts]

here is a question for the wise....... say i had a stock alt 75 amp and two stock batterys one in the front and one in the back it would be point less unless i have a isolator which to my understanding only lets the power/current flow oneway.... so when i have my headlights on that power/current would come out of the battery under the hood only...

Thats only when you have the car OFF i believe.

The isolator has a relay that has to be wired up to your ignition wire. When you turn the car on, the relay turns the isolator "off" essentially, letting the rear battery charge off the alternator.

Turn your car off and the isolator opens up and separates the rear battery from the front one.

But, if you run a dual battery setup, the rear battery has to be grounded as well (whether to the chassis or another run of 1/0 to the front battery). You can't just run the positive wire from the front to the rear battery, and attach the AMP's ground to the rear batteries negative terminal.

The rear battery has to be grounded to the whole system. IIRC The rear battery isn't going to charge if it doesn't have a ground to the chassis or front battery.

 

[Alexwaves 10+ year member]

then it would be point less the wire up a second battery with out a isolator

 

[tommyk90 5,000+ posts]

then it would be point less the wire up a second battery with out a isolator

You don't need an isolator. It's only purpose is to keep your front (main) battery from dying if you are playing the system for a long time.

 

[revrider1 5,000+ posts]

Thats only when you have the car OFF i believe.
The isolator has a relay that has to be wired up to your ignition wire. When you turn the car on, the relay turns the isolator "off" essentially, letting the rear battery charge off the alternator.

Turn your car off and the isolator opens up and separates the rear battery from the front one.

But, if you run a dual battery setup, the rear battery has to be grounded as well (whether to the chassis or another run of 1/0 to the front battery). You can't just run the positive wire from the front to the rear battery, and attach the AMP's ground to the rear batteries negative terminal.

The rear battery has to be grounded to the whole system. IIRC The rear battery isn't going to charge if it doesn't have a ground to the chassis or front battery.

//content.invisioncic.com/y282845/emoticons/handclap.gif.0c301076f534e244f0460706894f19e0.gif

 

[stones 10+ year member]

Read this.

http://forum.sounddomain.com/forum/ultimatebb.cgi?ubb=get_topic;f=5;t=009326;p=

Do it!, do it now.

Or else..

 

[Blazin_Jason 10+ year member]

If you don't use an isolator you get double the capacity and double the discharge rate.

 

[revrider1 5,000+ posts]

If you don't use an isolator you get double the capacity and double the discharge rate.

Yes

 

[Alexwaves 10+ year member]

with the car key turned to acc???

now next question say i had the stock alt and 2 stock batterys is there any point....of wiring that up not using a isolator

 

[revrider1 5,000+ posts]

with the car key turned to acc???now next question say i had the stock alt and 2 stock batterys is there any point....of wiring that up not using a isolator

No

 

[tommyk90 5,000+ posts]

//content.invisioncic.com/y282845/emoticons/handclap.gif.0c301076f534e244f0460706894f19e0.gif

I can be helpful from time to time //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

If you don't use an isolator you get double the capacity and double the discharge rate.

But you run the risk of draining both batteries if you run the system for a long period of time with the car off. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

But in most cases, two batteries will power a normal system for a good period of time before the batteries can no longer start the car.

 

[revrider1 5,000+ posts]

I can be helpful from time to time //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif


But you run the risk of draining both batteries if you run the system for a long period of time with the car off. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

But in most cases, two batteries will power a normal system for a good period of time before the batteries can no longer start the car.

Thank you for helping me make my point about a battery isolator. When you have had a HUGE stereo system it is a necesity, unless you want to stay stranded with a dead battery.//content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[knukonceptz 10+ year member]

So what do you do when the battery in the trunk dies:eyebrow: .

Why would you think the rear battery would die? It gets power from the front battery and is grounded so it gets the same charge the front battery gets.

EDIT - Crap - did not see page 2.....carry on