Dual battery setup

Ok I'm new to the forum and to car audio in general but I have some questions about a dual battery setup and any help would be appreciated. If I have two batteries one under the hood and one in the trunk and I have them hooked up like this: Alternator hooked up normally to the front battery and then a 4awg wire from the front and rear batteries' positive terminals to a distribution block which has wires going to all of my amplifiers. Then the total current drain from the distribution block is divided up equally on each wire correct? Will this setup result in the batteries draining each other as I have read in some places? I am looking to go with 2 yellow tops for my battery selection and I read some places that even they need to be vented is this true? Any help would be appreciated.

do it like this, get a split charge relay kit, its a basic thing you need when installing two batteries. now when its connected you're amps will run off the battery in your trunk. this just allows both batteries to be charged properly. Buy a kit, smack it onto the batteries. Now you gotta look at the alternator and see if its cut out to produce enough for two batteries.  dats all for now!6* Rockford T2's

6* POWER AMPs

BLACK CORRADO

BAANNGGIINN

Nope. I disagree completely. Use NO isolators at all, and simply wire the two batteries in parallel. An additional battery is only going to be MAYBE two or four more amps required for charging, BUT the batteries must be the same age, capacity and type... if you are buying one with any type of isolator, then forget the isolation altogether, and plunk that cash on a second identical battery.It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Ok but if I use this isn't it the same as using an isolator? if so then won't I have to have the total power that is used by the audio system go thru it?... what I'm trying to avoid is running anything larger than a 4 awg wire from my front battery because there simply is no way a larger wire would fit without me taking out half of the items under the hood to have a good place to drill. I'm trying to not only set this up for the system I will have but to be a little flexible in the future If I had the wiring as I mentioned earlier what are the con's to that? I'm not someone who plays their system very much without the car running I know I will need a bigger alt so I'm not expecting the dual batteries to solve all of my problems.... Ok wait I've read more about these while writing this post... so is this how it works... I connect the wire to the + on the front battery to the split charger then it to the rear battery and then the rear to the audio I can have it(rear battery) isolated from the other one... but won't I eventually have to have this set to be connected so that the alt will charge both so I'd either have to have the wire on this thing capable of handling my entire audio system or connect it, while the engine is running, with my audio system set to a low volume to recharge the rear battery???? confused cause I know that a DC flow only goes in one direction and that electrons actual flow is neg to pos but everything is always in conventional flow so it confuses me lol I'm very confused lol.

the connection I'm talking about is like this at the bottom of this page... http://www.bcae1.com/battiso.htm if I do this the current draw from the distribution block with be half from the front and half from the rear correct? I REALLY want an answer to that question =-) I also see some posts of people saying even if you have two of the same battery that unless they are from the same batch that the will slowly drain each other when you have the car turned off is this correct?

I was in the mindset of getting two yellow tops do you have any other suggestions haemphyst? I'm open to suggestions but I don't see where you really have to have an Isolator unless you'll be running your tunes all the time without running the car and for the isolator setups I have to have full power for my system going thru it which if I had something really power hungry wouldn't be possible because the power wire I'd need to run would be to big.

1: Forget the "split-charger" 2: You STILL have to have that large a wire, because your ALTERNATOR should be big enough to make any amount of power you might need. You are upgrading your alternator, right? You are correct. Dual batteries will NOT sove your problems... It won't "solve" any of them. 3: You are correct, the diagram at the bottom is the one you want to use. You can modify as you would like, just be certain your power cables are fused at both ends, and the batteries are paralleled...It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

S0 whatever my total amp current draw is that write going from the front battery to the distribution block has to be rated to handle that draw? what about the wire from the rear battery? Is it then only suppling power when the main one isn't? how is it getting it's charge lol confused again? I know I'm very close to understanding it but I just can't get over the hump lol. here are the reasons I want a dual setup... 1. have less current coming from both batteries so that I don't have to run anything bigger than a 4 awg 2. make wiring easier to say put in some neon lighting and cooling fans, etc... in the trunk that would be controlled by a switch or the car's remote.

Yes I will be upgrading my alternator I'm sure the current 103 amp alternator would be very unhappy if I put all that other stuff on it's load. btw any suggestions on who to get one from? thanks

If I had the same setup as before but ran another 4 awg wire from the rear battery to the alternator then wouldn't it all work out the way I want it to? as in the current draw for the audio system on the fuse block would be divided up from the wire to the rear and front battery and I would get flow from the alt to the batteries and then back.