hi, i want to get a duel battery setup for my car. i was just wondering how you can do this? wether there is a charge box to switch charge from front battery (To start the car and other things like that) to the back one (Sound System Battery) or if you charge them both at the same time? if it is a good idea to have isolators for the 2? and if there are any other problems that i may have with this setup?

unless you really need hte extra power its easy to just get a bigger battery

They will need to be connected in Paralell and would probably need a bigger alternator (someone correct me if im wrong)

Duel battery setup: Whichever is more powerful wins the duel, the other one gets sent to the recharge...:dancin:

If you have a dual battery setup, you can use an isolator so that you are only drawing charge from 1 of the batteries while the car is off.

You can wire dual batteries up in series so that your rear battery is drawing power from the front battery. All you need then is a cable (4guage or larger) running from the front battery to the rear, and the rear battery needs to be earthed (there are places in the boot to do this). When your car is on it will then charge both batteries.
If you are thinking of running your stereo for long periods of time with your car off, then you might want to invest in the isolator so that you will always keep charge in 1 battery so your car will start.

The main reason for a dual battery setup is to limit voltage drop over distance, as a rear battery requires much less cable to amps mounted in the boot. In any case, you should look at a deep cycle battery.

I have a dual battery setup in my car, and have had no probs with the standard alternator. I dont run an isolator either as Im not one to stand around the car pumping tunes in a carpark :P

here is my (ex) professional opinion (was 4x4 parts sales man)

cheap option is something like a redarc(sp?) or tjm/arb/ol soleniod. most can be bought as a kit with all the wiring and such u need.
pros
-cheap
-pretty easy install

cons
- for the love of god DON'T use 2 diff type of batteries. ie. to mount batt in boot needs to be a sealed gel cell type, u MUST change ur front starter batt to a gel cel type (defeating the purpose really). the diff types of batt charge differently and u WILL destroy them by charging disimilar type 2gether.
- need to get a time delay circuit in it or it will connect both batt when starting. deep cycle, gel cell batt in general hate starting cars, they designed for small amounts of draw over time, not the 250-300 odd amp hits a starter gives them, going to kill them pretty quick

Best option is a proper 4wd isolater such as a Rotronics unit.
pros
- completely seperates batteries at start, only allows 1 to be drawn from when ign off.
- depending on model is perfectly fine for disimilar batt types (ie. keep ur lead-acid under bonnet and put a nice gell cell in boot)

cons
- can get very pricey... VERY pricey


Go in to a big 4WD place like Opposite Lock, JM or ARB (personally i say OL, not cause i worked for them, but because i have heard and experienced nothing but bad stories about cust service from the others across aust.) if u tell the guys what u wanna do and that u need to charge disimilar batteries, they will go thru and pick out the best option for u.

PM if u want more help

Tim

If you have a dual battery setup, you can use an isolator so that you are only drawing charge from 1 of the batteries while the car is off.

You can wire dual batteries up in series so that your rear battery is drawing power from the front battery. All you need then is a cable (4guage or larger) running from the front battery to the rear, and the rear battery needs to be earthed (there are places in the boot to do this). When your car is on it will then charge both batteries.
If you are thinking of running your stereo for long periods of time with your car off, then you might want to invest in the isolator so that you will always keep charge in 1 battery so your car will start.

The main reason for a dual battery setup is to limit voltage drop over distance, as a rear battery requires much less cable to amps mounted in the boot. In any case, you should look at a deep cycle battery.

I have a dual battery setup in my car, and have had no probs with the standard alternator. I dont run an isolator either as Im not one to stand around the car pumping tunes in a carpark :P


Now she loves it..:P See no need for 0 Guage and ****..


Dual batterys are for people who are serious.. Its the best way.. I been doing it for years..:) I also recommend it to anyone too..

ive heard that you need a dry cell battery if your adding another battery in the boot just for your amps to run off, is this correct? or was i told aload of crap?

ive heard that you need a dry cell battery if your adding another battery in the boot just for your amps to run off, is this correct? or was i told aload of crap?


Havent heard that before.. ive always run a big heavy duty deep cycle on in the boot..:)

theres only some types of batteries you're legally allowed to have in the boot (considered a passenger compartment) unless its in a properly sealed box with a vent hose to the atmosphere.

dry and gell cell batteries are fine tho

Optima Yellow top or optima redtop are excellent choices for batteries in the rear, for those who don't want to spend a fortune, get a deep cycle marine sealed battery, hey still not too cheap but buy quality and only buy once, buy crap and have to keep going back :doubt:

optimas are getting worse every day. the return rate on them is nearly as bad as a kodak camera these days. they just keep breaking. i'd heavily recommend an Odyssey or Orbital over the Optima any day.

in regards to using 2 different batteries.. ive never heard a bad word about it? there are an incredible amount of SPL cars out there running different batteries front and back, without a hitch.. ive ran dual batt setups with different batts and still get the normal life expectancy out of the batteries.

in reference to whoever mentioned connecting the batteries in series earlier in the thread. this will work... if you want to cook all of the electrics in his car. series batteries = 24V, parallel = 12V and combined draw.

what gear are you running in your car/plan on running? this will really determine what you will need.. i mean, a bloke i know runs 4 rather hefty batteries in the boot and a starter up front.. and still drops down to 9V when turned up.. altho 12,000W RMS has that effect :P

haha 12,0000watt rms :| thats bloody insane haha, so what would you recommend for someone only running a 1000watt rms Crossfire monoblock and a 4 X 100watt rms Mcintosh and audio control active crossover.
I'm looking at going dual battery right now as the possibilities and positives are so much better than any negatives (small negatives, like price of battery, isolation circuit, wiring)
So can't wait!

theres only some types of batteries you're legally allowed to have in the boot (considered a passenger compartment) unless its in a properly sealed box with a vent hose to the atmosphere.

dry and gell cell batteries are fine tho


Didnt think you could put on in the boot without being in a seal battery box..


And you would a freaken idiot not to put in a box..:P

i havent got mine in a box.. it is however, utterly unmovable, secured between sub box and amp rack in my install, and against the back seat :)

im running a 1000W RMS clarion D and 700W RMS crossfire AB and im running little 550CCA Exide Evolution in the boot, works a charm :) very minimal voltage drop on burps with engine off. i wouldnt really recommend spending any more money than that on the ~125A you could draw (at absolute max).

either that or the tiny 680CCA Odyssey, really tiny little battery, and packs a lot of power. and its sealed so safer for a boot environment.. i think they go for around the $200 mark.

for the spl guys if you are in any of the street A, B, C classes your are only allowed 1 battery in stock location


oddessy battery would be my choice i have PC1700 with no problems

[QUOTE=Woob]
i havent got mine in a box.. it is however, utterly unmovable, secured between sub box and amp rack in my install, and against the back seat :)
[QUOTE]

WOW! Thats Dodgy!:gtfo: Go get a battery box.

People, you need to stop being so frugal with the $$$$. You can't put a price on safety!