2 Batteries

[slimx]

Ok dont ask why, i want to.. do it . I lvoe my integra :) and i feel like putting a battery in it 4 fun lol

I want to run a 2nd battery, the 2nd battery i have is a MOTORCYCLE battery, its compact tiny, n shit .. its gona run my amps dis dat..

Now knowing my luck this wont be simple, i doubt i can just run a positive and a negative from the original battery to this 2nd battery. Or is it ?

If i cant, WHY? what happens if i do?

If i can, thanks :) WOW first time something was easy.

If i can but i need shit, what do i need and how :)

[xclusive_eg8]

Moto battery gona output enough to run the amps??

[slimx]

oh yes definately, my power isnt the issue, its mainly an earthing issue i have.
I got alot of high power stuff, everything earthed to the chassis starting to **** up a few things.

I want to run a direct earth to the negative of the battery but i dont wanna **** around with 10 cables going to the negative of that 1 main car battery. and that might just strain it more i presume. My battery is already like gona die im amazed its lasted a year the way i been abusing it lol.

So yeh.. does anyone .. know anything bout hooking up 2 batteries .. could i just run it or whatever?? someone anyone.

[xclusive_eg8]

It's possible mam, think there was a DIY on ozhonda or boostcrusing on this....just google it heaps of info, but remember batterys can output as much input...so check alternator, do big 5 upgrade then decide on dual battery

[aaronng]

I want to run a direct earth to the negative of the battery but i dont wanna **** around with 10 cables going to the negative of that 1 main car battery. and that might just strain it more i presume. My battery is already like gona die im amazed its lasted a year the way i been abusing it lol.

If you follow the negative of your current battery, it goes to the chassis, which means the chassis has the same potential voltage as the negative battery. So wiring it up to the chassis will be similar to wiring it up straight to the battery.

[crazy2287]

yeah, the simplest instillation will require, id recommend, min 4awg positive between battery's positive's. minimum 1 breaker or fuse ~100A depending on useage. if the wire run is long, (ie, under bonnet to boot) then install a breaker at each end (2 breakers/fuses), as close to the battery as possible. This will ensure should anything happen to the cable then your car wont catch on fire. cuz that shit will ruin ur day. having a trippable breaker is handy as you can isolate the battery by the flick of a switch for maintenance or to prevent draining of factory fitted battery.
put a 4awg from original battery to chassis and/or upgrade the factory negative to a larger dia wire (4awg or greater) If factory earth wire is terminated to engine make sure your engine to chassis wire is upgraded as well or you risk weird shit happening like melting your accelerator cable.

The new battery's neg terminal terminates directly to chassis.

run the positive away from ECU's and audio equipment if possible as the high current CAN cause interference. But keep all wires as short as is practically possible.

install either a fully sealed battery and fix properly to chassis, or install in a battery box that is vented outside the cabin. this is a safety issue.

obviously if you are doing this to sold a power supply issue you need to asses weather the fault is atcually an underrated/warn alternator.

[WhiteKight]

You will need to run a lock off system to have any advantage. You can buy kits from places like Oppiste Lock and ARB. Its more of a 4X4 thing.......


What are you trying to gain by doing this ? If you want to throw your cash away give it to carrity

[slimx]

i gota really big setup, as a result.. when i turn on headlgihts they often intefere with sound system, high beams, interior light, blinkers, sunroof, windows, etc..
I've already been checked by the professionals, all i ever get is .. to much hoooked up, too much this , to much that.

As for NEGATIVE being connected to chassis. Thats like one of my questions, ive tested everything and it just seesm to be the earthing issue, if i earth my amps and what not to another CAR. i dont have any issues. I tried power, but i still had the probelm so it has to be something in the earthing all the audio and auto electyricians are telling me my chassis has to much earthed to it :S i didnt know that was possible? lol

I asked them all about a 2nd battery, half of them make up shit .. saying to install it u need blah blah cost $800 wtf lol.

the bloke who said i should fuse them, thank you ill make sure i put a fuse on both ends just to be EXTRA safe.
Wires are just gona be run through like any other um.. amp cable? through the firewall, under the carpet. away from RCA's. opposite size. Parrallel under the rear seat. and the battery will be mounted, in a custom made mount.. or wtaeva i dno ill make something out of wood for it. thats easy.. I just have safety issues.

I dont wanna blow anyting up.

and i cbf checking but someone said something about straining the alternator. I was actualy told and ive dfone a fair bit of reading that THIS WOULD HELP the alternator? It'll make the alternator work less because whenever the battery starts running out .. the alternator works hard, but wen u have t2 batterys it wont run ou tso quick infact it should take much longer.

Another issue ive also had and reason why i wana do this is.. if i turn the music up loud enough.. my car can stall, it idles to 0. Doesnt quite stall but is like JUST about to lol. im sure if i play a song that has enough bass for about 10 seconds it'll turn off lol. I THINK, dont know but i RECKON it might also stop that.

As for throwing away cash as i stated before. I HAVE A MOTORCYCLE battery at home, its der, its useless, its BRRAND NEW lol.
and wiring is like $10.

[vinnY]

just sounds like electrical interference, running those rca cables near the power cables?
the engine block is pretty much the ground for the entire car which are connected to the chassis via the engine mounts - edit; i stand corrected :)
i'm pretty sure you can't have *too many* grounds, just not done well

[crazy2287]

the engine dose not ground through the mounts as they are generally rubber mounted. The car will require an earth cable running (in the case of what im familait with) off the bell housing/transmission to the chassis to acquire a proper ground.
One of the first few things i do when i install a stereo system is add an earth from the battery to chassis as big as the wire i have used for the amp. or increase the size of the factory wire, till its rating is that of the original earth + the capacity of the amps supply wire.

A second battery is only going to help you if your average load is under the rated output of your alternator.
For example. I have a dual battery setup in my car and a 120A alternator. My stereo system when cranked at full blast will draw a maximum of 480A @ 12.5V or a constant of 200A @ 12.5V
As you can see this is above the rating of the alternator, if i were to pump the sound system full bore and add a 50HZ tone to the woofer channel i, Besides blowing somethign up, would drain the batteries.
But because on average i don't have the stereo at full blast, in fact well under. and because the bass only his on the beat, my average consumption would be well below 100A
The alternator provides 14.4V nominal. so when the car is running the alternator will provide all the current your car needs until it get so heavily loaded that its output drops to that of the native voltage of the batter. 12.4ish at which point the battery's will start providing the bulk of the current.
The simplest way to see if you need a larger capacity alternator is run the car at 1000rpm, turn on all electrics and place a multimeter across the battery terminals. If your voltage is below 12.4V then your battery is draining. the only way to prevent this (unless its an electrical fault) is to upgrade your alternator.
things that you will use for an extended period that should be on for the test. front demister fan on full, rear demister, headlights on high beam, stereo system and possibly window wipers. though i usually omit window wipers for the test.

check you alternator cable is big enough, up to 50A alt use an 8awg wire from alternator to battery positive.50-80 use 6awg. 80-120 use 4 awg.
those figures are just a guide, for anything better Google it.
check all your contacts are making proper contact, touching conductive surfaces should have no dirt or paint between them. polish them with a piece of sandpaper or scotchbright.

you don't need any fancy lock off or anything for your basic dual battery setup. people who tell you that are making it more complicated then it needs to be. If you are building a 4wd camping/shooting beast then yes. But seriously how often are you going to be pulling over, turning off your car and turning on your stereo system at full blast for like an hour or more?
And on the RARE occasion that you do, do that. a decent bussman breaker provides a "test" button, use it to trip the breaker and your battery's are now independent. It only takes a second. breakers are like $35, those solenoids your talking about are $$$ especially if you want a decent one.

also you will find the 4awg cable around $8+ per meter or 0awg at $12+ per meter. Please use terminals! Any reputable auto electrician will have the terminals for this size cable and a crimping tool. Ask really nice and you will save $$$ as supercheap and other retail prices are frigging ridiculous.

[vinnY]

^ i stand corrected :)

[slimx]

so basically.. re-earth the **** out of battery, refurbish alternator wiring/cables. and i should be right?

I went to a shop today, the guy explained it PROPERLY why anyone would say something stupid like that.

App earntly when having a big setup its good to earth your battery more, run a few more wires preferably leading more towards the rear of the car. aswell as a bit more on the front to. This will give the chassis a bigger current i believe? helping solve my earthing issue.

As for the second battery issue u seem right, i was just curious whether it would help me solve these problems, oh and i tried it last night. No it doesnt lol. Doesnt do shit.. same problems, obviously would providef a bigger longer lasting supply thats about it.

but yeh i figured out the Battery earthing thing-o i just did a small test run and it worked.
Im gona do a nice clean setup of earthing my battery a bit more. and yeh hopefully everything will be ok.

[crazy2287]

Sorry dude, unless you own a plastic car, ie: v12 Corvett ect then your car body is just a big chunk of metal. Replacing the big chunk of metal with a big round chunk in the shape of a wire is not gonna do jack.
You need 1, suitably sized wire going to the chassis, terminated correctly. and 1 going to the engine block, terminated correctly. Good quality terminals, wires and terminations are your friend.
Incorrectly terminated earths can cause a voltage with reference to the battery's earth to build up at the junction of the termination. This will cause feedback to any device terminated to the same point, as it will not be seeing true earth and current oscillations can occur. but that's neither here nor there.

If you seriously think you have a huge current demand in your car then just go into the shop and ask for a meter of red and a meter of black zero awg cable. use it for alternator to battery positive, and battery neg to chassis and engine bock.

[quangsuke]

this might be noob, but can someone explain this to me?

so OP wants to use a second battery to power his amp etc?

can't he just run a line from the negative cable from the CAR BATTERY to the second battery's NEGATIVE?

then from the second battery's positive to the amp to run it?
obviously the amp would be grounded aswell.

just connect a switch and fuse from second battery to amp so u dont drain the second battery.
if im wrong please explain.

http://img714.imageshack.us/img714/7938/79374199.jpg

[crazy2287]

no.
the process you have describes is called series hookup, This sill cause the amp to be provided with 24+ volts. definitely a bad idea.
also the battery will never charge in this condition as the alternator would need to provide over 24V

the battery needs to be hooked in parallel (positive to positive) to increase the amp hours available not the voltage. In this case.

[quangsuke]

now that makes more sense.

[crazy2287]

Sorry, I miss read your post. You kinda have the right idea. But your diagram dose not correctly reflect what you posted. in the diagram the total potential that the amp would receive is zero volts. (there may be a tiny voltage but that would just be caused by the difference in the native voltage of the battery's.

In your actual description your half way there, you also need to connect the battery's positives together. Then they will be configured in parallel. Otherwise only 1 battery at a time would drain, without connecting positives the battery's will be isolated from one another.

[grifty]

why not just buy one of them dual battery kits?

[slimx]

Sorry dude, unless you own a plastic car, ie: v12 Corvett ect then your car body is just a big chunk of metal. Replacing the big chunk of metal with a big round chunk in the shape of a wire is not gonna do jack.
You need 1, suitably sized wire going to the chassis, terminated correctly. and 1 going to the engine block, terminated correctly. Good quality terminals, wires and terminations are your friend.
Incorrectly terminated earths can cause a voltage with reference to the battery's earth to build up at the junction of the termination. This will cause feedback to any device terminated to the same point, as it will not be seeing true earth and current oscillations can occur. but that's neither here nor there.

If you seriously think you have a huge current demand in your car then just go into the shop and ask for a meter of red and a meter of black zero awg cable. use it for alternator to battery positive, and battery neg to chassis and engine bock.

I dno mate.. but it works now so yeh. lol
Now i gota beautiful earth going through the metal lol before i dno lyk it was just shit weak? or i dno fk it was fkd

I fixed the issue, thats what matters just earthed the battery. that did the trick :)

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why not just buy one of them dual battery kits?

I googled around about that. i didnt quite get how it works n shit.. i hate using kits and shit. i tend to like wiring shit up myself. I gave up on the 2nd battery n gave it 2 a friend nyway so this thread can be CLOSED