1990 camaro 305 tbi---i am having trouble with my car battery dieing when i run the stereo with the car off. i want it to last longer with enough power to crank the engine over. as of now i can only run the stereo with key off for about 3 minutes. ive heard of running dual battery but i am afraid of fire or shorting something out. ive also seen a cylinder looking thing that helps buy letting the stereo take juice from it instead of the battery directly...
any help will be very appreciated

 

Is Your battery old ? I can run my system which sucks alot of juice, got 2g hooked up to it, and it will last an hour easy semi loud.

3 mins battery might be shot :/

What are you pushing ?

 

go buy yourself an optima red top.
get the biggest one autozone or whoever you go to will make fit.
then if you are still having problems, wire your old one in with it.

i agree that either your alternator or battery is on its way out though.
i can run my stereo (with key on and engine off, ie, not on stereo only circuit) for over half an hour without putting a dent in the battery.

granted this is on a brand spanking new optima, but it shouldn't be a problem for any decent battery.

i once left my lights on and remembered 3.5 hours later.
went running out to find that my lights, although not super bright were not out yet.
turned them off and the car cranked.
i love my good battery.

i guess if you are running over 1000w of power to more than 2 subs and have all your component speakers amplified as well and are running them all at high power, i could see you running out of juice, but really, i think you need a new battery.

 

yes its very old but it is stillpushes out 12.57 volts off and 14.46 running
i got 2 fosgate 10 in subs with 2 amps one 60 and one 40 watt amp..all custom and done professionally...
i also bought the car and found out that it has blue neon underglow that i never use.

 

I am running dual batteries but I also have a 230amp alt with wire upgrade and I am running a 1800 and a 1200 4ch amps. I can run my stereo for a couple hours but what matters is the class of your amp not the amp output. If you have a class A/B amp it will be very power efficient compared to a class C or D and god forbid those Monster class D amps like the audiobahn 2300 that will turn a car off from just soaking the power.

Get a Optima yellow top but if you feeling frisky go for the blue top (Marine) and have power to spare. I am running two regular batteries but that is because I was cheap at the time but I will be going yellow top with a hell of a battery isolator just to be safe.

 

with the amps you are running, you shouldnt have a problem with your battery.
get a new one.
if you are still having problems, run your old one as a backup

 

go to auto zone and get the free test so you don't go buying one thing and needing the other. i did it and its frustrating to drop all that cash when i did not need to.

 

the cylinder thing that you were talking about is called a compositor so you know and they are very helpful when running a lot of power from a battery. and just because your battey puts out 12.57 volts doesnt mean that its good. my battery did that and it had 214 cold cranking amps (CCA) and my car wouldnt start with the stereo on so i had to go get a new one. i got the optima red top and it is great i dont have any battery problems anymore and if you do i would buy a compasitor to see if the helps and if not you might have some other problem.

 

alrighty thanks for everything i really appreciate it..doesanyonenow how to curcit two batteries together...i dont have the money far an optima and a compasitor just yet but i have a fairlynew top post battery i would like toaddtill i can afford the good stuff...

 

for dual batteries an isolator is used-basicly a big diode
that lets the electrical system charge the auxillary
battery, but does not let current from the auxillary batt.
flow back to the main battery or vice-versa, that way
the batts can't discharge each other.Battery isolator is
commonly used with campers and RVs.If properly done
and fused right dual battery system will be reliable and
safe.

 

you might could get a bigger alternator like one off of a police package?

 

12.57 volts off is quite low actually, 12.75 is considered 100%. What is the voltage with the lights on, and how long can they stay on before giving you trouble? 14.46 running is an indication that your alternator is working perfectly. I think you just need a new battery, or you can try to see if a long-term trickle charge will help some.

 

Power output has nothing to with load capacity/life length.

Even if it puts out GREAT power, that doesn't mean it is retaining any of it (holding a charge).

You definately need a new battery.