Battery Questions
06-24-2003, 08:13 PM
#1
50 Watt CAFz'r
Thread Starter
Join Date: Aug 2000
Posts: 410
Well, i know this topic has probably been beat to death somewhere on this forum but i'll ask anyways.
This year i'm planning to build my stereo from the ground up, and first thing i am going to do is make sure i have one hell of an electrical system before i get going with the rest of the setup.
I should probably mention a bit about my stereo. I'm going to be running (2) 12" subs and i'm planning to get an amp at around 1500 watts, i also am planning to run a set of front components so i'll be looking for another amp running around 150x2. sooo... for now i'm imagining running 2 maybe 3 amps so i want a fairly decent supply of power.
I drive a '00 Cavalier, right now i have the stock battery and 112A alternator. I'm thinking of replacing the stock battery with (2) Yellowtops or equivalent sized dry cell batteries one in the front and one in the rear plus seeing if i can get my alternator rewound up to 160A
I'm not sure if (2) optima's would be overkill or not, any idea's?
And also, if i do choose to run (2) yellowtops would i:
a) Wire them in parallel and call it a day.
b) Buy a relay isolator (i think thats what they are called) so when the car is on, they are connected. When its off they are disconnected
So basically this whole post was to get some idea's and comments about the system. Am i on the right coarse thinking about 2 batteries? Should i consider capacitors? Should i get the alternator rewound? Should i only get 1 battery?
Also, i'm planning to run 2/0 wire all around for anyone interested.
This year i'm planning to build my stereo from the ground up, and first thing i am going to do is make sure i have one hell of an electrical system before i get going with the rest of the setup.
I should probably mention a bit about my stereo. I'm going to be running (2) 12" subs and i'm planning to get an amp at around 1500 watts, i also am planning to run a set of front components so i'll be looking for another amp running around 150x2. sooo... for now i'm imagining running 2 maybe 3 amps so i want a fairly decent supply of power.
I drive a '00 Cavalier, right now i have the stock battery and 112A alternator. I'm thinking of replacing the stock battery with (2) Yellowtops or equivalent sized dry cell batteries one in the front and one in the rear plus seeing if i can get my alternator rewound up to 160A
I'm not sure if (2) optima's would be overkill or not, any idea's?
And also, if i do choose to run (2) yellowtops would i:
a) Wire them in parallel and call it a day.
b) Buy a relay isolator (i think thats what they are called) so when the car is on, they are connected. When its off they are disconnected
So basically this whole post was to get some idea's and comments about the system. Am i on the right coarse thinking about 2 batteries? Should i consider capacitors? Should i get the alternator rewound? Should i only get 1 battery?
Also, i'm planning to run 2/0 wire all around for anyone interested.
06-24-2003, 09:45 PM
#2
500 Watt CAFz'r
Join Date: May 2000
Posts: 871
Big Tom, I have a '89 Cavalier Z24. I am running 5 amps with 4 12" subwoofers and front stage speakers. My stock alternator which was only 60amps was rewound to 105amps hot and 130amps cold. I replaced the stock battery with an Optima red top in the front as a starter battery, and an Optima yellow top(deep cycle) in the trunk. There is an isolator which will have both batteries running when the ignition is on and only the Yellow Top working when the ignition is off. This set-up has worked very well for me.
06-25-2003, 01:02 PM
#3
50 Watt CAFz'r
Thread Starter
Join Date: Aug 2000
Posts: 410
I've been curious though, (in your example) with the yellowtop isolated lets say you play your stereo at a bush party or somthing and drain it down pretty bad, once you start your car and now the redtop is in parallel wouldn't that cause an excess of current to be fed into the yellowtop?
Kindof like giving it one hell of a fast charge.
Is that ok for a battery? Or would that screw up the yellowtop after awhile?
Kindof like giving it one hell of a fast charge.
Is that ok for a battery? Or would that screw up the yellowtop after awhile?
06-25-2003, 01:21 PM
#4
Guest
Posts: n/a
^ Inrush current on a 'dead' battery really isn't that much.
In general a battery is 'dead' at 10.5 volts. If your front battery is resting at 13volts and you look at the internal resistance of the battery, add in the resistance of your wire, isolator, and 2 fuses you are going to top out at something like maybe 20-30 amps on the high end. I'm sure someone will fire up a calculator and figure it out
And as the voltage comes up the current draw drops off too.
Anyway, don't worry about it [img]smile.gif[/img]
In general a battery is 'dead' at 10.5 volts. If your front battery is resting at 13volts and you look at the internal resistance of the battery, add in the resistance of your wire, isolator, and 2 fuses you are going to top out at something like maybe 20-30 amps on the high end. I'm sure someone will fire up a calculator and figure it out
And as the voltage comes up the current draw drops off too.Anyway, don't worry about it [img]smile.gif[/img]
06-25-2003, 06:57 PM
#5
1000 Watt CAFz'r
Join Date: Sep 2002
Posts: 1,093
Wire the two batts in parallel, this way it will remain at 12volts total and give you plenty of juice. wireing in series will increase the voltage, in your case it will come to a total of 24volts.
SHY
SHY
06-25-2003, 07:15 PM
#6
50 Watt CAFz'r
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Join Date: Aug 2000
Posts: 410
Dukk: So you give a thumbs up to the isolator idea or just saying **** on it and wire them in parallel?
06-26-2003, 12:55 PM
#8
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I'll agree that if both batteries are new and identical then you may not need any isolation. For the minimal bux it costs I would use an isolating relay anyway [img]graemlins/dunno.gif[/img]
06-26-2003, 09:01 PM
#9
50 Watt CAFz'r
Thread Starter
Join Date: Aug 2000
Posts: 410
Haunz: Yeah, 2/0 maybe a bit overkill but i think i'll use it for my grounds and power fom the alternator/batteries and then upto the distro and then lower it to whatver the max wire size is on my amps. Plus i can get the stuff dirt cheap up to that size so why not eh? 
Dukk: What size of isolator would you think i would need? i've found some 200A models which i think should do the trick
Dukk: What size of isolator would you think i would need? i've found some 200A models which i think should do the trick
06-27-2003, 12:36 PM
#10
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Most people use the 200A relay offered by EFX, Stinger, Wrangler, etc..
They have an 80A one too that would probably be enough but hte 200A isn't all that much more.
They have an 80A one too that would probably be enough but hte 200A isn't all that much more.
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