CarbonMz3 said:
Okay, I have one 600watt 4ch alpine amp that is powering my 2 JLw3v2(and 2 6x8 pioneer 4way 240watt speakers that i just added in the hatch cover). I just bought 2 diamond audio m6-mkii 10in subs & another 1000watt power acoustik amp...
I want to replace my JL's and replace it with the diamond audio subs, and than run it off of the 1000watt amp. ALSO I want to keep the 600watt amp to power all 6 pioneer speakers, and 2 extra pair of tweeters...
Soo~~ If I want to put an extra battery in the hatch, and run it off of the alternator to "repower" it. Would it effect the original battery because the alternator is "repowering" two batteries instead of just one?? Or is there any other way of hooking the extra battery?? Or do I even need one??
Thanks, any input will help at this point.
What model amps are you using?
Why do you want to run 6 speakers and then 2 tweeters on top of that?
Yes, an additional battery will become another load on the alternator. However, its not neccissarily a bad idea. The battery in the car is really only used for starting the car in most cases, then the alternator recharges the power it losed when starting. Once that is done, the main battery is no longer a draw on the system. You could remove it and the car would keep on running. At that point, the alternator would only have to power the rear battery as its reserve is dipped into when the amp draws more power then the alternator can quickly provide. Realisticly though, your main battery can do that too.
Caps typicly are not that usefull. They only release power as the voltage of the system falls. Since a car running is at about 14 volts, the cap only starts to release energy once voltage falls lower then that. Unfortunity, a cap has an internal resistance that it must over come aswell, before releasing power. The higher the ESR of the cap, the more power that will wasted over coming it. This is where high quailty capcitor come into play, although good luck finding an honest compaision test of caps. Once the cap overcomes its own internal resistance, it does not release power like a battery does. A battery will put out a bajesus of power for every volt it falls, a cap won't. Caps really only produce significat power when they can go from full voltage to none instantly. Then they realse there full charge.
Take a flash bulb of a camera as an example. A capitor is used to power the bulb for a very breif burst and does so from its charged volatage to 0 voltage so it releases everything it has to give. A cap in a car will not though. As the car's voltage sags from amplifier demand, the cap will start releasing power based on the voltage drop from its source. Since a battery will "catch" and become the main source of power in a car at 12.6 volts, the cap only works from 14 volts to 12.6. After that the battery takes over and has to charge teh damn cap too. Now if the voltage plumits to say 10 volts and the battey simply can't release power fast enough (by the way, a battery is my no means slow at releasing power) Then the cap is going to discharge its stored power until the battery stabilizes things. The problem is that the cap will likely not have enough power to help out if the voltage is falling that much.
Read from howstuffworks.com
Farads
The unit of capacitance is a
farad. A 1-farad capacitor can store one coulomb (coo-lomb) of charge at 1 volt. A coulomb is 6.25e18 (6.25 * 10^18, or 6.25 billion billion) electrons. One
amp represents a rate of electron flow of 1 coulomb of electrons per second, so a 1-farad capacitor can hold 1 amp-second of electrons at 1 volt.
A 1-farad capacitor would typically be pretty big. It might be as big as a can of tuna or a 1-liter soda bottle, depending on the voltage it can handle. So you typically see capacitors measured in microfarads (millionths of a farad).
To get some perspective on how big a farad is, think about this:
- A typical alkaline AA battery holds about 2.8 amp-hours.
- That means that a AA battery can produce 2.8 amps for an hour at 1.5 volts (about 4.2 watt-hours -- a AA battery can light a 4-watt bulb for a little more than an hour).
- Let's call it 1 volt to make the math easier. To store one AA battery's energy in a capacitor, you would need 3,600 * 2.8 = 10,080 farads to hold it, because an amp-hour is 3,600 amp-seconds.
If it takes something the size of a can of tuna to hold a farad, then 10,080 farads is going to take up a LOT more space than a single AA battery! Obviously, it is impractical to use capacitors to store any significant amount of power unless you do it at a high voltage.
So what does this all mean. Caps can be adventagious but not by much in the mobile environment. They simply are out of place in the application. A battery on the other hand is not.
To answer your question after all this, Adding another battery and caps is not likely going to help you. If you want your lights to not dim, put a cap on them becuase it isn't going to help much if its on your amplifers. Your best bet is to start with a good batterty that hold a lot of power, has low internal ESR and can release a ton of power quickly. Optimas are certainly a good choice. The red top is the better choice unless you listen to the system with the car off alot. Depending on the size of your alternator a higher output one might help. However, it will only be usefull if your battery actualy can't sustain the system during dips. That will be obvious if it doesn't seem to charge and starting becomes an issue. Also a rewound alternator will not help you at idle, they are ment to put out more power, but require higher RPMs to do so. I would give a new battery a whirl, and perhaps add a Battcap if things still seem iffy. Then go for the expense of a new alternator.
