Installing a Second Battery

I am looking at installing a second battery in my trunk to run my system off of. I know it can be done I just don't know how to do it. So has anyone done this and if so how?

[leroBob]

Have u ever thought of just buying a capaciter it'll save time and aggravation a whole lot easier two what do you plan on running?

I currently have (1) 12 inch Kicker Solo Baric, (2) Boston Acoustic 5 1/4 with tweets, and (2) Boston Acoustic 3-way 6x9. I Have a 750 watt Kicker amp pushing the 12, two 200 watt amps. One pushing the 3 ways, one the componets. Right now I have one of the Interstate dry cell's and it works fine. But have plans of adding some interior neons and don't want to put to much to that one battery.

[Cyber Knight]

Neons hardly draw any juice, I agree that a capacitor would be the way to go.

How much are we looking at for a capacitor? I already have an extra battery, so that is why I was looking at that route.

[Cyber Knight]

Probably around $100/Farad, I don't think you'd need much more that that. There is good info here on what capacitors do and how to pick one, of course this company says theirs is the best, but it might help you. Installing a capacitor would be easier, and cleaner, but you already have the battery and I'm not sure how you would hook it up, but you'd need to at least connect it to your equipment and the/an alternator to keep it charged. Plus I doubt you have room under your hood, and that's a lot of extra weight (if a fast car is important to you).

[leroBob]

depends on how many farands u were looking at sounds like you will only a 1 farand capaciter depending where u buy it from 60.00 to 120.00 Capaciters would be a hell of a lot easier then a battery. :thumbsup:

i have a second battery in my trunk..they ran a ground from the battery in the front to the one in the trunk and the power from the front as well..works beautifully

DID YOU NEED A HIGHER AMP ALTERNATOR?

What gauge wire did they run?

4 gauge, and i havent changed the alternator, no problems, plus i also have a cap

Thanks

[b-spot]

caps are a waste unless your dimming

^^^ caps are not a waste they are made to make you system stay at level volumes. The way it works is when you sub hits a hard note then hits again the second one will not be as loud as the first. Basically it feeds your amp a constant power that doesnt fluctuate with every note. Caps will also give you better sound quality and a higher spl.

[b-spot]

If your running a system big enough its hitting your battery that hard, you should just get a second one

thats why i got a second one

[Screamin eagle]

I have to say that adding a second battery only effects how long you can play your system while the ignition is off, an example is at a car show. While your car is running, your stereo pulls it's juice from the alternator. When your lights dim as the bass hits, that is a sign that a capacitor is needed to help store the juice from the alternator as it cannot transfer large amounts of electricity fast enough. The second battery really has nothing to do with how much electricity goes to your system when the ignition is running.

r u on crack? my system feeds off the second battery, not the one in the engine. sure it'll help when the engine is off, but it also helps so that you dont work the alternator so much

As far as the quick-hitting bass like Redddog88 mentioned, a second battery won't help at all. As the amp needs power, it draws from the circuit...the alternator provides what it can...if that's not enough, the battery picks up the slack. So the battery says "ohhhhhhhh yooooouuuu waaaaaant moooooore powerrrrrrrr? Okaaaaaaaaayyyyy". By that time, it's too late. The cap will discharge almost instantaneously by comparison. The cap would say, "o u wnt pwr? k!" like Beavis on crappucino. Then the alternator recharges the cap (or battery) between these large power draws.

Think about it this way: you have an alternator, two batteries, a cap, and then all the power consumption devices. You still only have one power source (alt), three ways to store it (batteries and cap) and many ways to use the power (amp, lights, radio, etc.).

Adding a second battery will allow you to run your system longer with the car off, but if you have the ability to drain two batteries with your system, then as soon as you start the car, the alt has to charge two batteries instead of one. THAT's what will strain the alternator.

Screamin Eagle is mostly right...except the alternator has NO delay in providing power...it provides it no matter what, it's just a matter of what devices grab it. Theoretically, if you didn't need a cap but had one, the cap would charge and then never discharge (not accounting for leakage) because the circuit would never need more power than what was being put in by the alternator.

99BlackAlero: your system doesn't really feed off the second battery. It feeds off the entire electrical circuit, of which both batteries and the alternator are all a part. The alternator will always provide as much power as it's capable of into the circuit until more is needed, then the storage devices will dischargeto make up the difference, cap first because of less delay, then batteries. And after the discharge, the storage devices will pull current out of the circuit to replenish themselves.

[edit -- adding a bit more]
If you're concerned about not having enough power, get a bigger alternator. Pushing an alternator to 90% of it's capacity all the time is what'll make it fail. Get a big 200-amp alternator (or at least something larger than what we've got, which I think is 105-amp...not sure though) and let that run at 60% and it'll last forever. Sort of...

Adding a second battery won't hurt anything. Adding a cap will help condition the power so your amp sees consistent power...that'll help the amp's power supply last longer. Getting a bigger alternator will prevent nearly any electrical problem that a system can cause...although if you compete it may change the class you're in since there's more power available to your system. Something to keep in mind if you compete. (I don't compete, so I don't know the specific rules, but if anyone is going to upgrade the alternator check and see if it matters to them...you know.)

[Screamin eagle]

Hey I was close....... :P