help capacitor

[Ninesvnsicks 10+ year member]

you can figure it all out by asking yourself, what exactly is dimming? then asking yourself, what voltage does my battery begin to discharge at? once you honestly answer those questions youll realize batteries cannot fix dimming

Dimming means the lights dim and mine do not voltage is not dropping I'm not saying others don't dim but as of right now mine do not.

 

[05fronty 5,000+ posts]

umm i have no voltage drop running a aq 2200 and a autotek 125.2. stock 110 amp alt and 4 75 amp ups batts.

 

[Ninesvnsicks 10+ year member]

umm i have no voltage drop running a aq 2200 and a autotek 125.2. stock 110 amp alt and 4 75 amp ups batts.

wow 4 batteries you running anything else?

 

[05fronty 5,000+ posts]

wow 4 batteries you running anything else?

well the big 3 also. cheap wally world batt up front.

 

[LosIsATool 5,000+ posts]

depends on the car.. I had bad drop with 1 1500 and a group 51 YT in the back. Big 3 and a group 34 YT up front with a run of 1/0..

 

[Ninesvnsicks 10+ year member]

I have yellowtop and xs power d5100 under my hood //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[ahole-ic]

So what you all are saying is, your batteries hold the same voltage as your alternators put out, and discharge at this voltage as well?

 

[Ninesvnsicks 10+ year member]

So what you all are saying is, your batteries hold the same voltage as your alternators put out, and discharge at this voltage as well?

They are deep cycles so they have reserve seems to keep up so far.

 

[ahole-ic]

They are deep cycles so they have reserve seems to keep up so far.

No try to pay attention. I am specifically asking you about voltage. Do your batteries hold the same voltage that your alternator charges at, and discharge at this voltage as well?

 

[hispls 5,000+ posts]

No try to pay attention. I am specifically asking you about voltage. Do your batteries hold the same voltage that your alternator charges at, and discharge at this voltage as well?

Batteries generally charge 2V over their resting voltage. OF course an alternator won't instantly deliver current either, there's a bit of a lag so in truth neither will necessarily solve "light dimming" If the fact your headlights are dimming really bothers someone, they can put capacitors on their headlights.

If the question is "what electrical system upgrades will I need to run 1400W amp safely". The answer would be either a high output alternator or an additional battery. Both would be better, but probably overkill IMO.

 

[wenn_du_weinst 10+ year member]

capacitors have a use....

 

[hispls 5,000+ posts]

capacitors have a use....

Are they going to help OP properly power his amp?

 

[ahole-ic]

Batteries generally charge 2V over their resting voltage.

Exactly. They don't have much charge above their resting voltage. Since that is the exact same drop in voltage the headlights are seeing and causing them to dim, batteries cannot fix it.

OF course an alternator won't instantly deliver current either

Well that isn't really true. It takes the regulator a second to sense a voltage drop and raise the voltage up which is what you're referring to, but nice alternators don't have much of that. For instance my dc power 270sp can power ~3000 wrms clamped from my amp with no battery in the back with no voltage drop. It holds steady the entire time.

, there's a bit of a lag so in truth neither will necessarily solve "light dimming" If the fact your headlights are dimming really bothers someone, they can put capacitors on their headlights.

lol

If the question is "what electrical system upgrades will I need to run 1400W amp safely". The answer would be either a high output alternator or an additional battery. Both would be better, but probably overkill IMO.

I know the OP said he already did the big 3 but that is usually the best option, and doing a negative run in addition to their chassis ground. Then making sure their chassis ground is as good as it possibly can be.

 

[hispls 5,000+ posts]

And MSRP on an alternator that'll really do that is probably going to be around or greater than 500$. A good deep cycle can be had for 150$ (give or take) which will adequately feed his amp.

Chasis ground is about the most under-rated part of electrical system.

 

[Kangaroux 5,000+ posts]

Since we seem to have this argument on what appears to be a regular basis let me try and clear a few things up...

Capacitors that are used to try and maintain voltage are relatively useless. The reason behind this is that their storage capacity is so small that when a long bass line comes in and the capacitor discharges to make up for the voltage drop, it has to recharge while the bass line is still playing because the discharge rate is so quick. This, in turn, causes even greater drop because now the capacitor and the amplifier are pulling current. The only use for a capacitor (besides the obvious use of being on a circuit board) is when you need a quick discharge of energy, they are not good for long periods of time because they simply don't have the reserve.

Batteries make up for the poor reserve size of capacitors and are why people favor them over capacitors. However the argument is that even with a battery you will still get voltage drop. And that's true, because a battery is not a fix for voltage drop. A battery, if anything, is just a bandaid fix to make up for the fact that your alternator can't keep up. So if your voltage is dropping way down, all adding a battery will do is provide an extra power source for when your alternator can't charge. This still causes voltage drop, because the battery does not rest at the alternator's charging voltage, it rests at around 12.8. So if your voltage was dropping down to 12.0v, it may only drop down to 12.8 because of the extra battery. If anything, this is good because it prevents too low of a voltage. You may not be able to fight voltage drop with a battery, but you can at least attempt to sustain it at a reasonable level. But then the problem you run into is your alternator was not designed for having to charge an extra battery, so you put a lot more stress onto it. Depending on the conditions (such as typical listening volume, or current draw), the extra stress isn't usually too great, so we can get away with that.

Lastly, obviously you have the alternator which doesn't really have a downside to it besides price I guess. But basically, every argument ends in the fact that a new alternator is the best choice, which you can't argue as being false. However, taking into consideration the conditions of most peoples systems, a new alternator simply isn't necessary. The OP is running a 1400w amp, which on a 12v system is drawing roughly 110A of current. His vehicle most likely has a 80-90A alt, so to dish out the hundreds of dollars for the extra couple dozen amps of available current output just really isn't that needed. It would solve the problems he's experiencing, but realistically speaking, if you were in his shoes I highly doubt you would drop the $ on a new alt when a battery would more than likely take care of the problems he is having.

Moral of the story: Using a cap to prevent dimming is an improper use for it, batteries won't prevent voltage drop but can sustain voltage at a reasonable level, and an alt would be the ideal thing to upgrade, but in most cases it is an unneeded expense.

/poast