Capacitors

[bubbagumper6 5,000+ posts]

So most the time when ppl are giving 14.4v rms ratings it's pretty pointless bcuz unless you run a system of batteries on a set 16v system or whatever you really will only see those 14v till u turn it up and about a half minute after you'll be sitting on the batterieS resting voltage of 12.7v?

No. Anyone who purposely allows their system voltage to fall consistently like that does not have a good enough electrical system, period. I don't care what anyone says, if your voltage is dropping all the way to your battery resting voltage you need to beef up your electrical (i.e. alternator).

 

[VWBobby 10+ year member]

Right. There must be a positive flow of current from the alt to the battery. If the voltage is down around 13V or lower, its not charging the battery very well. You need at least 14V to do a decent job of charging a batter with a 12.7V resting voltage.

 

[i2ain2thunder 10+ year member]

So most the time when ppl are giving 14.4v rms ratings it's pretty pointless bcuz unless you run a system of batteries on a set 16v system or whatever you really will only see those 14v till u turn it up and about a half minute after you'll be sitting on the batterieS resting voltage of 12.7v?

Like they said your alternator is constantly charging adding voltage to the electrical system therefore you should maintain a higher voltage than 12v at all times, if you have a lower voltage than that you should upgrade your electrical. The alternator and battery work together to provide power its never really one or the other.

 

[bubbagumper6 5,000+ posts]

Like they said your alternator is constantly charging adding voltage to the electrical system therefore you should maintain a higher voltage than 12v at all times, if you have a lower voltage than that you should upgrade your electrical. The alternator and battery work together to provide power its never really one or the other.

In a good electrical system where the alternator can keep up with the demand all the power comes from the alt. It's been said many times in this thread already.

 

[i2ain2thunder 10+ year member]

My system runs currently off a stock alternator, I have 300 total amps off my fuses from the sub amp and speaker amp. The system stays powered relatively ok, the battery remains charged somehow off a 100amp alternator, I don't even have a full big 3 right now, because my alt is so hard to get at. I know my system is not running as powerful as I could, but I've got to think that not everything works according to the math on it. Because in theory when playing heavy bass like maybe a test tone of 40hz or so for say 30minutes, you would think my battery would start loosing charge and the alternator would be trying its arse off to keep up, however I've done this and don't seem to have a charge to discharge ratio being negative. In theory pounding hard I should be drawing at the very least over 100amps and my alternator shouldn't be able to keep up but somehow it does? I stopped trying to make perfect math of it all since somehow my system works whether it's by starving power to my amps or whatnot I don't even know. I will be getting a HO soon and my yellowtop should arrive sometime next week. I'm going to install the battery and see if I notice an audible difference, then the HO and see if I hear an audible difference. I don't think the audio will change much, but I should have a much better electrical system anyway and no longer be risking hurting my amps/alt. My 2cents

 

[i2ain2thunder 10+ year member]

In a good electrical system where the alternator can keep up with the demand all the power comes from the alt. It's been said many times in this thread already.

meh edited post reread yours. I suppose if the alt can handle it all it will all come from the alt really.

 

[bubbagumper6 5,000+ posts]

You think so? I just don't know I mean if the alt can do it all by itself why even have a battery cept for starting the car of course, i've got to think some power gets drawn at some point from the battery. But I'm no electrician and have no study in the field just common sense on the subject so your prob right, I just find it hard to believe that the battery doesn't do anything.

It's basic electronics and already been stated in this thread. Current only flows from a higher potential to a lower potential. So unless the system voltage drops past the battery resting voltage, the batteries will always be at a lower potential, thus not supplying but consuming power.

 

[bubbagumper6 5,000+ posts]

My system runs currently off a stock alternator, I have 300 total amps off my fuses from the sub amp and speaker amp. The system stays powered relatively ok, the battery remains charged somehow off a 100amp alternator, I don't even have a full big 3 right now, because my alt is so hard to get at. I know my system is not running as powerful as I could, but I've got to think that not everything works according to the math on it. Because in theory when playing heavy bass like maybe a test tone of 40hz or so for say 30minutes, you would think my battery would start loosing charge and the alternator would be trying its arse off to keep up, however I've done this and don't seem to have a charge to discharge ratio being negative. In theory pounding hard I should be drawing at the very least over 100amps and my alternator shouldn't be able to keep up but somehow it does? I stopped trying to make perfect math of it all since somehow my system works whether it's by starving power to my amps or whatnot I don't even know. I will be getting a HO soon and my yellowtop should arrive sometime next week. I'm going to install the battery and see if I notice an audible difference, then the HO and see if I hear an audible difference. I don't think the audio will change much, but I should have a much better electrical system anyway and no longer be risking hurting my amps/alt. My 2cents

If you played a 40hz test tone at full tilt for 30 minutes you'd break something. Music is much, much different then test tones. Music has highs and lows in current draw and in those low parts the alternator works to recharge the batteries.

 

[bubbagumper6 5,000+ posts]

You think so? I just don't know I mean if the alt can do it all by itself why even have a battery cept for starting the car of course, i've got to think some power gets drawn at some point from the battery. But I'm no electrician and have no study in the field just common sense on the subject so your prob right, I just find it hard to believe that the battery doesn't do anything.

Read, then re-read this.

It's the same principle as capacitors, only worse with batteries. ALL CURRENT IS DRAWN FROM THE HIGHEST SOURCE OF POTENTIAL in a parallel circuit. Since the alternator is charging everything else, it is the highest source of potential. Nothing could ever be higher than it, and only a capacitor can be AS high as it. A battery will charge up to around 12.8 - 12.9. It will float higher than that. Measuring your battery right after shutting off the engine or taking it off of the charger, you will see a voltage in the 13's. Now, give your stereo one solid burp. It doesn't have to be all the way up. Just something to draw a little current. Now measure again.Just a few amps drawn, will take that float charge away (so will just sitting for 24 hrs) as it's just a tiny charge above the resting voltage. You will now see that you're around 12.8v. This is because that's actually the maximum the battery can charge up to. Since that's it's voltage, the source voltage has to drop below this for the battery to begin discharging. So, until the voltage drops that low, the battery is charging. This makes it a parasitic drain on the alternator at all times until it discharges. For this reason, a battery cannot cure voltage drop unless your old battery was just bad and had an excessive parasitic drain. ALL battery banks do is hold the voltage above 12v. They are there to protect your amplifier from being exposed voltage drops where your alternator cannot meet the demand.

 

[09civic 5,000+ posts]

the only way i see it as useful is to read your volts...

 

[ahole-ic]

Also a side question.. Is it true each battery u add gives u .2 more volts to your resting voltage?

lol no.

 

[i2ain2thunder 10+ year member]

LOL u called me out on the post when I was editing it.

 

---------- Post added at 01:22 PM ---------- Previous post was at 01:21 PM ----------

 

If you played a 40hz test tone at full tilt for 30 minutes you'd break something. Music is much, much different then test tones. Music has highs and lows in current draw and in those low parts the alternator works to recharge the batteries.

But I just mentioned I have done this...nothing broke. Explain Electric masters lol cuz I can't

 

[i2ain2thunder 10+ year member]

Not only did I not break anything but the battery was fully charged still...engine was running car was not off fyi. But still I couldn't believe it, maybe the 105amps my alt is rated at is underrated, or maybe the 3600watt rms sub amp and 800watt speaker amp is reallllllly underrated? idk

 

[ahole-ic]

the only way i see it as useful is to read your volts...

genius in the room.

 

[ahole-ic]

Not only did I not break anything but the battery was fully charged still...engine was running car was not off fyi. But still I couldn't believe it, maybe the 105amps my alt is rated at is underrated, or maybe the 3600watt rms sub amp and 800watt speaker amp is reallllllly underrated? idk

Or maybe you had crazy impedence rise during this prolonged burp and your amp was only putting out a couple hundred watts. I personally don't believe you did this, because nobody wastes the fuel to let their car idle for 30 minutes. Who has the time? If you were at your house, so you could go in and kill the time you would have gotten the cops called. IF someone were to do this experiment, they would document it. They would take voltage readings. They would have had some purpose to do it other than trying to ruin their equipment. It just doesn't add up. I know you'll come back and defend that and think I'm attacking you. I'm not, but I don't at all believe you.... and neither does anyone else brah.