will my alternator survive??? please advise, i know nothing

[xoch1 10+ year member]

I have a 2000 civic. I am currently running a bridged Total Mobile Audio amp to 2 12 in subs. 360 watts rms. Sounds good and now I want to add a 4 channel to the setup. I am trying to avoid running into problems with my alternator and low power issues. My stock alternator is 70 amp I believe. The amp I want to buy is a MB Quart DSC 480. I will be running it in 4 ohm so the total wattage from that amp would be 320 watts rms. So this should total 680 watts. I am assuming it might be slightly less then that due to efficiency issues. So do you think my alternator will be safe at 680 watts rms or less? I don’t have anymore money to shell out so if it is going to kill my stock alt, I might just say heck with it and continue to run the highs off the deck. What do you all think?

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[jbizzle 5,000+ posts]

Check your voltage drop.

 

[sexy 10+ year member]

please read this SIGNAL TO NOISE: MAY/JUNE 2000 i posted this because i just know there will be a bunch of stupid coments about how you should buy more batteries read it a couple of times just to be safe. if you realy want to know for sure what amount of curent draw you have now find somone who has one of these amp probes Amazon.com: AC/DC Clamp-On Current Probe - 1000 Amp: Automotive any good car audio shop should have one and lots of electrians have one. clamp it onto the positive wire on the battery start the car turn on the headlight,and heater and then your audio system turn it up to the high end of what you like for playing music with some bass. this will tell you how many amps you are drawing from the alternator. this number is what will tell you if you are maxing out the alternator to the point of causing harm. another way is to see your voltage drop with a voltmeter now from experience i can tell you that if you dont have enough power to run your audio system like lets say you are droping down to 9 or 10 volts and staying there then that means your alt is not keeping up but you may burn up the audio amp a lot sooner than the alternator. go back and read that link i posted first . there are ways to calculate your curent usage too but it is just a calculation the voltmeter or amp clamp is for sure. go back and read the first link again.

 

[xoch1 10+ year member]

Im going out in a little bit to check it with a dmm. Im not sure what i am looking for but will report back my findings. Does anyone know about how many amps does a MB Quart DSC480 draw?

 

[xoch1 10+ year member]

Ok here is what I got. Idle with nothing on I got 14.28.......... Idle with music as loud as I normally listen and headlights and ac running I got

12.6....... at 2000 rpms I got 13.85 with all that stuff running. So what do you all think?

 

[helotaxi 5,000+ posts]

please read this SIGNAL TO NOISE: MAY/JUNE 2000 i posted this because i just know there will be a bunch of stupid coments about how you should buy more batteries read it a couple of times just to be safe. if you realy want to know for sure what amount of curent draw you have now find somone who has one of these amp probes Amazon.com: AC/DC Clamp-On Current Probe - 1000 Amp: Automotive any good car audio shop should have one and lots of electrians have one. clamp it onto the positive wire on the battery start the car turn on the headlight,and heater and then your audio system turn it up to the high end of what you like for playing music with some bass. this will tell you how many amps you are drawing from the alternator. this number is what will tell you if you are maxing out the alternator to the point of causing harm. another way is to see your voltage drop with a voltmeter now from experience i can tell you that if you dont have enough power to run your audio system like lets say you are droping down to 9 or 10 volts and staying there then that means your alt is not keeping up but you may burn up the audio amp a lot sooner than the alternator. go back and read that link i posted first . there are ways to calculate your curent usage too but it is just a calculation the voltmeter or amp clamp is for sure. go back and read the first link again.

The article in that link has obviously been around for a long time but it is really a half truth. It takes the current drain to an extreme and depicts it as continuous. It also is using a tiny motor that gets tired to turn things as opposed to a car engine. The cyclist cannot keep up to begin with, that is not because the alternator was tapped out it was because the engine was. Once the battery went into discharge the guy is fighting a losing battle. A battery that is partially discharged is a load until it is recharged. If the alt never recharges it, it becomes more of a load as it discharges further. If this "experiment" had some more horsepower on tap to turn the alt, the result would 1) be more representative of reality and 2) be completely different in that the battery would never go into discharge with that paltry amount of discharge.

This isn't an accurate representation of what happens with your car unless your average draw (music isn't hardly continuous and doesn't hardly present a constant high demand on the electrical system unless you only play "music" with long droning bass notes) accounting for the peaks and valleys in demand exceed the output capability of the alt. In reality the battery discharges very slightly with a heavy transient, mostly because the alt cannot respond fast enough, and recharges almost as quickly in the time between transients. An extra battery works in the same way as the pressure tank on an air compressor. Try running an air tool with a high peak but low average demand for air, like a nail gun, on a compressor without a tank. It won't work worth a **** and to a point, the bigger the tank the better it will perform. Your car's electrical system is the same way. To a point the bigger a current reservoir the system has to draw from the better it will handle peaks. The problem comes when you get the reservoir too big and the alternator gets well behind in keeping the reserve filled. Adding a single battery isn't going to hurt anything and will help stabilize the voltage for a system that needs to deal with transient demand spikes but does not have a high average demand. If you are getting to a point where the average current demand is exceeding the capability of the alt to keep the battery recharged, its time to upgrade the alt.

600ish watts is a very modest system and the average current draw will be within the capacity of the alt to handle under normal conditions. Where you might run into problems is with the headlights on, the AC on and the music cranked. If it is really a concern, I would find a Class D amp to run the subs to minimize the current draw there and move your current sub amp to the front speakers, continuing to run the rears off the deck.

As far as David Navone and Richard Clark, they have also published articles that try to claim that grounding to the battery is bad by using what amount to a current detector to portray the battery post as a noisy ground when in reality it only showed that a lot of current flowed there. Their articles are perfect examples of a little information being a dangerous thing. I don't know if they actually believe what they say or if they are just trying to make themselves look more knowledeable or what, but they have propagated some completely false information over the years hidden behind a thin veil of fact and actual science.

 

[Asystole 10+ year member]

please read this SIGNAL TO NOISE: MAY/JUNE 2000 i posted this because i just know there will be a bunch of stupid coments about how you should buy more batteries read it a couple of times just to be safe. if you realy want to know for sure what amount of curent draw you have now find somone who has one of these amp probes Amazon.com: AC/DC Clamp-On Current Probe - 1000 Amp: Automotive any good car audio shop should have one and lots of electrians have one. clamp it onto the positive wire on the battery start the car turn on the headlight,and heater and then your audio system turn it up to the high end of what you like for playing music with some bass. this will tell you how many amps you are drawing from the alternator. this number is what will tell you if you are maxing out the alternator to the point of causing harm. another way is to see your voltage drop with a voltmeter now from experience i can tell you that if you dont have enough power to run your audio system like lets say you are droping down to 9 or 10 volts and staying there then that means your alt is not keeping up but you may burn up the audio amp a lot sooner than the alternator. go back and read that link i posted first . there are ways to calculate your curent usage too but it is just a calculation the voltmeter or amp clamp is for sure. go back and read the first link again.

I suggest you go out and actually test the things you say.

Seriously, go find a car with a stock amp, measure the voltage drops with one battery and then with two.

You'll find that your precious little link that you spam all around here is nothing but dumb.

 

[sexy 10+ year member]

The article in that link has obviously been around for a long time but it is really a half truth. It takes the current drain to an extreme and depicts it as continuous. It also is using a tiny motor that gets tired to turn things as opposed to a car engine. The cyclist cannot keep up to begin with, that is not because the alternator was tapped out it was because the engine was. Once the battery went into discharge the guy is fighting a losing battle. A battery that is partially discharged is a load until it is recharged. If the alt never recharges it, it becomes more of a load as it discharges further. If this "experiment" had some more horsepower on tap to turn the alt, the result would 1) be more representative of reality and 2) be completely different in that the battery would never go into discharge with that paltry amount of discharge.
This isn't an accurate representation of what happens with your car unless your average draw (music isn't hardly continuous and doesn't hardly present a constant high demand on the electrical system unless you only play "music" with long droning bass notes) accounting for the peaks and valleys in demand exceed the output capability of the alt. In reality the battery discharges very slightly with a heavy transient, mostly because the alt cannot respond fast enough, and recharges almost as quickly in the time between transients. An extra battery works in the same way as the pressure tank on an air compressor. Try running an air tool with a high peak but low average demand for air, like a nail gun, on a compressor without a tank. It won't work worth a **** and to a point, the bigger the tank the better it will perform. Your car's electrical system is the same way. To a point the bigger a current reservoir the system has to draw from the better it will handle peaks. The problem comes when you get the reservoir too big and the alternator gets well behind in keeping the reserve filled. Adding a single battery isn't going to hurt anything and will help stabilize the voltage for a system that needs to deal with transient demand spikes but does not have a high average demand. If you are getting to a point where the average current demand is exceeding the capability of the alt to keep the battery recharged, its time to upgrade the alt.

600ish watts is a very modest system and the average current draw will be within the capacity of the alt to handle under normal conditions. Where you might run into problems is with the headlights on, the AC on and the music cranked. If it is really a concern, I would find a Class D amp to run the subs to minimize the current draw there and move your current sub amp to the front speakers, continuing to run the rears off the deck.

As far as David Navone and Richard Clark, they have also published articles that try to claim that grounding to the battery is bad by using what amount to a current detector to portray the battery post as a noisy ground when in reality it only showed that a lot of current flowed there. Their articles are perfect examples of a little information being a dangerous thing. I don't know if they actually believe what they say or if they are just trying to make themselves look more knowledeable or what, but they have propagated some completely false information over the years hidden behind a thin veil of fact and actual science.

In your examples of why and how things work you have been giving out theory based on very modest audio systems you said so yourself 600ish watts. In the threads where I have posted this link about the bicycle people are asking about much higher usage systems with little alternator output to back them up. Everything you said is correct 100% in the realm of low power applications. Now let’s talk about what is happening in today’s car audio market there are some inexpensive amps like ap3000s out there that can be had for around $350. These easily affordable amps are also extremely inefficient so just one of these power hogs can easily exceed the output of a small alternator. Car audio has changed so much in the last 10 years just because of these power hungry amps and their affordability. I have read enough post that you have made to recognize the fact that you are in the top one percent of people who understand electrical theory. So what should the answer be when people are asking for electrical help and they are using more power than their alt can produce and we both know that more batteries is not the answer because people do ride around listening to heavy bass for long periods of time. I don’t have tons of spare time on my hands to address this problem I wish I did that’s why I have been posting that bicycle link. Maybe I will make a thread explaining this in a better way at some point in time or maybe you have some extra time to do it from what ive seen you could prolly do it better than me anyways for sure.

 

[The Silverman 10+ year member]

1. Check voltage

2. Do Big Three

(I doubt you have to go much further than this)

3. Check Voltage

4. Replace Battery

 

[helotaxi 5,000+ posts]

In your examples of why and how things work you have been giving out theory based on very modest audio systems you said so yourself 600ish watts. In the threads where I have posted this link about the bicycle people are asking about much higher usage systems with little alternator output to back them up. Everything you said is correct 100% in the realm of low power applications. Now let’s talk about what is happening in today’s car audio market there are some inexpensive amps like ap3000s out there that can be had for around $350. These easily affordable amps are also extremely inefficient so just one of these power hogs can easily exceed the output of a small alternator. Car audio has changed so much in the last 10 years just because of these power hungry amps and their affordability. I have read enough post that you have made to recognize the fact that you are in the top one percent of people who understand electrical theory. So what should the answer be when people are asking for electrical help and they are using more power than their alt can produce and we both know that more batteries is not the answer because people do ride around listening to heavy bass for long periods of time. I don’t have tons of spare time on my hands to address this problem I wish I did that’s why I have been posting that bicycle link. Maybe I will make a thread explaining this in a better way at some point in time or maybe you have some extra time to do it from what ive seen you could prolly do it better than me anyways for sure.

You obviously didn't read my post. You also clearly didn't apply it to the context of the thread. The OP asked about a 600W system. That is where the reference in my post came from. I fully understand what is required to run a big system. You clearly fail to understand the utter fail represented by that article and how it "demonstrated" nothing. If you had read my post I clearly pointed out that average current consumption is what matters. As long as the alt can handle that, adding a single battery can help keep the alt alive and stabilize the voltage. Going straight to an upgraded alternator isn't the right answer most of the time and definitely not the answer for the OP.

Yes there are some real current hogs out there. I've got one that is more than 15 years old, in fact. The reality is that most people aren't using amps like that. Most of those that are know, or quickly realize that they need some electrical upgrades to support such an amp. These big *** amps are only "mainstream" on the forums, not in the rest (read majority) of the car audio aftermarket.

The problem with posting the bicycle link is that it promulgates bad information based on pseudo-science and takes a little piece of theory, misapplies it and passes it off as the truth. There are too many myths, half-truths and outright lies that are accepted as fact in the car audio community for those that know better to continue to encourage more.

 

[sexy 10+ year member]

You obviously didn't read my post. You also clearly didn't apply it to the context of the thread. The OP asked about a 600W system. That is where the reference in my post came from. I fully understand what is required to run a big system. You clearly fail to understand the utter fail represented by that article and how it "demonstrated" nothing. If you had read my post I clearly pointed out that average current consumption is what matters. As long as the alt can handle that, adding a single battery can help keep the alt alive and stabilize the voltage. Going straight to an upgraded alternator isn't the right answer most of the time and definitely not the answer for the OP.
Yes there are some real current hogs out there. I've got one that is more than 15 years old, in fact. The reality is that most people aren't using amps like that. Most of those that are know, or quickly realize that they need some electrical upgrades to support such an amp. These big *** amps are only "mainstream" on the forums, not in the rest (read majority) of the car audio aftermarket.

The problem with posting the bicycle link is that it promulgates bad information based on pseudo-science and takes a little piece of theory, misapplies it and passes it off as the truth. There are too many myths, half-truths and outright lies that are accepted as fact in the car audio community for those that know better to continue to encourage more.

your right this thread was not one where the op was runing tons of power i dont know why i did not notice that. i do notice lots of threads where there is an isue with too much power for the alternator being used. I think your right about the bicycle link being a poor example and i will stop using it. there are just way too many threads where people suggest adding batteries to a system that is already way underpowered from the alternator.

 

[audiolife 5,000+ posts]

Isn't a big alternator harder to turn for the engine? Isn't two or three alts harder to turn than just one? That poor engine is going to be havingh to work much harder to cover the load so my solution is do not run anything over 300 watts. and get more efficient head lights yano those curly q type that save engery.

 

[helotaxi 5,000+ posts]

Take out the air conditioner while you're at it. That makes the engine work harder, too. Same for the transmission and wheels...

 

[CHEMMINS 10+ year member]

lawlz

 

[audiolife 5,000+ posts]

Take out the air conditioner while you're at it. That makes the engine work harder, too. Same for the transmission and wheels...

//content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gifHope you sensed my sarcasm