[zeptoplix]

Okay for those of you who do not know, my current stereo setup consists of 2 1000bd amplifiers one JBL50x4watt amp, no powercaps and lately I've been encountering some odd voltage spikes.

Sometimes when i crank the system up the voltage drops obviously like its supposed but then sometimes right after a hard bass hit the voltage will spike at like 15.3 or even high enough to shut the amps off.

I have a Bell radar dector that has a voltage meter on it, I was originally concerned about its accuracy but when it beeped high voltage and the system shut down I realized I have a problem on my hands that im unsure of how to solve. Im not sure if this is Car Audio related or maintenance related... since it has to do with both issues pretty much

Thanks for any help.

 

[hoss]

what kind of amps are they(just the sub amps, the 4 channel shouldnt be a factor)? how big is the power wire running to the amps? how high are your gains set at?

this sounds like its caused by the stereo, ince it happens when the stereo works real hard. this info might help to troubleshoot though.

 

[chococat1079]

Sound like your car is doing what it is supposed to do. That's your voltage regulator working. When it senses that there is more load on the electrical system, it starts producing more voltage to compensate for the voltage drop. Unfortunately, it does it slower than you would like it to and causes a voltage spike of around 15V. My suggestion is for you to get a 1 farad capacitor or maybe two. You should really try to do a current draw test on your system to see how much current you are really pulling. I think your 1000d amp will pull around 60 amps at full output. Take two of those and add a 4 channel amp...you are going to pull some serious current. A 1 farad cap and a higher output alternator would be your best solution. If you have questions...ask away!~!

 

[hoss]

high output alt, avoid a cap like the plaugue. especially a small one like a 1 farad

 

[mth676]

why avoid a cap. I have a 6 farad and it works great along with a deep cycle battery in the trunk. And i dont get those power surges even while using about 3000 watts.

 

[chococat1079]

Caps are great if you have a need for them. In this case, I would recommend it because of the voltage spikes. Remember, a capacitor acts like a line conditioner. It helps smooth out those voltage irregularities and provides extra voltage for a short amount of time. That's why I said that you should go with a higher output alternator AND a capacitor. Oh yeah...if you go to a electrical supply warehouse for contractors, you can find a 1 farad capacitor for around $35 US dollars. Sure, it's not going to look pretty like the ones that you buy at the audio store, but it will do the EXACT same thing. A capacitor is a capacitor. Hope that helps.

 

[hoss]

caps dont act like a line conditioner, they act like a band aid. this has been coverend in this forum several times, if you do a search you can find a more detailed description of what i am talking about.

what it basically boils down to is that a cap simply cannot re-charge quickly enough to be useful in car stereo. they are meant to drain themselves within a fraction of a second, once they drain, they present an extra load to the charging system. if you have any bass that hits for more than a fraction of a second then the cap will be an extra load since it will be trying to charge and discharge at the same time. if you get a higher output alt, or even just get your alt re-wound to put out a higher voltage, that should take care of any excessive currrent draw problems.

 

[chococat1079]

Hoss, your point is well taken, but I will have to argue that a cap used in tandem with a higher output alternator will be the best solution. You and I answered the question. Yes, a capacitor discharges very quickly, but a vehicle's charging system cannot react as quickly as a capacitor. Yes, it's going to put a load on the charging system of the car(the capacitor), but that's better than draining your battery. Your alternator's purpose is to supply ALL of the vehicle's electrical needs when the car is RUNNING. When your alternator cannot supply enough current and voltage at full-field, then the current and voltage is drawn elsewhere, mainly the battery. The battery is not a device that likes to be charged multiple times in a short amount of time. It heats up and produces hydrogen gas....blah blah blah, you know the deal. That's why it is better to run a capacitor ALONG with a higher output alternator for the best results. Oh yeah, the capacitor charges pretty quickly and isn't a real strain on a upgraded charging system.

*edit* If any one of you guys gets a chance, run a charging test with a low res scope and you will see why I say to use both. They both have their shortcomings. That's why they need to be used together.

 

[zeptoplix]

No you guys are wrong. I solved the problem, but didn't bother posting a follow up since the thread was dead. I was talking to a mechanic about the problem and he told me the alternator was probably going. And that was the problem. I am sorry but a surge of 15.5v or greater is not normal. Anything powerful enough to shut down and amp is bad. ok. And I am running two batterys, I have deep charge battery as well as my normal one.