[Justin7]

Hi I recently bought a 2011 Silverado and I found out about the variable charging system system in this truck where the alternator will push my battery all the way to 15.5 volts (mine only goes to 15.3) if certain conditions are met (such as battery temperature below 0 degrees).

Now I just put an amp and some nice new speakers in my doors, the only problem is that when my battery voltage is over 15 (which it is every morning for about half hour till my truck warms up) my speakers clip at even the lowest volume. Is there any way I can regulate the voltage? I really don’t want to mess with the trucks electrical too much because I know it’s complicated. But even something inline on the amp power wire?

Thanks.

TLDR; how can I regulate the battery voltage when the alternator goes into charge mode pushing it to 15.x volts?

 

[RayVoy]

Well first, I'm surprised the new system does have a built in regulator!!!!

However, any good audio supply shop should sell regulators that maintain 14v when the alt is running higher

 

[Justin7]

You’re surprised they have regulators?
I thought that was a pretty essential part of the alternator lol.

And really, I didn’t think an audio shop would have anything like that. But I’ll definitely go check. I live an hour away from the closest store so I didn’t bother checking first.

Thank you very much!

 

[Justin7]

Just went to the audio store and the guys there said they have nothing that can regulate the voltage to a constant number.

Except I think he said something about a step down.... something something. But it would only work for low amperage anyways.

So i guess I’m back to is there anyways to stop the alternator from going into charge mode?

 

[RayVoy]

You’re surprised they have regulators?
I thought that was a pretty essential part of the alternator lol.

And really, I didn’t think an audio shop would have anything like that. But I’ll definitely go check. I live an hour away from the closest store so I didn’t bother checking first.

Thank you very much!

I said I'm surprised your new equipment does not have a regulator, a built in regulator.

Your not looking for a unit that outputs a constant voltage. You need a unit that outputs battery voltage; but limits the output to 14 volts.

 

[Justin7]

Oh, I thought you meant the alt. My bad.

Also my equipment isn’t new.

And yeah I know I need to limit the voltage. I just didn’t type it out properly... I fully understand what’s happening and what I need the voltage to do for the system to work properly.

I just need to know if and how I can do it.

 

[silverado002]

A heavy duty 12 volt Zener diode connected from the power lead to ground will drop the voltage to 12 volts constant but may require a heat sink.

 

[Justin7]

Cool, I’ll look into it. Thanks Silverado002.

 

[RayVoy]

Oh, I thought you meant the alt. My bad.

Also my equipment isn’t new.

And yeah I know I need to limit the voltage. I just didn’t type it out properly... I fully understand what’s happening and what I need the voltage to do for the system to work properly.

I just need to know if and how I can do it.

OK, what I am trying to tell you, is that you can buy a unit that will provide what your looking for.

Something like this, I'm not saying this is the unit to buy, I'm just saying something like this:

https://www.amazon.ca/Yeeco-Waterpr...226&sr=8-5&keywords=12+volt+voltage+regulator

Silver, I'm with you, a diode would cover his requirements, and it should have a heat sink.
I'd put it into a box and make sure it wasn't going to short out.

 

[Justin7]

OK, what I am trying to tell you, is that you can buy a unit that will provide what your looking for.

Something like this, I'm not saying this is the unit to buy, I'm just saying something like this:

https://www.amazon.ca/Yeeco-Waterproof-Current-Converter-Regulator/dp/B00WJV1X18/ref=sr_1_5?ie=UTF8&qid=1518473226&sr=8-5&keywords=12 volt voltage regulator

Silver, I'm with you, a diode would cover his requirements, and it should have a heat sink.
I'd put it into a box and make sure it wasn't going to short out.

Wonderful, could you show me where this unit exists...? A unit that will take a variable input voltage of 11-16volts, provide a constant output voltage of 12, 13, or 14volts and won’t melt when I draw 250 amps. I can’t seem to find anything.

 

[xPosTech]

A silicon controlled rectifier will drop the voltage 1.6 volts when forward biased. Sounds like you don't need more than that. Just apply a constant gate voltage so it's conducting all the time. And yes to dissipate that kind of current it too will need a heat sink. A 600 volt 400 amp SCR ought to do the trick the old brute force way. No regulation needed.

Ted

 

[Justin7]

A silicon controlled rectifier will drop the voltage 1.6 volts when forward biased. Sounds like you don't need more than that. Just apply a constant gate voltage so it's conducting all the time. And yes to dissipate that kind of current it too will need a heat sink. A 600 volt 400 amp SCR ought to do the trick the old brute force way. No regulation needed.

Ted

I don’t know anything about SCRs. So Ill have to study up on it. I just want to make sure I got this right before I spend my night reading about them lol. It has the potential to drop the voltage ONLY when’s it’s over 15v?
(You said “when forward biased” and I can only guess that that means when the voltage is high)?

 

[j cat]

so you have a high powered audio amp.. most times the power to amp will have voltage drops . what is the voltage at amp and what is the voltage at the alternator output cable with meter ?

for a short time 15volts will happen @O F.. turn amp on after it warms up when that cold ..
I would also install a large capacitor to smooth out the power surges created by the amp..
also have a back up alternator ready to install as these will die quickly .. may require bigger alternator.

 

[Justin7]

so you have a high powered audio amp.. most times the power to amp will have voltage drops . what is the voltage at amp and what is the voltage at the alternator output cable with meter ?

for a short time 15volts will happen @O F.. turn amp on after it warms up when that cold ..
I would also install a large capacitor to smooth out the power surges created by the amp..
also have a back up alternator ready to install as these will die quickly .. may require bigger alternator.

I don’t think I need a cap or a new alternator. There’s almost no voltage drop. My headlights don’t even dim.

And I’m not sure what you mean by
“for a short time 15volts will happen @O F”
What’s O F?

 

[xPosTech]

0 F is zero degrees Fahrenheit. The SCR would conduct all the time dropping the voltage 1.6 V. It's value is simplicity. Used this way it's just a diode drop.

Ted

 

[j cat]

0 F is zero degrees Fahrenheit. The SCR would conduct all the time dropping the voltage 1.6 V. It's value is simplicity. Used this way it's just a diode drop.

Ted

I am familiar with scr diodes .. with the power amp load//amps he may need a very large one and mounted on a aluminum heat sink.. my question is what is the amps power output RMS watts .. that will reveal the amps required and the wiring ,.
very possible the amp does not like low temps .. amp cutout could be a speaker coil cooked ... see that a few times family members cars with this type stuff... spk coils will do it ..then ka boom ...

the problem with a voltage dropping component when the alternator shuts down , perhaps it never will with the amp on loading up the electrical system ..

 

[Flyinfool]

You need to do some testing.
Connect a volt meter across the power input to the amp, watch the voltage as it warms up to see at what voltage the clipping stops, Now you will know what voltage you need to drop to. There are many ways to drop voltage, but with out knowing what is needed we can only guess at numbers and methods.