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So I believe my alternator is sufficiently strong for my system. It is a 320 amp, Pure Power Alt. I can push my system to full tilt (right before clipping) and it might drop from 14.5, to say 14.2 > while sitting, and at an idle. But If I'm driving down the freeway, I can play the system at full tilt, and it won't drop even one tenth from 14.5 volts ! {which I think is pretty bad @$$ ;)}

 

But here's the thing that bugs me. With my system shut completely off, on a hot day, after Ive been driving for a while, my voltage will drop to as low as 13.6 volts :( And the thing is, I can hear a significant loss of performance from my system, when it's only getting 13.6 volts, vs. 14.5. In other words, the stereo system has little to no effect on my voltage, while a hot day has a BIG effect on my voltage ?

So I keep reading, "Oh, this is normal... and alternators do this to protect themselves from over heating, etc, etc...."  I've also read, that it might be possible to use an aftermarket regulator that pegs it at 14.5 volts, but that this can cause the alternator to fail prematurely :( So that kind of sucks. What can I do to keep my voltage at 14.5 volts ? Do I need to do some liquid cooling of that bitch ? :) lol

 

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39 minutes ago, Fish Chris said:

So I believe my alternator is sufficiently strong for my system. It is a 320 amp, Pure Power Alt. I can push my system to full tilt (right before clipping) and it might drop from 14.5, to say 14.2 > while sitting, and at an idle. But If I'm driving down the freeway, I can play the system at full tilt, and it won't drop even one tenth from 14.5 volts ! {which I think is pretty bad @$$ ;)}

 

But here's the thing that bugs me. With my system shut completely off, on a hot day, after Ive been driving for a while, my voltage will drop to as low as 13.6 volts :( And the thing is, I can hear a significant loss of performance from my system, when it's only getting 13.6 volts, vs. 14.5. In other words, the stereo system has little to no effect on my voltage, while a hot day has a BIG effect on my voltage ?

So I keep reading, "Oh, this is normal... and alternators do this to protect themselves from over heating, etc, etc...."  I've also read, that it might be possible to use an aftermarket regulator that pegs it at 14.5 volts, but that this can cause the alternator to fail prematurely :( So that kind of sucks. What can I do to keep my voltage at 14.5 volts ? Do I need to do some liquid cooling of that bitch ? :) lol

 

Unfortunately, they're right. It's normal. My mechman does it as well. The only way I know of to mitigate this is to externally regulate the alt. And yes, depending on how much "abuse" the alternator takes from heat, it can reduce the lifespan a little bit, too a lot a bit. 

One thing to add is, I've read that some vehicles will drop the alt output when hot, but once you turn on the lights, or AC fan, or some sort of particular electrical component, it'll jump back up to 14.7. I don't know if you're vehicle will do that. Just figured I'd add that little nugget. 

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That's what I figured :( And yea, if I turn on my AC (which I always do in the Sacramento Summer ;) it will jump my voltage up a few tenths, maybe from 13.6 to 13.9.... but not all the way back up to 14.5. Im seriously wondering how I can "super cool" that alternator ? Freaking wrap that bitch in a liquid cooled jacket !  :) I'm only half joking here... 

Maybe it's mostly a psychological thing here, with my hard core OCD... But I'd SO like to see 14.6 volts on my voltmeter at ALL times ! Even when beating the chit out my system on a hot Sacramento Summer day !

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Ha ! Guess what ? Apparently, it's not even a big deal, and has already been done for a long time ! 

 

https://www.google.com/search?q=water+cooled+alternator&sxsrf=ALeKk03wZ1MQJKJIhcOjMaPb2H22Rs8Okg:1620487906635&source=univ&tbm=shop&tbo=u&sa=X&ved=2ahUKEwiLpKbws7rwAhXGsZ4KHbQsCRkQ1TV6BQgBEIoB&biw=2327&bih=1180

 

What the hell Mechman ? Why can't we have this option ? I want a 600 amp, watercooled Alternator for my F150 please :) Thank you in advance :) Oh, and please put in a regulator that pegs my voltage at 14.6 ;) 

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3 hours ago, Fish Chris said:

Ha ! Guess what ? Apparently, it's not even a big deal, and has already been done for a long time ! 

 

https://www.google.com/search?q=water+cooled+alternator&sxsrf=ALeKk03wZ1MQJKJIhcOjMaPb2H22Rs8Okg:1620487906635&source=univ&tbm=shop&tbo=u&sa=X&ved=2ahUKEwiLpKbws7rwAhXGsZ4KHbQsCRkQ1TV6BQgBEIoB&biw=2327&bih=1180

 

What the hell Mechman ? Why can't we have this option ? I want a 600 amp, watercooled Alternator for my F150 please :) Thank you in advance :) Oh, and please put in a regulator that pegs my voltage at 14.6 ;) 

Why give it to mechman? There's your million dollar idea bro! 

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My build log here. Check it out! 

 

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On 5/8/2021 at 9:30 AM, Fish Chris said:

if I turn on my AC (which I always do in the Sacramento Summer ;) it will jump my voltage up a few tenths

 

Interesting. Turning on the AC in some (most?) vehicles will cause the radiator or another fan to turn on the cool the AC condenser. The added air flow under the hood would provide some extra cooling for the alternator, which would in turn increase its output if it was running in heat-protection mode. I was not aware of this effect, but it makes sense.

 

Another way that has proven effective to reduce heat in the engine compartment is exhaust wrap and turbo blanket (if your F150 has a turbo). Check out this video from Engineering Explained for more on that topic. Less heat in the engine bay = more consistent alternator output.

 

 

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I did some reading on AGM batteries and vehicle charging systems over the weekend, and I wonder if the voltage drop you're seeing on longer drives is due to your vehicle's charging system being smart enough to transition into a float stage so as not to overcharge the battery. This would actually be a good thing for the life of your battery, if not for your amplifier's performance.

 

Check out this very interesting article. It's part of a series of very interesting articles about AGM batteries, but even if your battery isn't AGM, the information on these pages is still pertinent to any lead-acid battery.

 

https://workshoppist.com/car-alternator-charge-agm-battery/

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On 5/10/2021 at 6:49 AM, clarknova said:

I did some reading on AGM batteries and vehicle charging systems over the weekend, and I wonder if the voltage drop you're seeing on longer drives is due to your vehicle's charging system being smart enough to transition into a float stage so as not to overcharge the battery. This would actually be a good thing for the life of your battery, if not for your amplifier's performance.

 

Check out this very interesting article. It's part of a series of very interesting articles about AGM batteries, but even if your battery isn't AGM, the information on these pages is still pertinent to any lead-acid battery.

 

https://workshoppist.com/car-alternator-charge-agm-battery/

Read it. Hmmm. All this time I was feeling like my alternator voltage output was dropping after it started to get hot.... but maybe it's more likely, its dropping after it feels like my battery is fully charged ? Now, to be quite honest, lets say that keeping my charging up to 14.5 volts "at all times" were to shorten my battery life by 50% (or less) ..... I'd probably be willing to accept this tradeoff. Heck, my battery only costed $179 at Sam's Club. If I only got 2 years out of it, instead of 4, but was able to have 14.5 volts the entire time, that would be worth it to me.

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Yes, if you manage to program your alternator to maintain 14.5V at all times, it will shorten the life of your battery. If it's an AGM battery, 14.5V is too low for the absorption phase and too high for the float phase. If your battery is a simple lead-acid, then 14.5V should be fine for bulk and absorption, but too high for float. An AGM battery is more sensitive to these problems than a lead-acid and will die sooner as a result. That's what I recall from those articles anyway. I wouldn't expect any other ill effects as a result. If you're ok with that tradeoff then go for it.

 

I think you'll have some challenges in overcoming your vehicle's charging controls, since they're likely build into the ECU, but ECU's have been fooled before. Where there's a will there's a way.

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