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Discussion Starter #1 (Edited)
Not so much on this forum, which seems to lean towards SQ vs. SPL, but on other forums, 99% of the members are constantly talking about wanting / needing HUGE battery banks, of 6 or 8 batteries.... or BIG lithiums of 95 ah, or 150ah's or whatever ridiculous amount of storage they can come up with.

I'm going completely against that train of thought. My feelings are, make enough juice to begin with, and you won't need to store chit ! My 320 amp alt makes 200+ amps, under the worst conditions (at idle, on a hot day). My two amplifiers don't use 200 amps when I'm beating the chit out of them. The only small issue I have, is covering the microsecond voltage drops from quick kick drums and such, and I feel if I could ever get these stinking super capacitors, I would have that covered too.
IF I were to ever double or triple my amplifiers (my wattage output) I would totally double or triple my power generation first, by adding one or two more big, strong alternators. But still, I see zero reason to need more storage.
Their are a lot of guys who just believe that one has to have more storage, because somebody else told them so. But still, I'm looking for one of those guys to explain to me why this is so ?

Can one of the electrical gurus here, explain to me why more storage is necessary if you can make enough juice, right from the get go ? How about 1 nice strong AGM battery, and a sufficient super cap bank ?

Even in an extreme case.... What if you could generate 1500 amps continuous, your system drew 1300 amps peak, and you were running a single 90 amp AGM battery, and a sufficient super capacitor bank. What would be the problem with this ?
 

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If you read other forums you get their misinformation, if you read this one you get our misinformation. Reading is great and all but gotta be able to filter fact from fib.
Just know that both SQ and SPL are based on diminishing returns.

240A alternator or less and one battery should satisfy most people's needs. Some may say one group or the other is doing it wrong.
 

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And you know from the other thread that I'm just not a fan of running an upgraded alternator - hell I hate the extra HP and MPG penalty that turning on the AC puts on the engine! :LOL:

Definitely interested in your supercap experiment. Normally I'd say "a capacitor's job isn't to hold voltage up, it's to discharge as it drops to allow the battery enough time to rise to produce current", but when you do the capacitor time calculation with capacitors that are hundreds of farads, it's pretty crazy to think it's possible your voltage might not drop much at all, if it's just the quick kicks and things at full-slam volume levels that you are seeing any voltage drop.
(and not to beat a dead horse from that other thread, but voltage drop isn't a bad thing - provided you have a capacitor to protect your battery from getting physically slammed, potentially cracking battery plates, from such high demand in timeframes too fast for chemical-based batteries to rise).

Why run 6 or 8 batteries?
Why jack up a truck 2 feet and put it on giant tires? Make it belch black smoke? Some guys weren't blessed with good genetics and have no one but their father to blame for their tic tac sized need-to-compensate.

In reality, I suspect they do it because they did NOT upgrade their alternators, or have such unbelievably inefficient systems that they think they need to run subwoofer amps that are 3000w RMS or more, so that every time the bass hits, it does draw 200a of current... maybe 300a of current... maybe more. So, under the assumption that the battery's barely going to keep up, might as well have as many batteries charged as possible, so that we can go out and drive a long time with the system on THE WHOLE TIME and will make it home without voltage falling much.
Or, there's some SPL competitors who buy and run 15v batteries - the alternator isn't really in the equation there either, they are just burping and going home. When your van is lined with poured cement and has 2" thick bulletproof lexan windows that don't roll down, who cares if you have an electrical system that can do more than burp?

Obviously I'm biased because I'm a fan of building an efficient system, SPL included. It's not hard to make a larger-than-suggested enclosure and model things up to align your peak excursion with a smaller amp rather than a larger amp, if you have space, or get creative with space (spare wells, trunk sides, etc). Power just isn't the way to get there, IMO... it takes a fourfold increase in power to double your actual volume, and that's not a ratio that works for me, when you could double your subwoofers (and power) to double your volume. Scenario B rocks all night, no strain. Scenario A is setting subs and batteries on fire. Plus, when you get to the cruise night spot, and I'm as loud on 400w as the guy to the right with his 4000w and trunk weighed down with batteries - are you really impressed by that guy? 😉
I'm just not a fan.
 

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All these efforts are taken because the alternator cannot respond fast enough.

I would be looking some large resistive load, and a circuit to shed power into the load when the system is not requiring power, and then shutting that off when the power is needed... thereby keeping the alternator always loaded.

But I am running regulated amps, and at a fraction of the power that you run.
 

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Discussion Starter #5
And you know from the other thread that I'm just not a fan of running an upgraded alternator - hell I hate the extra HP and MPG penalty that turning on the AC puts on the engine! :LOL:

Definitely interested in your supercap experiment. Normally I'd say "a capacitor's job isn't to hold voltage up, it's to discharge as it drops to allow the battery enough time to rise to produce current", but when you do the capacitor time calculation with capacitors that are hundreds of farads, it's pretty crazy to think it's possible your voltage might not drop much at all, if it's just the quick kicks and things at full-slam volume levels that you are seeing any voltage drop.
(and not to beat a dead horse from that other thread, but voltage drop isn't a bad thing - provided you have a capacitor to protect your battery from getting physically slammed, potentially cracking battery plates, from such high demand in timeframes too fast for chemical-based batteries to rise).

Why run 6 or 8 batteries?
Why jack up a truck 2 feet and put it on giant tires? Make it belch black smoke? Some guys weren't blessed with good genetics and have no one but their father to blame for their tic tac sized need-to-compensate.

In reality, I suspect they do it because they did NOT upgrade their alternators, or have such unbelievably inefficient systems that they think they need to run subwoofer amps that are 3000w RMS or more, so that every time the bass hits, it does draw 200a of current... maybe 300a of current... maybe more. So, under the assumption that the battery's barely going to keep up, might as well have as many batteries charged as possible, so that we can go out and drive a long time with the system on THE WHOLE TIME and will make it home without voltage falling much.
Or, there's some SPL competitors who buy and run 15v batteries - the alternator isn't really in the equation there either, they are just burping and going home. When your van is lined with poured cement and has 2" thick bulletproof lexan windows that don't roll down, who cares if you have an electrical system that can do more than burp?

Obviously I'm biased because I'm a fan of building an efficient system, SPL included. It's not hard to make a larger-than-suggested enclosure and model things up to align your peak excursion with a smaller amp rather than a larger amp, if you have space, or get creative with space (spare wells, trunk sides, etc). Power just isn't the way to get there, IMO... it takes a fourfold increase in power to double your actual volume, and that's not a ratio that works for me, when you could double your subwoofers (and power) to double your volume. Scenario B rocks all night, no strain. Scenario A is setting subs and batteries on fire. Plus, when you get to the cruise night spot, and I'm as loud on 400w as the guy to the right with his 4000w and trunk weighed down with batteries - are you really impressed by that guy? 😉
I'm just not a fan.
I really haven't noticed any drop in power, or mileage. Obviously their has to be some, but it must be so small I don't notice it.
Nothing wrong with an efficient system either. But how about "an efficient" 3 or 5Kwt system 😀 lol
 

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Discussion Starter #6
All these efforts are taken because the alternator cannot respond fast enough.

I would be looking some large resistive load, and a circuit to shed power into the load when the system is not requiring power, and then shutting that off when the power is needed... thereby keeping the alternator always loaded.

But I am running regulated amps, and at a fraction of the power that you run.
But correct me if I'm wrong, 10 batteries will hardly respond and "faster" than one. They just give you more reserve. Lithium are quite a bit faster than lead acid..... But they are still like a snail, compared to super caps.
 

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Lithiums are only faster if the batter is designed to be faster, and not a deep cycle style.

Just like a lead acid starting battery versus a LA deep cycle.

But back to speed...
How fast can the amp demand current?
A subwoofer is usually low pass limited, so an impulse really has some number of milliseconds before the current demands gets high.

Then the alternator also has some bandwidth, and takes some number of milliseconds to respond.

While the super cap is interesting, one could change the alternator to have a faster response time... (maybe... and if the inductance is high, then maybe not). One could probably (with some EE and raspberrypi skills) have the audio signal bass channel put some preemphasis onto the alternator in order to ramp it up ahead of time.
It may require a TA delay on all the channels, but it should then have the alternator spitting out more current, just as the amplifier start series demanding it... and wholla it should be like magic.
It would be like a cruise control seeing a hill (if it had GPS), and the cruise control starts mashing the throttle as it hits the hill, rather than looking at the speed going down after it starts going up the hill.

Or a more concise way of putting it, is that the capacitors and batterys are bandaids, to make up for the alternators slow response.
Just fixing the alternator seems more direct.
 

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Not so much on this forum, which seems to lean towards SQ vs. SPL, but on other forums, 99% of the members are constantly talking about wanting / needing HUGE battery banks, of 6 or 8 batteries.... or BIG lithiums of 95 ah, or 150ah's or whatever ridiculous amount of storage they can come up with.

I'm going completely against that train of thought. My feelings are, make enough juice to begin with, and you won't need to store chit ! My 320 amp alt makes 200+ amps, under the worst conditions (at idle, on a hot day). My two amplifiers don't use 200 amps when I'm beating the chit out of them. The only small issue I have, is covering the microsecond voltage drops from quick kick drums and such, and I feel if I could ever get these stinking super capacitors, I would have that covered too.
IF I were to ever double or triple my amplifiers (my wattage output) I would totally double or triple my power generation first, by adding one or two more big, strong alternators. But still, I see zero reason to need more storage.
Their are a lot of guys who just believe that one has to have more storage, because somebody else told them so. But still, I'm looking for one of those guys to explain to me why this is so ?

Can one of the electrical gurus here, explain to me why more storage is necessary if you can make enough juice, right from the get go ? How about 1 nice strong AGM battery, and a sufficient super cap bank ?

Even in an extreme case.... What if you could generate 1500 amps continuous, your system drew 1300 amps peak, and you were running a single 90 amp AGM battery, and a sufficient super capacitor bank. What would be the problem with this ?
SPL types tend to turn their systems on for hours at a time at car shows/spl competitions, so they actually need lots of batteries, not to mention the fact that you can only add so many alternators to an engine bay before you run out of space.
 

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Not so much on this forum, which seems to lean towards SQ vs. SPL, but on other forums, 99% of the members are constantly talking about wanting / needing HUGE battery banks, of 6 or 8 batteries.... or BIG lithiums of 95 ah, or 150ah's or whatever ridiculous amount of storage they can come up with.

I'm going completely against that train of thought. My feelings are, make enough juice to begin with, and you won't need to store chit ! My 320 amp alt makes 200+ amps, under the worst conditions (at idle, on a hot day). My two amplifiers don't use 200 amps when I'm beating the chit out of them. The only small issue I have, is covering the microsecond voltage drops from quick kick drums and such, and I feel if I could ever get these stinking super capacitors, I would have that covered too.
IF I were to ever double or triple my amplifiers (my wattage output) I would totally double or triple my power generation first, by adding one or two more big, strong alternators. But still, I see zero reason to need more storage.
Their are a lot of guys who just believe that one has to have more storage, because somebody else told them so. But still, I'm looking for one of those guys to explain to me why this is so ?

Can one of the electrical gurus here, explain to me why more storage is necessary if you can make enough juice, right from the get go ? How about 1 nice strong AGM battery, and a sufficient super cap bank ?

Even in an extreme case.... What if you could generate 1500 amps continuous, your system drew 1300 amps peak, and you were running a single 90 amp AGM battery, and a sufficient super capacitor bank. What would be the problem with this ?
I think you're over thinking your system, just go with your planned single or dual battery plus super capacitor bank and you'll be good.
 

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Discussion Starter #10
Lithiums are only faster if the batter is designed to be faster, and not a deep cycle style.

Just like a lead acid starting battery versus a LA deep cycle.

But back to speed...
How fast can the amp demand current?
A subwoofer is usually low pass limited, so an impulse really has some number of milliseconds before the current demands gets high.

Then the alternator also has some bandwidth, and takes some number of milliseconds to respond.

While the super cap is interesting, one could change the alternator to have a faster response time... (maybe... and if the inductance is high, then maybe not). One could probably (with some EE and raspberrypi skills) have the audio signal bass channel put some preemphasis onto the alternator in order to ramp it up ahead of time.
It may require a TA delay on all the channels, but it should then have the alternator spitting out more current, just as the amplifier start series demanding it... and wholla it should be like magic.
It would be like a cruise control seeing a hill (if it had GPS), and the cruise control starts mashing the throttle as it hits the hill, rather than looking at the speed going down after it starts going up the hill.

Or a more concise way of putting it, is that the capacitors and batterys are bandaids, to make up for the alternators slow response.
Just fixing the alternator seems more direct.
I'm totally aware that they make both lead acid, and Lithiums, in both regular high output, and deep cycles. But I don't think the difference between regular, or deep cycle, with either lead acid, or Lithium is as huge (regarding speed of discharge) as it is with super caps. Super caps are just a whole different thing.

However, I like your thinking out of the box with a system which can "see peaks of power use coming" and ramp up for it micro seconds ahead of time.
I've considered the same kind of thing with the system seeing that it was going to clip, and dialing it back to prevent it, before it happens.
 

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Discussion Starter #11
I think you're over thinking your system, just go with your planned single or dual battery plus super capacitor bank and you'll be good.
"Single" battery for sure 😉

Not overthinking though. I'm just saying, I believe a lot of people are not "thinking at all" but rather, just jumping on the more battery train because that's what they have been tol
 

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Discussion Starter #12
SPL types tend to turn their systems on for hours at a time at car shows/spl competitions, so they actually need lots of batteries, not to mention the fact that you can only add so many alternators to an engine bay before you run out of space.
I think your missing my whole point though. If you make more power continuously than your system can use, you do not need any additional storage.
And with the money a lot of guys spend on batteries... Multiples of very expensive models, they could go on and just get a few alternators to make enough power that they don't need additional storage either.
My 320 amp alternator cost about the same as guys spend on some high end batteries... $359. I'd buy and run another one or two of them, before I'd buy another battery.
But I'm actually good right now just as it is 🙂
 

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I think your missing my whole point though. If you make more power continuously than your system can use, you do not need any additional storage.
And with the money a lot of guys spend on batteries... Multiples of very expensive models, they could go on and just get a few alternators to make enough power that they don't need additional storage either.
My 320 amp alternator cost about the same as guys spend on some high end batteries... $359. I'd buy and run another one or two of them, before I'd buy another battery.
But I'm actually good right now just as it is
When I say they run their systems for hours, I mean without the engine running. In your case, and mine, one or two batteries and a good alternator is all we need, we don't even need supercaps, but you can try them.
 

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Discussion Starter #14
When I say they run their systems for hours, I mean without the engine running. In your case, and mine, one or two batteries and a good alternator is all we need, we don't even need supercaps, but you can try them.
Yea, I definitely never play my system with the truck not running.

I'm definitely having micro second voltage dips.... As evidenced by my dash lights flickering. SO anxious to get the supercaps, but having the damnedest time getting ahold of any ☹
 

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...
However, I like your thinking out of the box with a system which can "see peaks of power use coming" and ramp up for it micro seconds ahead of time.
I've considered the same kind of thing with the system seeing that it was going to clip, and dialing it back to prevent it, before it happens.
It is going to be milliseconds to 10s of milliseconds.

Your super caps do nano seconds or pico seconds... but who cares because the demand is super slow. So it is not like it will matter over a slow capacitor.

Pulsing a subwoofer is not like pulsing laser.
 

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I believe alternator speed must be a function of inductance, but I thought what occurred (instantly) was voltage drop.

And you'd hope that the voltage drop wouldn't fall any further than the 12.5v level of the battery, but THAT chemical reaction IS slow, and not only that but that chemical demand immediately slams the plates in the battery, which can/will crack and kill your battery.

In a way, multiple batteries could help buffer the impact, distributing that strain - but they ALL still have the same speed limitation, you won't stop voltage from falling PAST the 12.5v level of the batteries... 12v... 11.5v... 11v... Where she stops nobody knows...
Until the batteries start contributing, then voltage stabilizes at the 12.5v level...
And "deep cycle" batteries are an alternative strategy to multiple batteries, to avoid killing batteries, since they have thicker plates inside... Unfortunately that makes them even slower.

When the demand stops, then voltage stabilizes back at the alternator 14.4v level and the batteries recharge what little they lost nearly as fast as they supplied current for (the more batteries, the longer that recharge time, and the bigger inherent burden of additional loads on the alternator - but the more reserves).

It's why it's frustrating and silly to hear people claiming "capacitors don't do anything". First off that's fundamentally a silly thing to say - to the level of a "flat-earther" level of electrical-engineering-denial.
Especially when there's a simple time formula for capacitance and current. It's real.

And it's inexpensive and easy. All that happens is - the capacitor voltage floats at whatever the system voltage is. When it drops, the cap dumps current into the system- and since it's a current demand causing causing the drop, that slows the drop.

So - not only should that protect the battery (and reduce the drama), that should help the alternator as well, since the very instant the voltage drops below 14.4, the cap begins discharging.

Like Holmz says - there's no theoretical-perfect 0-ohm, therefore truly-instant capacitor... But they are plenty fast for this stuff.

And I am interested in the speed of these super-caps too. I am guessing they are at least as fast as old school electrolytics?
I don't understand how the leads can be so small, though... Even 1F caps have bolts, to hold ring terminals with fat power wire attached, for the potential for huuuge current to flow in and out...
...so a 200F cap, I mean holy cow... The current potential would be equally magnified, right?
Huuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuge?
So how are the leads so small?
I don't want that to be my reason for skepticism - but I'm very interested in FishChris's results.
I'm hoping it's big bang for the buck - with no bang.
Or fires.

Sent from my LM-G710 using Tapatalk
 

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Discussion Starter #17
I believe alternator speed must be a function of inductance, but I thought what occurred (instantly) was voltage drop.

And you'd hope that the voltage drop wouldn't fall any further than the 12.5v level of the battery, but THAT chemical reaction IS slow, and not only that but that chemical demand immediately slams the plates in the battery, which can/will crack and kill your battery.

In a way, multiple batteries could help buffer the impact, distributing that strain - but they ALL still have the same speed limitation, you won't stop voltage from falling PAST the 12.5v level of the batteries... 12v... 11.5v... 11v... Where she stops nobody knows...
Until the batteries start contributing, then voltage stabilizes at the 12.5v level...
And "deep cycle" batteries are an alternative strategy to multiple batteries, to avoid killing batteries, since they have thicker plates inside... Unfortunately that makes them even slower.

When the demand stops, then voltage stabilizes back at the alternator 14.4v level and the batteries recharge what little they lost nearly as fast as they supplied current for (the more batteries, the longer that recharge time, and the bigger inherent burden of additional loads on the alternator - but the more reserves).

It's why it's frustrating and silly to hear people claiming "capacitors don't do anything". First off that's fundamentally a silly thing to say - to the level of a "flat-earther" level of electrical-engineering-denial.
Especially when there's a simple time formula for capacitance and current. It's real.

And it's inexpensive and easy. All that happens is - the capacitor voltage floats at whatever the system voltage is. When it drops, the cap dumps current into the system- and since it's a current demand causing causing the drop, that slows the drop.

So - not only should that protect the battery (and reduce the drama), that should help the alternator as well, since the very instant the voltage drops below 14.4, the cap begins discharging.

Like Holmz says - there's no theoretical-perfect 0-ohm, therefore truly-instant capacitor... But they are plenty fast for this stuff.

And I am interested in the speed of these super-caps too. I am guessing they are at least as fast as old school electrolytics?
I don't understand how the leads can be so small, though... Even 1F caps have bolts, to hold ring terminals with fat power wire attached, for the potential for huuuge current to flow in and out...
...so a 200F cap, I mean holy cow... The current potential would be equally magnified, right?
Huuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuge?
So how are the leads so small?
I don't want that to be my reason for skepticism - but I'm very interested in FishChris's results.
I'm hoping it's big bang for the buck - with no bang.
Or fires.

Sent from my LM-G710 using Tapatalk
Hey Geo, I only wish I could find a graph, which showed the speed of power delivery of regular lead acid batteries vs. AGM's vs. Lithium's vs. Super capacitors

And even more importantly, I wish I could just get ahold of these darn Super Capacitors :(
 

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Hey Geo, I only wish I could find a graph, which showed the speed of power delivery of regular lead acid batteries vs. AGM's vs. Lithium's vs. Super capacitors

And even more importantly, I wish I could just get ahold of these darn Super Capacitors :(
Well - you could equally effectively look for [either general or specific] internal resistance, in ohms, for all those. The speed is proportional - half the resistance, double the speed.

It's only the alternator that wouldn't have speed limited by resistance - Holmz has to be right that it's inductance, there. Maybe there's other factors, but that sounds right. I never really thought of the "speed to problem" side... Just always worked through the "speed to recovery).
His is an interesting point that actually would (like RPM) seem to present a new spec to consider looking for when shopping for an aftermarket alternator - probably another spec that's creatively hidden. 😉

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Discussion Starter #19
Well - you could equally effectively look for [either general or specific] internal resistance, in ohms, for all those. The speed is proportional - half the resistance, double the speed.

It's only the alternator that wouldn't have speed limited by resistance - Holmz has to be right that it's inductance, there. Maybe there's other factors, but that sounds right. I never really thought of the "speed to problem" side... Just always worked through the "speed to recovery).
His is an interesting point that actually would (like RPM) seem to present a new spec to consider looking for when shopping for an aftermarket alternator - probably another spec that's creatively hidden. 😉

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Yes. And then their is an even bigger question (IMPO) how much capacitance do my amplifiers already have ???
I'm sure that some cheap garbage amps would have very little, and might have more to gain from extra capacitance. While some high $ top end models might not benefit as much. I'd love to be able to talk with someone who actually builds my amps, especially my subwoofer amp ... Wolfram.... But those have a Chinese board... So I'd need a translator 🤔

I'm betting that a capacitor bank will make a pretty big difference.... But like so many other things, I'd bet it falls under the "deminishing returns" category.
I'm guessing that a 500 farad cap bank might be 20 X's more than the amp contains, for a 10% difference....
 

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SPL types tend to turn their systems on for hours at a time at car shows/spl competitions, so they actually need lots of batteries, not to mention the fact that you can only add so many alternators to an engine bay before you run out of space.
Most use high amperage battery chargers at shows. I'd like to get one when turning my system in the garage so I don't have to run my engine.
 
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