Featured How Much AH for ~ 250 Amps

Blackout67 said:

Hes not getting that 220 amps at idle tho. When I got the spreadsheet for my 320 amp HO alternator when it was tested, idle output was near 100 amps and the full 320 amps didnt kick in till like 2.2k rpms. You dont need a steady supply to match your amp exactly unless your running full tilt burp sine waves.

As was mentioned, music is dynamic and the average power draw will not always be equal to what its actually capable of at max output. You dont need a HO alt if your battery capitance is sufficient to take a hit and recharge before the next one

Also thag 3 Farad capacitor is doing nothing for a system of that output, especially with a red top.

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Doxquzme said:

It's not unequivocal; it's conditional - not everyone, actually, 95% of the people setting up 2k systems are EVER going to need an upgraded alternator, that's a fact, not an opinion.

LifePo4 and Lithium options not only store enough reserve ( and replensish it quickly when not needed), but they will also deliver a burst at much faster rates than a flooded or AGM can, not as fast as a cap, but your 5 farad capacitor, with little to no reserve (and one reason to actually have an HO alt) well, it's tapped out long before a similarly priced LifePo4 battery, not even close.

One has to take into account the balance between the various options, and what works best, which is to say, one is not more "correct" or "incorrect" than the other.

There are considerations with upgrading an alternator, such as different pulley sizes, belt sizes, reduced mileage, and reduced power.

In a Mustang GT, you're not going to notice, so there is that.

It's a far more difficult option, almost impossible in some newer cars, not so much in older ones, due to various electrical functions that are tied to the way it operates.

Additionally, not everyone can get under the hood and change out an alternator, and while I'm fully capable of such, it's locatioin makes it a real PITA for some.

All these options are viable; one is not better than the other, unless the system demands it, and then it's likely going to be a combination of both HO alt and lithium support.

In the 2-3k wattage systems, new battery tech provides an absolutely viable option, an option, and in my experience, that is an easier and often less costly and less labor-intensive option as well.

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DOX and Blackout,
I will have to push back on you with this one. I have built and experimented with so many big systems that I was able to see what happens under all conditions. If you want to speak of facts, then I will lay the facts down.

• Manufactures do not install alternators to supply extra power for add-ons. They install what the vehicles needs.
• Do you NEED an upgraded alternator? No! You can dump $1000 into bigger power banks and/or batteries, but I don't give a rip about what you say, that route is just a band aid for a daily driver. The amount of stress that is put on your factory alternator will cause it to fail much sooner.
• Bass is not the only thing that will drain a system. Any loud sound, an amp generates, will draw power a lot of power. Hard hitting bass will drain the most because we tend to tune it to be loud. Pushing 500 watts from your mids and highs is the same as pushing 500 watts from a subwoofer.
• A weak alternator will not recharge a battery faster than some bass hits. What happens when your playing longer bass tunes, and overall loud music, for a longer period of time. The alternator can't keep up. Your battery might appear to be charging, but chances are, it's only a surface charge.
• A high amp alternator will take more power to spin, but only when the system is calling for more power.
• A putting 100 pounds of batteries, in your car, will burn more fuel, overall, than an upgraded alternator.
• You don't need to upgrade your pullies with an upgraded alternator. You only need to do that if you want full amperage at engine idle. Only competition vehicles do that.
• All the professional SPL competitors have multiple alternators in their vehicles? If upgraded alternators are crap, then why do they use them?

Again, guys. I have run 1000 watts off a stock electrical system, a stock alternator with multiple Stinger batteries, stock electrical system with a capacitor, upgraded alternator with standard battery, etc... I literally showed you guys my pictures that shows I am not a backyard wannabe installer. I have installed 100's, if not 1000's, of big systems well over 1000 watts. I have done all this crap in real life at real shops. Some of you personally know the shops I have worked at.

SO, you asked what the best route is? Upgrade your alternator, add a high quality battery near the amps, which a 50ah would be just fine, and add a quality capacitor. AND YES, that 5 farad capacitor, in my son's truck, is helping the system. That's why I don't have any lights flickering, and of course I know the alternator isn't pushing out full amperage at idle. That's MECP 101. You want a tip? When idling, turn your AC on and your RPM's will go up. That will produce a bit more amperage from the alternator.

I think you may have missed the point.

It's a matter of applied science, and your one-size-fits-all approach as the best initial solution is incorrect.

Ever hear the expression, "thoughest protest too much"?

Nobody said upgrading to an HO alt is crap, far from it.

But I guarantee you my 12lb lithium solution is easier, more practical, MORE FUEL EFFICIENT, will outperform up to a point, and is less labor intensive and applicable in as many ways as your HO alt solution - for 2k-3k systems.

Not sure why you feel that most people will actually see the kinds of draws that are theoretically possible; they are rarely going to the kind of draw that one sees in SPL builds (and I know how to do those too).

And hey, if they do or actually think they might, then by all means consider both an auxiliary battery, a large capacitor of 50 farads or more, or lithium to go along with all that additional output!

Nobody said an HO is a bad thing or that you shouldn't do it, but as the first thing, nah, you are out of the loop, stuck in a time that gave people few alternatives that are available these days.

I prefer my approach, you prefer yours, but saying everyone else is wrong, that confuses those who are looking for information to engage people on a subject that too often than not, gets a my-way-or-highway approach.

HO alternators will never replace lithium or large supercaps for large instantaneous electrical support for BASS reinforcement: it's not instantaneous, and it's limited by it's max output, so it's really not even close.

Batteries on their own will not replace the need for HO alternators, in systems where you start to exceed the ability of good Lithium support to fill the gap.

A 5 farad fcap does do a bit, but it's not substantial; that is a measurable thing, like it or not. I'm all for using capacitors in the right setting, but why would anyone spend $175 to $250.00 on a 5-10 farad capacitor when, for $350.00, you can get 500-650 farad supercapacitors?

On that same note, an AH rating is irrelevant (almost anyway) unless you need a lot of storage; it's not a functional spec comparatively, it's quite literally the size of the battery's fuel tank.

AH specifications are simply a measurement of "Ampere-Hours" in that it's a measurement of the battery's total energy capacity. Specifically, it indicates how many amps of continuous current a battery can supply over one hour before running out of charge.

It won't tell you how well it will regulate voltage, how fast it can provide an instantaneous burst or constant draw, it's quite literally the battery's fuel tank, not the motor.

A 200AH AGM battery will lag far behind the performance of a 12AH GloweVoltage Series 3; the performance of a GV will destroy it.

We all have something to share from years of experience, heck, I've got 3 generations of electrical engineering backing the talk, so there is that.

45+ years in loudspeaker design and home and car audio, we've all got stuff to contribute.

That's some substantial hands-on applied electrical theory and sound recording experience, and it's all basically math, and the math doesn't lie.

I've seen your work, appreciate the build quality and dedication to the craft, but the only "best way" to do anything is to analyze the needs based on sound (electrical) theory, because the one-size-fits-all approach is just not an accurate way to approach something that has so many variables.

Presenting one's ideas as possible solutions as you see them and for reasons that are backed by sound electrical theory, is a great thing.

Steering people in the one direction you're comfortable with, when it's limited in scope and application, and proclaiming it's "the" way, that's just being stubborn.

I will throw this in here. My daily driver is an early 2000’s GM car with just over 100k on it. It’s still running the factory 130a alternator. The battery on this car is located under the back seat. I replaced the regular battery with a JY power hp40. I am running a Taramps smart 3 and a Taramps 800.2. At full tilt on the stereo ( clip light flickering ) I have never seen more than 2 tenths of a volt of drop. It charges at 14.6 -14.7 hot and I have never seen below 14.4. That is with no big 3, no upgrades of anything other than swapping the battery to lithium.

Blackout67 said:

Im not saying you never need an HO. I just dont need one in my case and 95 percent of people will not need one either.
Your sons trucks lights aren't dimming because he has a red top battery that is many many times the capitance than a measly 5 farad. 5 farad when you do the math is going to (under perfect circumstances) be able to discharge 100 watts in around a second. Thats pathetic. Not only that, but it goes directly against your statement regarding putting "stress" on the alternot by adding a other capitance device to the circuit.
A capacitor serves the same function as a battery. It holds a static charge to be used later, it doesnt generate power so it will constantly be needing to be charged because it is such a low capitance, in the face of a 2k watt system without the red top would constantly be drained providing negligible gains.

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A 5-farad cap on a 2000 watt system is not too measly. It's a Stinger cap, so it's a high end one. They charge and discharge faster than any battery on the market. I know they put strain on an electrical system, but that's where the HO alternator comes in. As for holding a static charge, they absolutely do. I have had capacitors, that were unplugged for months, still have a charge on it.

The Red top is a damn good battery, but it still wasn't enough. We started with the factory alternator when he was pushing about 1500 watts. The lights flickered. I was too lazy, at the time, to install the alternator. however, I still did the big-3.

Blackout67 said:

Also no one here is saying youre some backwoods installer, or atleast not that ive read. You say in your experience but we are also here saying in our experience.
In my experience it is not worth the hassle and price of ordering an alternator for $350+ and waiting weeks for it to be built and shipped and potentially have to rip apart the front of my car to get to the alternator (ive installed HO alts on a Focus, it is MISERABLE) than to just add an extra battery into the circuit especially when im running a system that will barely exceed the stock charging system. I dont sit around idling at office buildings making an enemy of myself to the public and I dont sit there and listen to straight bass sine waves. Speaking from my experience of installing systems in the same exact car, I do not need a HO output for this barely 2k watt system im pushing. I dont.
I dont think your son does either with thag red cap and a system of that wattage.

Again all we are saying is that its more complicated than saying you need HO alt and AGM and a capacitor. Does it work? Sure do you need it? Absolutely not. Will buying a $80k truck to commute to your office job work? Sure. Do you need it? Absolutely not

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I was not aware you were looking for the easier way. I believe the original questions was what is the best way. I thought this was going into a Mustang. If so, those alternators can be swapped out in less than an hour. However, front wheel drive cars are a pain, so I get if you don't wish to go that route.

Blackout67 said:

PS. The cars electrical system is designed to support the max amperage load of all circuits. How often are you driving around with all your accessories running at full tilt? I never do. Hell i rarely use my AC. If your voltage is fine youre good.

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Yes, the alternator is designed for the max amperage of the stock electricals. At night, is when you will usually notice the issues with power drops. Day time driving, you don't use a lot. With the sensitivity of electronics, these days, big power fluxes can damage them.

Again, I didn't know you were looking for the easiest way for a power upgrade. Doing the big 3 and adding a HO batter, near the amps, will work. Heck, the big-3, Red Top main battery, and a small 50ah battery will be good.