alternator idle amps

[Blacktank]

what should i be looking for? being gm there are lots of options from the base $35 65 amp to the $100-$150 100-150 amp all the way up to the $400-$500 melt your wires version

saw a few that were rated at around 100 idle amps

[sternwake]

cs-144 is well regarded by the guy who helped me figure out how to rig my chrysler 50/120 alternator for a modified external voltage regulation.


compared to the CS-130, here are some of his recent words

By encouraging the substitution of the CS-144 here is what I was pushing...

Output would increase by 35 amperes
But even at 105 amps output the rectifiers would operate at 65 degrees cooler temperature
Idle RPM would be more than doubled that of the original CS-130
From idle to full output the CS-144 would vastly outperform the CS-130
The CS-144 Will outlive the CS-130 anywhere from five to twenty times as long
That exposed rear bearing on the CS-130 is a red herring.

I beieve he is also adamant the fan which has open blades is much better than the flat slotted one.

I'll see if has any thoughts on externally regulating this alternator so one can seek and 14.7v for as long as desired, which is anytime the battery is less than fully charged.

[Ballenxj]

cs-144 is well regarded by the guy who helped me figure out how to rig my  chrysler 50/120  alternator for  a modified external voltage regulation.


compared to the CS-130, here are some of his recent words

By encouraging the substitution of the CS-144 here is what I was pushing...

Output would increase by 35 amperes
But even at 105 amps output the rectifiers would operate at 65 degrees cooler temperature
Idle RPM would be more than doubled that of the original CS-130
From idle to full output the CS-144 would vastly outperform the CS-130
The CS-144 Will outlive the CS-130 anywhere from five to twenty times as long
That exposed rear bearing on the CS-130 is a red herring.

I beieve he is also adamant the fan which has open blades is much better than the flat slotted one.

I'll see if has any thoughts on externally regulating this alternator so one can seek and  14.7v  for as long as desired, which is anytime the battery is less than fully charged.

What exactly is the CS-144? Is that a complete alternator? And do you by chance have an example of what to look for in open vs slotted?

[sternwake]

Pulled from RockAuto, here is a CS144 with the better fan:



http://www.rockauto.com/en/moreinfo.php?...57&jsn=468

Here is the less desirable( according to my guy) external fan of a CS144



http://www.rockauto.com/en/moreinfo.php?...57&jsn=472


edit: Sorry pic links do not work.

I pulled these images from rockAuto on a 1999 suburban with a 5.7.

I Do not know if they changed the mounting offset or what modification, if any, is required to mount them.

I am also unsure of how they are wired up, regarding voltage sense and ignition feed.

Looks like they have a special connector for those functions:

http://www.rockauto.com/en/catalog/chevr...ector,2528

I am not personally familiar with these alternators.

[Baloo]

The reason there are so many options on amperage is because they are based on what options your vehicle came with. A van that has power windows and power locks, A/C and what not will use more power than one that doesn’t. The higher the amperage, the better in a sense. Remember they have voltage regulators to adjust the output depending on the demand and the state of the battery. I would suggest getting a good quality over 100 amp one incase you want to use it to charge your house batteries too when the engine is running.


Sent from my iPhone using Tapatalk

[Ballenxj]

Pulled from RockAuto, here is a CS144 with the better fan:

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http://www.rockauto.com/en/catalog/chevr...ector,2528

I am not personally familiar with these alternators.

Ah, thanks. I see what you were talking about now, and no worries on the picture llinks as I just clicked on the Rock Auto links anyway.

[sternwake]

Alternator Voltage regulators have no idea the state of the charge of the battery.

The alternator makes as many amps as it can, or needs to to achieve the system voltage sought by the voltage regulator

Many of these will simply goto 14.2v and once they get hot drop to 13.8, and when really hot 13.6.

MOst are quite dumb and their intent is not to quickly recharge batteries, but top up a slightly depleted starting battery, and prevent its discharge when all the stock vehicle loads are running at once.

Even those VRs internal to engine computers are not very sophisticated and were never programmed with an additional circuit of depleted house batteries tacked on.

The most recent VRs in modern vehicles intentionally keep the battery at around 80%, all in an effort to eek out 0.05% more MPG. When braking or letting off the gas these will up the voltage, increasing load on alternator and engine on;ly then. If the battery was fully charged then upping the voltage would not add any more load to alternator, and make the strategy even marginally effective, so they aim to keep the battery around 80%, so the battery can accept higher amperage when the VR asks for 14.5ish volts when braking.

Everything about proper battery charging is about getting the batteries to the right voltage for long enough.

when a battery is depleted, about 1/3 the amps will flow at 13.6v compared to 14.7v.

Many Alternator outfits claiming huge idle amperages are primarily designed for powering huge loads like macking stereos, and these are fine with 13.6v, but a depleted house battery bank needing to be recharged quickly driving from from A to B or simply needs 15 minutes of idling to get out of the dangerously depleted area, needs 14.7ish volts to make the alternator work to near its potential.

Alternators can be incredible high amperage charging sources, when their voltage regulators are asking it to make enough amperage to seek and maintain mid to 14 volts. When there are loads requiring it, and a well depleted battery is a considerable load. Always holding a starting battery at 14.5v, will cause overcharging and waterloss and shorten battery life through positive plate shedding.

So they compromise and say 13.6 or 13.8v is fine and dandy. Depleted batteries would be better served by 14.5v, when charging times are limited.

So the effective house battery charging has a voltagr regulator which allows mid to high 14's, and a ci

Thick copper circuit which will not heat up become more resisitive, and drop voltage passing high amperage.

If a battery requires 60 amps to be held at 14.5v, then a 200 amp alternator is not going to recharge it any faster than a 100 amp. The difference is the 200 amp model should better be able to handle the heat it generates, which can be considerable.

The CS144 GM alternator is a reliable workhorse. If modified with external regulation it can be made into a VERY effective bulk charger for house batteries. Even if unmodified it will outperform and outlast the CS-130.

reman'd cs-144s are about 100$. The speciality Alternator claiming huge amperages likely use the same casing and rewind the armatures and stators to atempt to get more performance from them.

I'd be happier if my alternator could produce 75 amps at idle when hot, as opposed to the ~50 it can do, but so be it. A couple hundred more rpm and I can get the battery to 14.7 no worries, and that is basically as fast as a battery can safely be recharged.

[TWIH]

SW, thanks for the info, as usual. It does seem that the larger case alternator would handle heat somewhat better, that alone could be worth the extra expense. 

One question I have is that "expert sources" always say that the alternator doesn't do a good job of bring a FLA battery up to or near 100%, soooo, how come starting batteries can last for 5-7 years or longer, if not run down?  

All the recharging starting batteries usually ever see is done by driving, and some, like my neighbor in the condo, only get 2-3 miles a day of putting around the area.  He never goes anywhere more than 35 mph or at most 5 miles away and he doesn't use a supplemental battery charger, yet his 2011 Ford Escape just got it's original battery replaced last year (so 6 years), an dthats because he left an interior dome light on... 

If a regular alternator can keep that basic original equipment starting battery that healthy, why can't a large alternator keep a house battery healthy past 1-2 years (like a marine grade battery used in an rv)?  I've never been able to figure that one out.

A blog comment about the average life of a car battery being 3-5 years brought this response: http://carbibles.blogspot.com/2013/02/yo...-your.html

"I keep reading this statement that batteries are only good for 2 or 3 years and honestly I don't believe it.


I owned a '96 Subaru Legacy in Ottawa Canada (annual swings -25C through +35C, plus humidity) for twelve years, and it left with the battery it shipped with. We owned a '98 Mazda 626 that we got in 2001 for eight years, and it left with the battery that it came to us with. My wife's Yaris is over 5 years old, no battery issues. And my Mazda 3 is only three years old, but I don't even think about the battery. Including my first beaters, I've owned six cars, and I think total I've purchased one battery -- that one of my beaters needed because it had been a driveway bunny for two years before I drove it.

Now maybe I'm doing something that means my batteries get extraordinary long life? -- but frankly I don't believe it."

End of quote

Now I know that simply leaving an interior light on can "kill" a starting battery or significantly reduce its' lifespan, but if those things have not occurred, it seems that alternators do a pretty good job (what they were designed to do,  power loads and top off the battery).  So why can't a bigger capacity alternator with proper wiring not take good care of a house battery?

[sternwake]

The Only reason an alternator cannot take proper care of the depleted house battery, Is the voltage regulation. The alternator is told to make X amount of amps required to raise voltage to and hold XX.XX volts, by the voltage regulator.



The amount of time required to get from 80% charged to 100% charged is about 3.5+ hours on a healthy battery at mid 14 volts, longer and perhaps higher voltage required on an older battery.

It requires very little capacity of a starting battery, to start the vehicle. Their ability to still crank an engine when seriously degraded, is mostly responsible for the 5 + year lifespans some report. A house battery as degraded, would be obvious to the person who watches a voltmeter while the battery is loaded with normal loads, or perhaps the low voltagge alarm on the inverter would start screaming at them.


That and the average temperature of the battery underhood. Some vehicles have the battery insulated from direct engine heat, others no so much, or at all. Batteries in some German vehicles are inside the trunk, and easily go 8 years before they will start cranking slower, noticeably.

The cycling of a battery is much much harder duty than the task of a starter battery. When one cycles to 50% 7 days iin a row it is inportant to restretch that battery casing to 100% recharged Soon, and this will take longer then if one brought it back to full on day one and close as possible to it each day.

Starting batteries can and do hover in the 80 to 85% charged area much of thier life, and still start the engine, until it gets really cold.

If one wants to maximuize alternator contribution to house battery, one needs to be able to get the battery to and hold it at, 14.4+ volts the whole time the engine is running while the battery is still less than 100% charged.

Hot batteries should have voltage reduced accordingly. Cold batteries raised. Ideally.

Most vehicles will not hold 14+ volts for very long, and much much less recharging happens at lesser electrical pressures. Voltage drop on too long too thin wiring compounds the inefficacy.

Morning alternator blasts, and all day solar can keep batteries happy enough for long enough, in many cases, as long as they are not drawn to 20% state of charge each discharge cycle.

My last wally world battery lasted 7 years, but it could not recharge my phone, and then still start the engine. But If I parked for 3 days with no load on the battery, it had no issues starting my engine.

Truth is at 23 months of age it was seriously degraded, capacity wise, but it still worked at the task of engine starting, for 4 more years, and I rarley fed it with my solar. Was mostly fed a diet of alternator 14.9 brevity followed by 13.7 for those 4 years, and Still could start my engine when I traded it for a core charge. on a new marine battery.

[Ballenxj]

The Only reason an alternator cannot take proper care of the depleted  house battery, Is the voltage regulation.  The alternator is told to make X amount of amps required to raise voltage to and hold  XX.XX volts, by the voltage regulator.
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That and the average temperature of the battery underhood.  Some vehicles have the battery insulated from direct engine heat, others no so much, or at all.  Batteries in some German vehicles are inside the trunk, and easily go 8 years before they will start cranking slower, noticeably.
<-------->
Truth is at 23 months of age it was seriously degraded, capacity wise, but it still worked at the task of engine starting, for 4 more years, and I rarley fed it with my solar.  Was mostly fed a diet of alternator 14.9 brevity followed by 13.7 for those 4 years, and Still could start my engine when I traded it for a core charge. on a new marine battery.

I wold like to see somebody that was crafty enough to eliminate the internal voltage regulator, and come up with an external programmable regulator to give us the option of charging how we want to.
The concept of a trunk mounted battery takes me back to my old hotrod days. We always mounted batteries in trunk for better weight transfer if possible. Also, other cars come from the factory that way. My Mazda Miata did, and my old box truck had a frame mounted battery, but the other one was still under the hood.
Now you point out another good reason to keep the battery out from under the hood. I'll have to keep that in mind.