High Rated Alternator with Alternator to Battery Charger

[goboatingnow]

Originally Posted by sailinglegend

Again you are showing your ignorance. The graphs I attached were from his LATEST book - yes it is 2005 - but he is describing modern Balmar Type external regulators. I have the 1996 version too which is very different.

You are always telling people they have mis-comprehended other's writings. You always know better - now even Nigel Calder is wrong!

There is no material difference between an internal regulator in bulk mode and an external one. if there is please explain what "magic" is being used. Both are regulating by controlling field current . what you are confusing are the differences in voltage regulating set point. In older automotive regulators that was often set quite low around 13.6-13.8V, What that had was to limit current into the battery after a certain point in bulk mode, because lead acid recovers terminal voltage quite quickly. This was a compromise between the power supply voltage for the car and the vagaries of charging sealed lead acid. This is less true in modern regulators where set points are higher.

But fundamentally all Balmar are doing is setting the absorption set point higher , that all they can do.

It cannot extract more power then the alternator can generate for example, nor can it "force" a battery voltage higher then the battery will allow ( all that would happen is that excessive current would flow, pulling the voltage down, generating surface charge and premature absorption set point).

Hence any regulator acting below its voltage set point can be said to be constant current ( even though that not specially true , its close enough)

what really happens is nothing like those curves in real life. Absorption point is not a "sharp knee". The set point of the regulator however is.


The fact is you have not shown us what specific difference there is between an internal regulator and and external regulator. This goes to the fundamental issue at the heart of the A2B versus external regulator debate in this thread.

dave

[colemj]

Originally Posted by goboatingnow

If you'd like to find me a "constant current " anything , that can maintain say a constant current into a 1000 Ah battery bank , I'd love to see it.

Constant current regulation into high current devices were very important in my old work. They looked like this:

Mark

[colemj]

Originally Posted by sailinglegend

now even Nigel Calder is wrong!

I didn't say he was wrong - just confusing.

This appears to be true.

Mark

[goboatingnow]

Originally Posted by colemj

Constant current regulation into high current devices were very important in my old work. They looked like this:

Mark

Yeap that what I mean, big mother f%^6k&rs

[colemj]

Originally Posted by goboatingnow

Yeap that what I mean, big mother f%^6k&rs

I've got one hooked to our OEM alternator right now - that sucker is pumping 1000 amps and powering my guitar amp.

Mark

[sailorboy1]

Originally Posted by colemj

I've got one hooked to our OEM alternator right now - that sucker is pumping 1000 amps and powering my guitar amp.

Mark

Yeah I thought that was you drowning out the sound of slapping halyards the other night

[Maine Sail]

Originally Posted by sailinglegend

Again you are showing your ignorance.

Sadly, it is the other way around. GBN and ColemJ are actually being very accurate.

[Ex-Calif]

Originally Posted by colemj

Actually, let me try this another way.

Do you agree that the only way to control the output of an alternator is to control the current on the field wire? Regardless of whether it is an internal or external regulator?

Yeah - I think everyone participating on this topic pretty much understands how the generating occurs.

The conversation goes quickly from "practical" understanding to scientific understanding.

I have been looking for any kind of graph that shows a typical field current vs. loaded alternator output. Haven't found anything useful that doesn't need a Phd. in "electrickery" to understand.

Originally Posted by goboatingnow

Both are regulating by controlling field current.

<snip>

The fact is you have not shown us what specific difference there is between an internal regulator and and external regulator. This goes to the fundamental issue at the heart of the A2B versus external regulator debate in this thread.

The heart of the "practical" matter...

Originally Posted by colemj

I didn't say he was wrong - just confusing.

This appears to be true.

Mark

I don't blame Calder - He assuredly knows his stuff but I think when you write a book (that you want a large number of people to buy) you have to put aside some of the scientific discussion, simplify the explanation so a broad audience can extract practical advice.

There is a limitation in books that I have harped about before - In that same 2006 edition Calder is crowing on about converting all lighting to fluorescent.

The Link 10 was cutting edge, GELS were "brand" new and LiFPo was in the future.

So books have their limitations.

In practical terms you want to push as many amps as possible into a battery - That creates lots of limitations as a result of the physics of the battery design.

Assuming a constant pulley speed (and ignoring some side effects caused by A/C charging) there is one alternator charging variable - field current.

[FlyingCloud1937]

Boys boys....

A "claw pole" alternator typical of all automotive style alternators, by design are A VOLTAGE REGULATED CURRENT SOURCE...Period

That means they are designed to provide a constant voltage at the required current demand of the design power requirements.

They were never designed as a current first, then voltage limited device.... Period.

This means they are not by design battery chargers. Each and every automotive alternator specked for an automotive design, is to provide a constant current, voltage regulated to an design onboard power system.

So that means when you install a bumping-thumping sub base wolfer sound system, into a factory design, that didn't include the sound system. YOU are taxing the system beyond warranty. In other words you will cause a brown-out on the design system.

Now that we got that straight, can an alternator be a battery charger by design???

The answer is yes, if by design.

NO, you can't just Willey-Nilley and alternator into a battery charger.

But you can create a battery charging system from an automotive style(Claw-Pole Alternator) if it's by design.

When you open the box of a standard automotive alternator, the first piece of paper you pull out, Will, state if the battery is less then 70% SOC, remove the battery to a external charger, and re-charge before install of the alternator...why??

Because, they assume that you purchased the alternator, that was specked by the design of the OEM power system.

go figger.....it's not a battery charger.

Now you expect a boat manufacture, whom spends as little money as possible on ----On-board Power Design--- to provide you with an automotive style alternator, that meets the requirements of a battery charger...

I say don't hold your breath.

That is what boating forums are about...everybody gets to say how they think an On-Board power System, should be designed, even if it's just hearsay.

Hell it doesn't cost anything, or does it???

Lloyd

[colemj]

Originally Posted by Ex-Calif

I have been looking for any kind of graph that shows a typical field current vs. loaded alternator output. Haven't found anything useful that doesn't need a Phd. in "electrickery" to understand.

It isn't too difficult - Maxwell described it and Tesla implemented it a long time ago. If you graphed amperage through a field coil vs. magnetic flux or dipole moment, you get a sigmoidal curve.

However, the majority of that curve, which is the part used for work, is linear - so for all intents and purposes, the relationship is linear. Put more current in, get more current out.

The slope of the field input/final output curve will depend on the alternator and winding design - but it will be linear in the range it is used.

Mark

[colemj]

Originally Posted by FlyingCloud1937

A "claw pole" alternator typical of all automotive style alternators, by design are A VOLTAGE REGULATED CURRENT SOURCE...Period

This is what many of us have been saying all along.

They were never designed as a current first, then voltage limited device.... Period.

Tell that to the alternator. When the battery voltage is below the regulator setpoint, it will provide all the current it can until that voltage rises enough. Then it starts to become voltage limited (through controlling the amount of current it provides). Have you seen one act differently?

Each and every automotive alternator specked for an automotive design, is to provide a constant current, voltage regulated to an design onboard power system.

I think you got this backwards. Automotive alternators are designed to have a constant voltage, with the current varying as needed to maintain that voltage. No alternator I know is set at a single constant current output.

But you can create a battery charging system from an automotive style(Claw-Pole Alternator) if it's by design.

All marine alternators are also claw-pole types and don't differ in any operational way than automobile alternators. I can't tell if you are making this distinction or not. The only physical difference between small automotive alternators and high-output ones are in the size of the windings, quality and number of fans, heat sinks, etc - but they operate using the same principles.

Mark

[transmitterdan]

The maximum power output of an alternator happens when the field voltage/current is at maximum. Since most (all?) regulators whether internal or external get their field voltage from the battery bus doesn't it mean the alternator current output is diminished when charging a 20% SOC bank because the available field voltage is reduced? And would it not also be the case that what Sterling does prolongs this condition more than an external regulator such as Balmar would? Sterling is "forcing" the alternator output voltage lower in an attempt to get more power out of it.

[colemj]

Originally Posted by transmitterdan

The maximum power output of an alternator happens when the field voltage/current is at maximum. Since most (all?) regulators whether internal or external get their field voltage from the battery bus doesn't it mean the alternator current output is diminished when charging a 20% SOC bank because the available field voltage is reduced? And would it not also be the case that what Sterling does prolongs this condition more than an external regulator such as Balmar would? Sterling is "forcing" the alternator output voltage lower in an attempt to get more power out of it.

I think most regulators, once started, get their field voltage/current from their own internal diode pack.

Besides, even a very low SOC battery bank has mucho capacity to power a field coil.

Mark

[sailinglegend]

Originally Posted by Maine Sail

Sadly, it is the other way around. GBN and ColemJ are actually being very accurate.

Thanks for joining the discussion, buy you haven't really added anything yet.

Yes a lot of what they say recently is very accurate, but in other posts they are providing 'opinions' not backed up by any fact or reference. I have at least tried to provided references which you and they don't approve. So in saying they are accurate then you are saying Calder and Sterling are inaccurate! So Mr Sterling's product literature is wrong and misleading also. That is a very serious allegation without any evidence from you.

The bottom line is it doesn't matter what happens inside whether it's constant current or not so constant, or what you want to call it. An auto alternator is no good at charging a deep cycle battery unless it has a high voltage set point which can be provided by an external regulator. I think we all agree on this.

[colemj]

Originally Posted by sailinglegend

An auto alternator is no good at charging a deep cycle battery unless it has a high voltage set point which can be provided by an external regulator. I think we all agree on this.

No, one of the points of this thread was that the A2B can also provide this without an external regulator or changing its internal regulator voltage set point. So far, you are the only one who has disagreed with that. Maybe Lloyd also - I wasn't clear on a couple of his points.

Mark