Help Installing My Sterling Alternator To Battery Charger

[demonboy]

Hello,

I have the task of installing my Sterling Pro Alt C 80amp alternator to battery charger (the link takes you to the instruction manual). Fortunately I can use all the current cables so it should be straightforward, but there are a few things puzzling me.

Currently I have a crappy alternator regulator and my Turkish electrician by-passed the internal regulator of the alternator to be wired to the external regulator. My first question is: can I just snip this wire to return the alternator back to its original state, or will I have to open up the alternator and rewire something? Here is a pic of the current alternator in situ which shows the by-pass on the top left of the alt and the pink wire that I mention below down the bottom-right of the alt:

Next, there appears to be some over-kill in my current wiring via the diode. I think an additional terminal has been used in order to cater for the wires that wouldn't fit on the diode. Do you think that is correct looking at this picture? The wires on the top terminal go to the alt and the diode, which is clearer in the schematic that I include, below.

Then I have additional cables that run from the diode and go to my mains battery charger, and there is a tiny pink wire that runs from the terminal to the alternator. You can just make out the thin pink cable in both the above images. Here is a schematic of what I can currently see:

The idea of the new unit is that I get rid of the diode, so my questions are:

1. As above (can I snip those wires on the alt to return it to the original state)
2. Is the top terminal just a terminal or is it doing anything else?
3. Where do the yellow/green mains battery charger cables go?
4. What is the thin pink cable? Is it a 'common negative'?

Any help gratefully received, thanks.

 

[SvenglishTommy]

Are you sure that schematics is right? It looks like the diode is being bypassed for the engine battery. The thin pink wire is most likely a sense wire for the current alternator, it looks too small to be the negative - and would be shorting the circuit if it was.

 

[VicS]

Revised post:-

The small pink wire I think must be a sensing wire.

Are those two terminals on the extra terminal block connected to each other or not? Hopefully not!

You need the alternator to be machine sensed. It looks as though it has been converted to battery sensing in order to overcome the volts drop across the diodes.

It should be sufficient to connect it to the alternator output but it might be better to return the alternator entirely to its original configuration.
No reason though why it should not use an external regulator if the original is defunct and has been removed or disconnected.

The alternator must be working correctly before installing the AB charger

Reference to the instructions for the AB charger at http://www.sterling-power.com/image...or-to-Battery Chargers and Remote Control.pdf should help.

Read and study before starting the installation.

I am not sure I am making sense of your wiring of the diode splitter but no matter you will not need it. With the AB charger it is redundant and can be discarded. Disconnect it and remove it entirely

If the alternator is performing correctly with the external regulator then retain that.

Take the main +ve output from the alternator to the connection shown on the AB charger.

Connect the AB charger outputs directly to the two batteries as shown..

Note a small negative connection is also needed from the alternator to the AB charger.

Thats all as far as the AB charger is concerned Simplicity of installation is one of its virtues.

I guess you are indicating that you have a mains charger with dual outputs. Connect one to each battery and connect the negative to the common negative busbar.


The black wire on the W terminal is the signal to the rev counter hopefully?

The other smallish red wire is the connection to the warning light ???

 

[demonboy]

Thanks for the replies. Some further comments following on from your instructions:

1. Pink wire. I guess it must be a sensing wire so when I disconnect the diode, which is where it is currently attached, where does it go after that? From the alternator to where?

2. What do you mean by machine-sensing the alternator? Both alternators (installed and spare) were serviced in Turkey. Does that count? After motoring some 2,000 miles would it be prudent to get them serviced again?

3. The external regulator is being decommissioned because it is rubbish. Indeed this is why the Sterling is being installed, as a replacement.

4. So now the mains charger is directly connected to the batteries as opposed to the diode. The new AB is also connected to the batteries. That means the mains charger and the AB may be connected to the same terminal, yes? The AB has a built-in diode, or some circuit that negates the need for one, so would it be safe to wire the two together?

 

[SvenglishTommy]

1. Pink wire. I guess it must be a sensing wire so when I disconnect the diode, which is where it is currently attached, where does it go after that? From the alternator to where?

Is this wire not going to the external regulator that is being deomissioned? If so it will get decomissioned with it

2. What do you mean by machine-sensing the alternator? Both alternators (installed and spare) were serviced in Turkey. Does that count? After motoring some 2,000 miles would it be prudent to get them serviced again?

I wouldn't, if it aint broke dont fix it. Machine sensing is the 'normal' method alternators use to regulate their output, putting a diode in the way drops the voltage, so the sense wire needs to on the battery side of the diode so it is sensing the real voltage - your new toy manages all this now.

4. So now the mains charger is directly connected to the batteries as opposed to the diode. The new AB is also connected to the batteries. That means the mains charger and the AB may be connected to the same terminal, yes? The AB has a built-in diode, or some circuit that negates the need for one, so would it be safe to wire the two together?

Yes

 

[demonboy]

Excellent stuff. I think I am ready to attempt this job and blow my system up

Of course I have simplified the schematic as the diode does not go directly to the batteries; instead it goes to a switching unit (1-2-ALL), which is another thing altogether. Not entirely sure that was ever wired correctly but that's another thread.

Thank you both for your input.

 

[demonboy]

Sorry, I forgot to ask one final question: what is 'common negative'? The instructions say "ensure all negs are common". Does this mean the house and starter batteries are all connected directly via one negative between them and the AB unit?

 

[SvenglishTommy]

Of course I have simplified the schematic as the diode does not go directly to the batteries; instead it goes to a switching unit (1-2-ALL), which is another thing altogether. Not entirely sure that was ever wired correctly but that's another thread

This could be scewing up the whole the setup, the whole point of the diode is to isolate the batteries from each other, if they're going through a 1-2-ALL switch, you're just paralleing them again. With this kind of setup (diode or alternator charger) you would normal have seperate isolation switches for each battery.

Common negative means that they're all connected together.

 

[VicS]

1. If the pink wire is a sensing wire then I think it could be connected to the alternator main +ve output terminal instead of to the diode. (I'd like to see some agreement from other forumites though esp from someone like Halycon)

2. Mostly alternators are "machine sensed". They sense the volts within themselves in order to produce the correct volts at the output.
When you fit diode splitters, because they introduce a voltage drop it is desirable to modify the alternator to sense the volts at the battery. It then maintains the correct volts at the battery despite the effects of the diode splitter
I'd not like to comment on the advisability of servicing the alternators. Your call, but is a good opportunity to do so perhaps and convert back to machine sensing at the same time

3. The Sterling AB charger does not replace the alternator's own regulator. Your alternator and existing regulator must be fully functioning before fitting it.
It is not a regulator. It is in effect a split charging device that uses advanced electronic jiggery pokery to produce enhanced charging of the domestic battery at the same time as normal charging of the starter battery.

4. The mains charger should be wired to the battery. If its a dual output, which is what your diagram appears to show, then one output to one battery and the other output to the other battery. There is no indication in the instructions that this should not be done.

 

[VicS]

Excellent stuff. I think I am ready to attempt this job and blow my system up

Of course I have simplified the schematic as the diode does not go directly to the batteries; instead it goes to a switching unit (1-2-ALL), which is another thing altogether. Not entirely sure that was ever wired correctly but that's another thread.

Thank you both for your input.

Oh dear! That put a different complexion on the whole thing

Lets see how this is wired. You don't want a switch that will connect both batteries together when you have an AB charger. In fact its not even really appropriate to use with a diode splitter.


You need to sort out the whole shooting match.

Have we been over this before?

You also need to show us how it really is all wired, not miss bits out.

If your system is such that it relies on a 1,2, both, off switch you will either have to separate engine electrics from domestic electrics OR perhaps use one of Sterlings Digital advanced alternator regulators rather than the AB charger

 

[SvenglishTommy]

VicS has a good point there, you need to make sure it is functioning normally before adding the charger, either by returning the alternators to their original self regulating, or by leaving the existing external regulator intact.

I also think that you would connect the sesning wire to the +ve, and I think that's what I did in mine when I installed an advanced regulator on my battery sensed alternator.

 

[SvenglishTommy]

...perhaps use one of Sterlings Digital advanced alternator regulators rather than the AB charger

Don't they still need the banks to be isolated?

 

[VicS]

Don't they still need the banks to be isolated?

Well, yes and no!

The advanced regulator simply controls the alternator output to give the enhanced charging regime. You just have the one output from the alternator + terminal, not the twin outputs of a AB charger

You can then use either a 1,2, both switch or a diode splitter (or I suppose a vsr) in the usual way

There are wiring diagrams in the on line instructions to show how to wire for either of these arrangements.

I was thinking that with a diode splitter already installed and a sensing wire already fitted to the alternator the advanced regulator might have been an attractive option rather than the AB charger.

 

[demonboy]

OK, tomorrow (it's 8pm here now) I'll put together an improved schematic. Thank you.

 

[mjf107]

Oh dear! That put a different complexion on the whole thing

Lets see how this is wired. You don't want a switch that will connect both batteries together when you have an AB charger. In fact its not even really appropriate to use with a diode splitter.


You need to sort out the whole shooting match.

Have we been over this before?

You also need to show us how it really is all wired, not miss bits out.

If your system is such that it relies on a 1,2, both, off switch you will either have to separate engine electrics from domestic electrics OR perhaps use one of Sterlings Digital advanced alternator regulators rather than the AB charger

Agreed, simply follow the A-b instructions.............Ensure the alternator is working correctly and make sure its configured to machine sense see note on page 3

Remove split charge diode and fit A-B in its place page 3 . Wire as diagram on page 8.

As the diagram does not show 1-2-both control I would remove if fitted, thus eliminating the problems associated with these devices. It would be advisable to fit battery isolators although the drawing does not show them.

Michael

 

[demonboy]

OK, guys, you're starting to confuse me.

I am installing the AB in replacement of the external regulator. Why are you suggesting I keep it installed? I don't understand why I would want both. [For the record the external regulator is a piece of cheap rubbish that is impossible to set correctly. It is unable to cope with fully-charged batteries by bouncing (fluctuating) the voltage from the alternator, but that's another story.]

Secondly, why would I want to remove the 1-2-All switch? I use this to swap between the starter battery to start my engine, and then switch to the house batteries afterwards. By removing this switch I have no control over this, do I?

I am still drawing up the schematic, btw. It's taking rather a long time as it's quite involved.

 

[VicS]

OK, guys, you're starting to confuse me.

I am installing the AB in replacement of the external regulator. Why are you suggesting I keep it installed? I don't understand why I would want both. [For the record the external regulator is a piece of cheap rubbish that is impossible to set correctly. It is unable to cope with fully-charged batteries by bouncing (fluctuating) the voltage from the alternator, but that's another story.]

Secondly, why would I want to remove the 1-2-All switch? I use this to swap between the starter battery to start my engine, and then switch to the house batteries afterwards. By removing this switch I have no control over this, do I?

I am still drawing up the schematic, btw. It's taking rather a long time as it's quite involved.

The Sterling AB charger does not replace the alternator regulator. It is purely an add on split charging device that, by utilising electonic jiggery pokery, gives simultaneous enhanced charging of the domestic battery and standard charging of the starter battery.
Read the over view in the instruction manual

You need to get your alternator performing properly with its own regulator before you fit the AB charger. If the external regulator is rubbish get a proper one fitted.
If its just an addition then remove it but get the alternator running properly on its own regulator

You can keep your 1,2,both switch if you want but surely with separate and different charging regimes for the two batteries the way forward is to separate the engine and the domestic electrical systems, feeding each from its own dedicated battery via separate isolating switches.

However show us how it is all wired at present then we know what suggestions to make.

 

[demonboy]

OK, this is the best I can do without ripping up floor-boards and panels. There are a lot of cables in identical conduits disappearing down the same holes so it's nigh-on impossible to know which is which, but some assumptions can be made. Also the previous owner kindly labeled one or two cables, so currently the schematic shows the stuff I know for certain. I have avoided adding things that are directly connected to the house batteries, like solar panels, fridges and water-maker. They all happen after the diodes, switches and terminals so I figured they are irrelevant for this exercise.

There are, however, some unknowns, which may be deduced by elimination I guess. For example, there are three neg cables coming off the engine battery - where do they go? I am assuming one has to be windlass and is one the the common negative? Do I need to know that for this exercise?

I can see how I can wire in the AB but what is throwing me is that by doing this I lose my ability to start the engine with the domestic and run my domestic electrics with the engine and use both together for the windlass.

Anyway, here's the schematic. As you can see in the bottom left there is a cable that has been labeled 'engine start', but I am unsure where this is from, and you'll note the domestic isolation switch has not been used at all.

Also, perhaps you could explain why you are still recommending I keep or replace my external alternator regulator. The product spec says "all the performance of an advanced alternator regulator without all the fitting". That is why I am replacing my rubbish external regulator with this this thing:

1. It charges faster
2. It by-passes the need for the diode, which is taking out 0.8v charge in my current system
3. It regulates the charge going into the battery

With this is mind, why do I still want my external regulator?

 

[mjf107]

[/QUOTE]
Also, perhaps you could explain why you are still recommending I keep or replace my external alternator regulator. The product spec says "all the performance of an advanced alternator regulator without all the fitting". That is why I am replacing my rubbish external regulator with this this thing:
[/QUOTE]
1. It charges faster
2. It by-passes the need for the diode, which is taking out 0.8v charge in my current system
3. It regulates the charge going into the battery

With this is mind, why do I still want my external regulator?[/QUOTE]

I'm beginning to see your confusion and I sympathise, but the simple fact is A-B is not a alternator regulator as such, it modifies the output from the alternator and ensures the domestic bank is fully charged and the start battery charged normally, which is considered adequate for engine starting. The 2 batteries are kept separate so there is normally no need to combine them for engine starting as you will always have the engine battery fully charged.

In my original response I wrongly assumed your electrical was of a more basic nature. You need to asses all your electrical loads to make sure you have adequate battery capacity. The way your operating the winch from both batteries is not a good idea in my opinion, it would be better to have a larger domestic bank or a dedicated battery, but this is going to complicate things even further

Michael

 

[VicS]

Also, perhaps you could explain why you are still recommending I keep or replace my external alternator regulator. The product spec says "all the performance of an advanced alternator regulator without all the fitting". That is why I am replacing my rubbish external regulator with this this thing:

1. It charges faster
2. It by-passes the need for the diode, which is taking out 0.8v charge in my current system
3. It regulates the charge going into the battery

With this is mind, why do I still want my external regulator?

You need a fully functioning alternator and regulator because the AB charger does not replace the regulator.

It is not an alternator regulator. It is an add on split charging device.
It replaces, and improves upon, the diode splitter.
By cunning electronic means it gives enhanced and regulated charging of the domestic battery.


An alternator regulator works by controlling the current supplied via the brushes and slip rings to the field coil.

The AB charger doe not do that. There is no connection to the field circuit, just a connection from the main output terminal!
Look at the wiring diagram in the installation instructions!


I'll look at your diagrams later.

First impression is that your diode splitter is wired incorrectly and as a result giving poor charging of the domestic battery. Since the AB charger will replace it it is not now important but it does mean that your charging could have been improved to some extent without the expense of the AB charger!

I do not at the moment understand the wiring of the 1,2 both switch.
Is this the type of switch which rotates fully ( ie from "off" to 1, then to "both", then to "2" and finally to "off" again) or something different

Also can you advise if the "terminal", top centre of you diagram, actually connects all the wires shown going to it, or is it two separate terminals insulated from each other.