Help Installing My Sterling Alternator To Battery Charger

[demonboy]

It is not an alternator regulator. It is an add on split charging device.
It replaces, and improves upon, the diode splitter.

OK.

Look at the wiring diagram in the installation instructions!

I have, and it's quite straightforward, but someone mentioned that having the 1-2-All switch in the circuit changes everything, so what looked like a simple installation is now a bit more confusing.

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!

Yes, the diode is definitely a problem BUT wihthout the AB don't I need it to protect my circuit?

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)

No, it doesn't rotate fully. From right to left it goes "Off-1-ALL-2". If on '2' then you have to turn back clockwise to go back to the OFF position. And I have never been convinced that it or the isolation switches have been wired correctly either. The way I was taught to use them was to switch to 1 when starting the engine, leave on 1 for windlass, switch to All when charging for a bit, then over to 2 to keep charging the house batteries, leaving 1 alone and only ever using for engine start. I'm not sure if the switch is supposed to designate what charge goes where, or if it's to designate what gets used for power, or both.

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.

'Terminal' may be the wrong term, so apologies for the confusion. There are three bolts going to it but it is difficult to work out by looking at them if they are isolated from each other. They look like they are all part of the same bar. See the picture I included (pictured top):

What quick test could I do with the volt-meter?

@Michael - I don't use my house batteries with the starter battery for the windlass but I have got used to having it as an option, which the 1-2-All switch offers. If installing the AB means losing the 1-2-All switch then I'm happy to do this.

 

[VicS]

Thanks for clarification.

I'll get back to you later. There are things I must get on with. Not least of which is getting myself some lunch.

 

[SJF]

Here is a diagram of my proposed upgrade to a Sterling Alterntor to Battery charger which may assist you with comparing what you have. My proposed plan was to remove my existing Off-1-Both-2 switch for the three switches shown in the diagram below.

It's only my initial plan/overview of what I'm planning to do at some point in the future so I hope it helps rather than adds to the confusion but I thought it may help you figure out what some of your existing connections are/could/need to be.

 

[SvenglishTommy]

No, it doesn't rotate fully. From right to left it goes "Off-1-ALL-2". If on '2' then you have to turn back clockwise to go back to the OFF position. And I have never been convinced that it or the isolation switches have been wired correctly either. The way I was taught to use them was to switch to 1 when starting the engine, leave on 1 for windlass, switch to All when charging for a bit, then over to 2 to keep charging the house batteries, leaving 1 alone and only ever using for engine start. I'm not sure if the switch is supposed to designate what charge goes where, or if it's to designate what gets used for power, or both.

Just to help you understand the issue with this switch, the idea of using a split charge diode, or the A-B charger, and your multi output battery charger is that the battery banks are completed isolated from each other at all times. This means you dont need to touch any switches, as the engine battery is always connected to the engine, and the house bank is always connected to the house. Both batteries are charged independently at all times, by the A-B charger or your mains charger.

Your 1-2-both switch is giving you 3 options, none of which you want to use. You would normally just have a seperate isolation switch for each battery, when you get on board you turn them on, when you leave you turn them off - no need to switch anything while you're on board, it's all automatic, which is the beauty fo this set up.

 

[demonboy]

Your 1-2-both switch is giving you 3 options, none of which you want to use. You would normally just have a seperate isolation switch for each battery, when you get on board you turn them on, when you leave you turn them off - no need to switch anything while you're on board, it's all automatic, which is the beauty fo this set up.

Understood. I have those isolation switches, one of which isn't even wired up.

@SJF - thanks for that. Any chance you could email me the original? I'll PM you with my email address.

@Vic - I appreciate your time on this. It's a learning process for me and unfortunately I'm on my own here in Cochin. There just isn't the expertise on these systems so it's just me and Calder, I'm afraid Also just bear in mind I am 5.5 hours ahead of you so there may be some delay in replies. I'm sure you are a busy man so I'm grateful of whatever help you can offer, as ever.

Thanks to all of you so far.

 

[SJF]

@SJF - thanks for that. Any chance you could email me the original? I'll PM you with my email address.

Email reply sent and forum image size slightly increased.

 

[SvenglishTommy]

That's a very nice diagram by the way SJF. Demonboy, you might to include the 'emergency parallel' switch as well like SJF has in his diagram. This is a useful feature, and basically gives you back the 'both' mode for use in emergencies, e.g. if you want to start the engine from the house bank, or watch a movie from the engine bank

 

[VicS]

Ive had a bit of a look at your wiring diagram.

It seems likely that you diode splitter is incorrectly wired

I think your 1, 2, both switch merely allows you to start the engine from either the starter battery or the domestic battery or both.

I can see nothing wrong with SJF's proposal ... saved me drawing something similar!

Separate battery isolating switches plus a third switch to link the domestic and engine circuits allow you to use either battery for either purpose or to use them in parallel should the need arise.
Do away with the 1,2,both switch as it will no longer be needed

You appear to have a battery charger with two outputs. Connect one output directly to one battery and the other to the other battery.

You will still have to sort out the funny regulator you have on your alternator and connect the sensing wire to its main output or have it properly converted back to machine sensing.

 

[mjf107]

Here is a diagram of my proposed upgrade to a Sterling Alterntor to Battery charger which may assist you with comparing what you have. My proposed plan was to remove my existing Off-1-Both-2 switch for the three switches shown in the diagram below.

It's only my initial plan/overview of what I'm planning to do at some point in the future so I hope it helps rather than adds to the confusion but I thought it may help you figure out what some of your existing connections are/could/need to be.

Nice drawing but there is a mistake on it. The alternator return current is bypassing the shunt. All domestic loads from the battery and alt should go via the shunt. As it is the BM-1 will only show discharge and not register charge current. Does this sound familiar VicS? You only need to remove one link (the horizontal to the left of the always-on devices and reconnect it to the other side of the shunt). I cannot do a drawing as I am not at home.

Michael

 

[pvb]

Nice drawing but there is a mistake on it. The alternator return current is bypassing the shunt. All domestic loads from the battery and alt should go via the shunt. As it is the BM-1 will only show discharge and not register charge current. Does this sound familiar VicS? You only need to remove one link (the horizontal to the left of the always-on devices and reconnect it to the other side of the shunt). I cannot do a drawing as I am not at home.

No, you're wrong about that.

 

[SJF]

Nice drawing but there is a mistake on it. The alternator return current is bypassing the shunt. All domestic loads from the battery and alt should go via the shunt.

As far as I can see all loads from the batt and alt do go via the shunt to the domestic bank as the shunt is the only item connected to the negative terminal of the domestic bank (as per the nasa instruction manual).

As it is the BM-1 will only show discharge and not register charge current.

This surprises me, I actually have the BM-1 Compact and that definately show both charging and discharging current.

You only need to remove one link (the horizontal to the left of the always-on devices and reconnect it to the other side of the shunt).

If I remove the link as you suggest above, where will my 'always on' devices get their positive supply from? If I connect it to 'the other side of the shunt' I will have connected 2 negative supplies which will clearly not power any of my devices.

Afraid I agree with pvb's comment.

Simon

 

[VicS]

Nice drawing but there is a mistake on it. The alternator return current is bypassing the shunt. All domestic loads from the battery and alt should go via the shunt. As it is the BM-1 will only show discharge and not register charge current. Does this sound familiar VicS? You only need to remove one link (the horizontal to the left of the always-on devices and reconnect it to the other side of the shunt). I cannot do a drawing as I am not at home.

No I am afraid the diagram is correct.

Nothing except the shunt should be connected to the domestic battery negative, and nothing except the wiring for the BM1 itself should be connected to the battery end of the shunt.

I think I am going to ask for this diagram

to be made a sticky​

 

[mjf107]

My mistake please accept my apology and explanation

Nice drawing but there is a mistake on it. The alternator return current is bypassing the shunt. All domestic loads from the battery and alt should go via the shunt. As it is the BM-1 will only show discharge and not register charge current. Does this sound familiar VicS? You only need to remove one link (the horizontal to the left of the always-on devices and reconnect it to the other side of the shunt). I cannot do a drawing as I am not at home.

Michael

Please ignore the above I now believe the drawing to be correct

Just as my head was hitting the pillow last night my mistake dawned on me. In my own defence I had it partly right, the current flowing through the loads from the alternator does indeed by pass the shunt BUT I over looked the fact that any surplus current will be available to charge the domestic battery, returning to the alternator via the shunt. The magnitude of this current would of course be limited by the charge acceptance of the battery and register correctly on the BM-1

Please accept my apologies I'm going to stand in the corner for 10 minutes and reflect

Michael

 

[demonboy]

I'm happy to report that I have at least ensured all my negs go to the bus bar, Vic. That something I've done right.

Now, fuses. Can someone tell me about these please? What sizes? Are they a particular type? I'm not sure I have fuses outside of the control panel...

Also, going back to Vic's question about the connection in this picture:

Does this look like a bus bar for some extra positive connections? I don't understand why they have gone to this when they could have connected directly to the diode. Is it something to do with the sensor having to connect to the alternator before the diode?

Also, the diode has three connections on it. Is the diode doing something different to each connection or do they all connect? If they all connect then aside from the sensor there appears to be no reason for that extra bar above the diode.

Finally, Simon's diagram has the distribution panel before the isolation switch. My current set-up has it after the isolation switch. Does this make a difference or is this just the nature of a correctly drawn circuit diagram?

 

[VicS]

Two things to bear in mind with fuse ratings.

• Obviously they must be adequate to supply the maximum current any circuit will require. Remembering that some things esp those with electric motors involved my take a higher current when starting than they do when running.
• They should be chosen so that the rating is less than the max safe current rating for any wiring they supply. So that the fuse blows in the event of a fault rather than the wiring overheat

.

The diode splitter is only of academic interest if you are replacing it with an AB charger but its circuit is

Current only flows in the direction of the arrows. ie from the alternator to each of the batteries. It cannot flow backwards from either battery and so prevents one battery feeding the other.
You see my diagram shows the alternator connected to the middle connection. Compare that with your diagram and I think you will see why I think yours is incorrectly wired.

Simon's diagram shows the main distribution panel after the isolation switch, starting from the battery. That is how it should be. Once the switch is opened the battery is disconnected from everything except those items connected to his "always on bus" and the battery charger.


I suggest you take a bit of time to study the "Boat Electrical notes" at TB-training before moving on to Calder's book. They give a simple explanation of all the basics.

 

[VicS]

Please ignore the above I now believe the drawing to be correct

Just as my head was hitting the pillow last night my mistake dawned on me. In my own defence I had it partly right, the current flowing through the loads from the alternator does indeed by pass the shunt BUT I over looked the fact that any surplus current will be available to charge the domestic battery, returning to the alternator via the shunt. The magnitude of this current would of course be limited by the charge acceptance of the battery and register correctly on the BM-1

Please accept my apologies I'm going to stand in the corner for 10 minutes and reflect

Michael

The point is that the shunt is used to measure the current being drawn from the battery, the load, or the current flowing into the battery, the charge, hence it is between the battery terminal and everything else.
Whichever way the current is flowing it goes through the shunt because there is no other route.

We'll leave you in the corner until the end of the lesson

For extra homework read Tony Brook's notes.

 

[pvb]

You see my diagram shows the alternator connected to the middle connection. Compare that with your diagram and I think you will see why I think yours is incorrectly wired.

I think that the diode splitter in the photo is the stand-alone version of one which was designed to fit directly on the back of the alternator. The direct fitting unit picked up the alternator output by being bolted to the B+ post (top right hole in the following pic)

With the stand-alone unit, the diode pack was bolted to a bracket, and an input terminal added in the top right (see next pic)

You'll need to rotate the unit 90 degrees anticlockwise in your mind to match the OP's photo.

 

[VicS]

I think that the diode splitter in the photo is the stand-alone version of one which was designed to fit directly on the back of the alternator. The direct fitting unit picked up the alternator output by being bolted to the B+ post (top right hole in the following pic)


With the stand-alone unit, the diode pack was bolted to a bracket, and an input terminal added in the top right (see next pic)


You'll need to rotate the unit 90 degrees anticlockwise in your mind to match the OP's photo.

That sort of thing did cross my mind. Volvo, and presumably others, used them on the alternators but I did not know there was a stand alone version. Bound to be I suppose
If that's what it is then it is wired correctly !
The two connections on the "terminal" are separate and the alternator is sensing the engine start battery via the pink wire.
That all seems more logical.

Would you agree that the pink wire could simply be connected to the main output terminal to make it machine sensed?

 

[pvb]

Would you agree that the pink wire could simply be connected to the main output terminal to make it machine sensed?

I'd imagine that would work.