Alternators and sense wires

[Loafer]

Hi Loafer,

 

If you want to sell your sterling reg pm me.

 

Neil.

 

I'm not sure if I want to let it go Neil, sorry. It's quite a big unit and has no sense or regulation wires going to either of my alternators. When in use, it takes both alternator outputs to the same input and 'fools' the alternator's own reg into powering up. Occasionally it stops 'boosting' and tops up the engine battery, before reapplying it's 'boost' to the domestic batteries. I disconnected it thinking it might be a bit excessive on my new Trojans.

 

Does the panel think It's ok to reconnect this device?

 

Anyway, thank you all for your replies. I'm not fit to do surgery on an alternator so I'll leave things as they are, and see what your opinions are regarding the reconnection of my alternator booster.

 

Just looked at it, its an AB12210 Alternator-to-battery charger.

[dmr]

All this messin' about with diodes and trying to break into the regulator sensing line sounds dodgy to me.

I'm an electronic engineer and I wouldn't try this sort of stuff.

Bite the bullet and fit a proper alternator controller. If you don't like the Sterling then buy an Adverc (which on balance is probably the better of the two).

In addition to controlling the voltage in a reliable way these will also provide temperature compensation which can be quite significant in the winter.

 

I suspect this diode stuff comes from Gibbo and was not one of his better ideas. He said "modern alternators don't need controllers at all so lets make one ourself with a diode???". I suspect this illogical thinking arose because he makes the Smartbank which is marketed as an alternative to alternator controllers and he was letting his desire to put down his competitors over-ride his engineering judgement.

 

And if you really like DIY and messing with alternators you could always design and build your own external controller, possibly based on an Arduino.

 

...............Dave

[OldGoat]

 

 

 

Just looked at it, its an AB12210 Alternator-to-battery charger.

 

Aha one of Charles' infamous (?) A to B units (mainly because I can't understand how it works - in a practical sense). The whole point of the unit is that doesn't require any messing about with the alternator - which other solutions do. If you look at his website, he clearly says that's what it's made for and even points out it's not necessarily the best solution. But he sells quite a number.

 

Somehow it manages to depress the 'seen' output voltage to persuade the alternator to provide more current. That implies to me some resistive load? That means heat is generated. Of course it could be some neat way of producing perpetual motion....

[David Schweizer]

 

 

The text I have highlighted in red shows that the wire you have in mind IS NOT the a sense wire. It is the wire by which the external controller shorts out the alternator's own controller. Disconnect that/those wires and the external controller simply stops working and control reverts to the alternator's voltage regulator. If it was a sense wire the alternator voltage would go uncontrolled (once the "bulk" phase is over) and the voltage would be solely dependant on revs. If it was a sense wire then the external controller would cause a short circuit and burn that wire, the field diodes, or the wire itself out as soon a sit tried to override the alternator's regulator.

 

This is the second time in this topic that a contributor seems to have misunderstood the purpose of an extra wire soldered to alternator brush connections. Once again - see post #11 - this is NOT a sense wire.

 

After the Lucas ACR and certain Paris Rhone designs of alternators there are not many that have an accessible sense connection inside the main body. You might be able to "misuse" the internal field diode (D+) to regulator connection to fool the regulator into thinking the charging voltage is lower than it really is but as I explained in post 11 this will also also reduce the rotor voltage and I do not know what effect that will have.

 

I have not misunderstood anything Tony, I know exactly what that wire is for. Our boat was used as the operational test boat for the prototype Sterling "Digital Advanced Regulator" Unfortunately your comments sound a little patronizing.

 

I will concede that the correct term for the wire on our set up is not a "sense wire" but the "field control wire". However, the OP was referring to a wire emerging from an alternator, which describes the field control wire, not a sensing wire.

Edited March 2, 2015 by David Schweizer

[by'eck]

 

Aha one of Charles' infamous (?) A to B units (mainly because I can't understand how it works - in a practical sense). The whole point of the unit is that doesn't require any messing about with the alternator - which other solutions do. If you look at his website, he clearly says that's what it's made for and even points out it's not necessarily the best solution. But he sells quite a number.

 

Somehow it manages to depress the 'seen' output voltage to persuade the alternator to provide more current. That implies to me some resistive load? That means heat is generated. Of course it could be some neat way of producing perpetual motion....

 

Simplest way to look at it is as a DC-DC converter - low voltage held on input (alternator side) - higher voltage suitable for fast charging on output (battery side).

[Loafer]

It seemed to do a good job but I was a bit worried about overcharging my new batteries.

 

Perhaps I shouldn't worry and wire it back in. At least I'll get 14.8V again!

[OldGoat]

 

Simplest way to look at it is as a DC-DC converter - low voltage held on input (alternator side) - higher voltage suitable for fast charging on output (battery side).

 

That makes good sense - I'd concentrated more on "how could you depress the sensed voltage in order to increase the alternator output" rather than the convertor function. Just the load presented on the Input side would do just that. There wouldn't be vast amounts of wasted heat either - just whatever losses there would be in the conversion process.

 

I'm quite happy to admit I'm a sort of a CS fan - he frequently sees a problem and comes up with a working solution. Such a shame that he doesn't suffer fools anyone gladly. If you grovel slightly he comes round somewhat.

 

It seemed to do a good job but I was a bit worried about overcharging my new batteries.

 

Perhaps I shouldn't worry and wire it back in. At least I'll get 14.8V again!

 

 

Didn't ano here recently added that after the magic bit had been performed the rest of the device then worked as a 'normal' battery management system. So you get a DC to DC converter coupled to a BMS:

Seemples (a bit dated now...)

[Loafer]

 

That makes good sense - I'd concentrated more on "how could you depress the sensed voltage in order to increase the alternator output" rather than the convertor function. Just the load presented on the Input side would do just that. There wouldn't be vast amounts of wasted heat either - just whatever losses there would be in the conversion process.

 

I'm quite happy to admit I'm a sort of a CS fan - he frequently sees a problem and comes up with a working solution. Such a shame that he doesn't suffer fools anyone gladly. If you grovel slightly he comes round somewhat.

 

 

 

Didn't ano here recently added that after the magic bit had been performed the rest of the device then worked as a 'normal' battery management system. So you get a DC to DC converter coupled to a BMS:

Seemples (a bit dated now...)

 

Do you mean a battery CHARGING system, rather than 'management'? I think it eventually goes to float if it's run for long enough.

[Tony Brooks]

 

I have not misunderstood anything Tony, I know exactly what that wire is for. Our boat was used as the operational test boat for the prototype Sterling "Digital Advanced Regulator" Unfortunately your comments sound a little patronizing.

 

I will concede that the correct term for the wire on our set up is not a "sense wire" but the "field control wire". However, the OP was referring to a wire emerging from an alternator, which describes the field control wire, not a sensing wire.

 

 

Well I have just scanned back through the thread and can find nowhere that the OP says anything about a wire emerging from an alternator. I can see where he asks about a sense WIRE and where he will find it. He neither specifies inside or outside the alternator. As far as I can see only two people decided the question was about the regulator bypass wire that has a totally different function to a sense wire.

 

I am sorry if it came across as patronising but it was, in my view, not what the OP actually asked about and it was the second instance of the misidentification being made in this topic, that is after I pointed out the error the first time. It concerns me when things that are downright misleading get repeated because many of our readers may all too easily get the wrong end of the stick from them.

[forsberg]

I would have thoght that any maufacturer of alternators would supply regulators both with and without a sense connection?

[Tony Brooks]

I would have thoght that any maufacturer of alternators would supply regulators both with and without a sense connection?

 

 

Well, you have thought wrong, despite that making sense. To do so would cost money - maybe 0.1p for a simple internal connection to to may be 2p for an external terminal, but then you have to realise that the alternators we tend to use are all automotive based, even though they may be painted black and carry a "marine" premium price. That means that over the world and over a year all those 0.1p add up to a great deal on money so it is not done. The second reason may be because connecting a sense lead while the internal D+ connection is in place would have no effect whatsoever so to do so would require the internal connection to be removed and that again costs money.

 

You might find a retail regulator with a sense connection but I rather doubt it unless a significant volume of battery sensed alternators are also in production. In the case of the Lucas A127 there is the "Tractor Regulator" that provides the facility to mess about with the regulated voltage but I ma far from sure it is in fact a battery sensed regulator. I can not speak for Iskara but all those alternators with regulator-brush assemblies that screw onto the back of the alternator that I know about only have a single connection for the D+ feed unless they are battery sensed machines.

[OldGoat]

 

Do you mean a battery CHARGING system, rather than 'management'? I think it eventually goes to float if it's run for long enough.

Methinks the terms 'charging' and 'mamanagement' are synonymous in discussions here - it being a general topic where there's a great deal of confusion and misunderstanding.

My point about CS' AtoB charger was - as reported on this thread and I did check on his website, that it is more than a charger, it performs equalization and related functions. I regard those as battery management?

I think he called it a charger, because he wanted to keep the idea simple - in effect beefing up the existing regulator function without tampering with the internals of the alternator. The product has been around for many years (ten perhaps?) and may well have transmogrified from a regulator replacement to something more complicated - as they say 'over time' (ugh!).

 

Does that make more sense? Feel free to disagree - discussion is one way to learn!

[Tony Brooks]

Methinks the terms 'charging' and 'mamanagement' are synonymous in discussions here - it being a general topic where there's a great deal of confusion and misunderstanding.

My point about CS' AtoB charger was - as reported on this thread and I did check on his website, that it is more than a charger, it performs equalization and related functions. I regard those as battery management?

I think he called it a charger, because he wanted to keep the idea simple - in effect beefing up the existing regulator function without tampering with the internals of the alternator. The product has been around for many years (ten perhaps?) and may well have transmogrified from a regulator replacement to something more complicated - as they say 'over time' (ugh!).

 

Does that make more sense? Feel free to disagree - discussion is one way to learn!

 

In my view calling anything from the Adverc, Kestrel, Sterling type of product a "battery management system" is juts plain wrong but that's what the marketeers call them and it has stuck. To actively manage batteries you not only need to manage the charging but also the discharging and none of them do that.

 

They and straight alternators are just charging systems of varying degrees of sophistication. I have never head a multi-stage mains charger referred to as a battery management system and they do much the same as these devices.

 

However as long as we all know what we are talking about and what they do we may as well humour the marketeers.

[Loafer]

Methinks the terms 'charging' and 'mamanagement' are synonymous in discussions here - it being a general topic where there's a great deal of confusion and misunderstanding.

My point about CS' AtoB charger was - as reported on this thread and I did check on his website, that it is more than a charger, it performs equalization and related functions. I regard those as battery management?

I think he called it a charger, because he wanted to keep the idea simple - in effect beefing up the existing regulator function without tampering with the internals of the alternator. The product has been around for many years (ten perhaps?) and may well have transmogrified from a regulator replacement to something more complicated - as they say 'over time' (ugh!).

 

Does that make more sense? Feel free to disagree - discussion is one way to learn!

 

 

 

 

No way do I disagree with you, Old Goat. I just wondered if you had a different product in mind.

 

It certainly manages the charging side of things, but it really makes alternators work hard!

[forsberg]

The second reason may be because connecting a sense lead while the internal D+ connection is in place would have no effect whatsoever so to do so would require the internal connection to be removed and that again costs money.

 

The ones I've came across have a resistor as the connection to D+, so no need to remove anything as a sense cable will have so low resistance that the influence of the resistor will be neglible.

It is also a safety future if the sense cable fails so the alternator dont run wild.

Marine alternators should also be ignition protected and not just painted black, not very important with diesels but still.

[by'eck]

 

 

No way do I disagree with you, Old Goat. I just wondered if you had a different product in mind.

 

It certainly manages the charging side of things, but it really makes alternators work hard!

 

Well call me a nit picker but the Sterling A to B doesn't, indeed can't make an alternator work harder than any battery load that depresses its output voltage below that of its regulating voltage. In other words it won't make a 100 amp alternator supply more than 100 amps.

 

What it does do is maintain the load on the alternator for longer than would happen if it relied solely on its own regulator, by holding the load voltage below that of its own regulator, when required. The result is closer to the alternators max output current is fed to the batteries for longer, reducing charge times. If inadequate fan speeds or poor design cause it to overheat that may be an issue, but it does have alternator temperature sensing to avoid this as well as a regular rest period during which time the boost is turned off.

 

ETA: Its been suggested that an engine manufacturers warranty may be invalidated by fitting such a device on a new fit. Such invalidation has no grounds though when you consider a large depleted battery bank could put close to full load on an unassisted alternator for a similar or longer period.

Edited March 3, 2015 by by'eck

[Neil Smith]

Is the jury for or against A to B chargers as I am considering one for the 140 and 50 amp alternators on my new barrus shire as I don't really want to mess with the alternators while still in warranty,

 

Neil.

[nicknorman]

Is the jury for or against A to B chargers as I am considering one for the 140 and 50 amp alternators on my new barrus shire as I don't really want to mess with the alternators while still in warranty,

Neil.

For a modern 140A alternator I don't see the need. Although I suppose it depends to some extent on how big your domestic battery bank is, but if it is say 440AH, for the vast majority of the time the batteries will be taking less than 140A. We have a 175A alternator and starting at say 60% SoC it is only maybe 10 minutes max before the current has dropped to 140A. If I crank up the Travelpower / Combi charger set to a high voltage as well, I do increase the charge current slightly, but maybe only by by 10 -15 A simply because the batteries don't want to take any more current. You can stuff a bit more current into the batteries when they are warm (summer) but then in summer we are more likely to start with batteries at 80% in the morning.

 

So in summary an AtoB does allow to keep a higher charge current for a longer, but by how much depends on the relationship between the alternator size and the battery size. Big alternator in average battery bank = no need for enhanced charging gadgets.

 

Put it this way, as you may have noticed I like my gadgets but I feel zero need to get something like this.

Edited March 4, 2015 by nicknorman

[Loafer]

Don't you think these AB devices are good because they follow a proper charge curve tho, rather than just keep 14.4v on all the time?

[nicknorman]

Don't you think these AB devices are good because they follow a proper charge curve tho, rather than just keep 14.4v on all the time?

Not for a canal boat, no. If you were going to run the engine 24/7 eg an oceanic cruiser then maybe, but keeping the charge voltage up at 14.6v or so for several hours after they are nominally fully charged is not bad for the batteries, in fact it's a good thing. How many threads do we get on here with folk who have overcharged thei batteries? We cruise long days but, when we had ordinary open lead acid batteries, virtually never needed to top them up (less than once a year).

 

On the other hand, we get loads of threads about folk under-charging their batteries. And issues with "intelligent" chargers etc deciding to go to float prematurely.

 

So no, it having a float mode counts against it in my book. Having a desulphation mode is a good thing, but you are paying a hell of a price just for that. Have you seen the prices of the A2Bs for large alternators?

[by'eck]

Don't you think these AB devices are good because they follow a proper charge curve tho, rather than just keep 14.4v on all the time?

 

Ceratinly an adavantage but note they offer a range of absorb/float voltages to suit various battery types up to a max I believe of 14.8 volts which its unlikely any built-in regulator will achieve. Once batteries fully charged they drop back to a safe float voltage, which would be an advanatge to those who cruise for long periods.

 

I considered fitting one to my boat when new, but rejected initially on the grounds of cost. Went instead for two Sterling DAR's which require the brush mod. This gave me independant control of alternators so allowing greater flexibility in how they were employed as well as saving money.

[dmr]

Is the jury for or against A to B chargers as I am considering one for the 140 and 50 amp alternators on my new barrus shire as I don't really want to mess with the alternators while still in warranty,

 

Neil.

 

I would think that fitting either a controller (with a wire fixed to a brush) or an "A to B" could void any warranty as you have changed the operating characteristic of the alternator. Controllers can make an alternator work quite a bit harder than intended so if the design is thermally marginal they could do damage. I have heard that Beta specify No controllers on their bigger alternators.

The advantage of the A to B is that if YOU remove a failed alternator and return it the supplier will not know that it had a controller fitted, though they will probably guess.

The A to B looks like a lot of power electronics just to avoid what is usually a very quick alternator modification.

 

.................Dave

[OldGoat]

 

Ceratinly an adavantage but note they offer a range of absorb/float voltages to suit various battery types up to a max I believe of 14.8 volts which its unlikely any built-in regulator will achieve. Once batteries fully charged they drop back to a safe float voltage, which would be an advanatge to those who cruise for long periods.

 

I considered fitting one to my boat when new, but rejected initially on the grounds of cost. Went instead for two Sterling DAR's which require the brush mod. This gave me independant control of alternators so allowing greater flexibility in how they were employed as well as saving money.

 

You're not the average boater and in a position to understand the pros and cons. The ordinary boater 'on the top of a Clapham Onmibus" just wants a solution - and that's usually just for one alternator.

For you and I the brush modification is quick and easy.

 

 

I would think that fitting either a controller (with a wire fixed to a brush) or an "A to B" could void any warranty as you have changed the operating characteristic of the alternator. Controllers can make an alternator work quite a bit harder than intended so if the design is thermally marginal they could do damage. I have heard that Beta specify No controllers on their bigger alternators.

The advantage of the A to B is that if YOU remove a failed alternator and return it the supplier will not know that it had a controller fitted, though they will probably guess.

The A to B looks like a lot of power electronics just to avoid what is usually a very quick alternator modification.

 

.................Dave

The inescapable truth is that standard automotive alternators are fitted to these packages and are not designed for running at high outputs for any length of time. Heavy duty alternators are very expensive.

 

Anyone considering a new build would be well advised to consider 24V units where there is a supply of high output heavy duty units.

[dmr]

 

You're not the average boater and in a position to understand the pros and cons. The ordinary boater 'on the top of a Clapham Onmibus" just wants a solution - and that's usually just for one alternator.

For you and I the brush modification is quick and easy.

 

The inescapable truth is that standard automotive alternators are fitted to these packages and are not designed for running at high outputs for any length of time. Heavy duty alternators are very expensive.

 

Anyone considering a new build would be well advised to consider 24V units where there is a supply of high output heavy duty units.

 

My own recent experiments and experiences certainly support this. Most alternators appear to have very "soft" regulators so go very rapidly into absorption mode, meaning that they only runs at full output for a short time. A controller keeps themt at full output for much longer so they just get hotter and hotter.

I know 24 volts has many advantages but 12v is still a lot more convenient.

I can see to other possible solutions.

One would be to fit alternators that are not working at their thermal limit. I suspect the 100amp or 120 amp versions of the popular large 175 amp alternator would be a lot more reliable.

The other would be an external controller that properly measures and limits maximum current, but I don't think anybody makes such a thing (at reasonable cost). This would allow a much more controlled output (and belt loading) over the speed range.

Essentially as you say, its not realistic to expect an alternator with a 100 amp rating to deliver 100amps continuously, especially at the lower end of its speed range.

 

..............Dave

[David Schweizer]

 

I would think that fitting either a controller (with a wire fixed to a brush) or an "A to B" could void any warranty as you have changed the operating characteristic of the alternator. Controllers can make an alternator work quite a bit harder than intended so if the design is thermally marginal they could do damage. I have heard that Beta specify No controllers on their bigger alternators.

The advantage of the A to B is that if YOU remove a failed alternator and return it the supplier will not know that it had a controller fitted, though they will probably guess.

The A to B looks like a lot of power electronics just to avoid what is usually a very quick alternator modification.

 

.................Dave

 

How long does the warranty last? Even with a controller an alternator will live for quite a few years, and if you avoid main dealers, replacements are not excactly expensive. We run our A127 alternator through a Sterling digital alternator regulator (controller) and typical life expectancy is something like four to five years. With replacements costing less than £50 (including delivery) and taking about half an hour to fit. it is hardly a deal breaker if the warranty is voided. I always keep a spare alternator on board with pulley and bushes already adjusted for quick replacememt,

 

I supopose some alternators will cost a lot more, but the fixings on many are fairly universal, so a cheaper and probably just as good alternative can always be fitted. I am also at a loss as to why people fit expensive double insulated "marine" alternators to an inboard engine on a narrowboat. My friend used to do that and his alternators lasted no longer than my bog standard road vehicle version whuich cost only a quarter of what he paid for his.

Edited March 4, 2015 by David Schweizer