STERLING ALTERNATOR TO BATTERY CHARGER

[GUMPY]

I don't work for anyone and have no connection at all with any of the boat equipment manufacturers. I was a very lucky, successful business person who managed to float a "dotcom" company at the height of the "gold rush" in 2000 and cashed out big time.

 

Thank you for that just needed to be clarified

 

J

[Prof]

Our boat is two and a half years old, fitted with an Isuzu 4BL33 with two 70 amp alternators.

Within a month on delivery I fitted a Stirling alternator to battery charger and a Sterling 1.8 Kw inverter. The setup works brilliantly! I have never in 43 years of boating had a boat with such well charged batteries, I check the 3 x 135ah domestic + 1 x 110ah engine battery for electrolyte level regularly but find they use no more than usual (very little!).

If I run a high demand electrical item like a vacuum I run the engine whilst in use and you can hear the "grunt" as the vacuum is turned on; but no signs of trouble with belts so far, (maybe because I've got spares on board)

I use a clip-on ammeter to check charge from each alternator, and input to the inverter from time to time and so far all is as you'd expect.

If you have any questions I've found Charles Sterling very approachable, knowledgeable and helpful (I'm not associated with Stirling either!) PLUS if you live anywhere near Worcester you can get some very good discounts by a personal visit with "the readies".

I was initially unsure but 2.5 years say it was a very good investment to get peace of mind and 50% more useable battery power.

 

GO FOR IT

[chris w]

I agree with you about Sterling products and Charles Sterling. He is very happy to have a "white board" debate if you visit and go into a lot of depth about the products. He gave me a discount of 20% on £1400 worth of his kit (a nice saving). They will also take credit cards despite their not being a "shop".

 

I had one small problem, paradoxically on the most simple item (an AC switch ~£40) but they posted a new one to me and told me to keep the original too (which only had a small problem with the plastic knob).

 

His website sterling-power.com is a veritable mine of good information.

 

Chris

[Lesd]

The sterling alternator to battery charger basically does the same job as their external alternator regulator (i.e. enhanced 3 stage charging), but without the need to bypass the alternator's own regulator, which means it's easier to fit and maintains any warranties.

 

However, I don't think anyone has mentioned that while on older alternators these devices work to increase output, on modern marine alternators which already put out over 14v, they may not actually do anything.

 

http://www.smartgauge.co.uk/controllers.html

 

 

Thanks for all your replies further up the thread regarding overcharging.

 

Having read Blackroose's comment above and bearing in mind John's point regarding redundancy my dilema becomes which of these two options to go for;

 

1. 50a alternator dedicated to starter/bow thruster battery. 160a alternator dedicated to 540ah domestic bank (possibly via an external alternator regulator to maximise batt charge and minimise charge time)

 

or

 

2. Use Sterling ''battery to alternator'' device to combine both alternators outputs to charge all batteries 'in parellel' (probably not technically the right term). I assume this would give a shortr chanrge time compared to option 1 above ? But I loose my alternator redundancy.

 

Any views ?

[NB Alnwick]

Has anyone had any experience with the 'Adverc' battery management device?

 

Our boat generates all the power we need from an ancient C.A.V./Lucas 24 volt, 70 Amp alternator which probably had a previous life on a bus or coach. The two starting batteries (cold cranking a Kelvin K3 draws a lot of power) and four cabin batteries appear to be sufficient for our needs and we only have to revert to our small portable generator when the engine has been idle for three or four days. Domestic 230 volt power is provided by a Sterling 1800 inverter which seems quite sufficient for our TV, DVD, computer and occasional use of the vacuum cleaner, spin dryer and power tools.

 

Many experienced boaters have given us completely conflicting advice on the 'Adverc' - one camp says "disconnect it - it will burn out your alternator" whereas the other camp says "keep it connected - it is the only way to charge your batteries properly" . . .

 

Is the 'Adverc' unit similar in function to the 'Sterling Alternator to Battery Charger' - does anyone have any views?

[Keeping Up]

Has anyone had any experience with the 'Adverc' battery management device?

...

Many experienced boaters have given us completely conflicting advice on the 'Adverc' - one camp says "disconnect it - it will burn out your alternator" whereas the other camp says "keep it connected - it is the only way to charge your batteries properly" . . .

 

Is the 'Adverc' unit similar in function to the 'Sterling Alternator to Battery Charger' - does anyone have any views?

It is similar in that it is designed to make the alternator work much harder and to charge your batteries fully (or more nearly so). It differs in that it drives the alternator itself, thus requiring a wire to be connected inside the alternator, instead of 'fooling' the internal workings of the alternator into driving themselves harder.

 

We have had one fitted for over 10 years, and (from the point of view of an experienced electrical engineer) it has always worked perfectly. I have nothing but praise for it (and also for Adverc's technical department).

 

Many people will tell you that it 'burns out your alternator'. This is NOT true. However it will create the conditions under which the alternator can burn itself out; exactly the same applies to the Sterling unit. In both cases they cause the alternator to work very hard, often running flat-out for a long period of time. Most alternators are quite happy to do this provided they are adequately cooled, which means they must have a good supply of cool air. In an open engine-room this is not usually a problem, but in an enclosed space such as under the deck of a cruiser stern there may not be enough cool air available.

 

Let me illustrate this. Two years ago our alternator burned out on a hot day. If we had not had an Adverc fitted, it probably wouldn't have burned out. But this did NOT mean that the Adverc had burned out the alternator; the reason it burned out, as far as I can tell, was because it always gets hot anyway (we have a cruiser stern) and I had not noticed that an accumulation of hairs from the dog had blocked the cooling slots on the back of the alternator. So really it was the dog's fault that I needed a new alternator - which I had to buy without a guarantee because I insisted on re-connecting the Adverc; but it's still working perfectly.

 

I hope this helps.

Allan

[chris w]

I'm not familiar with the Adverc unit but the Sterling Alternator Controller incorporates a temperature sensor for the alternator and for the batteries. The unit monitors the alternator temperature and switches off the control unit in event of high alternator temperature. The alternator controller automatically re-engages when the alternator cools down.

 

It does the same for the batteries too. Off the top of my head without checking, I believe the max battery temp allowed is 50degC and for the alternator 90degC.

 

Chris

[Keeping Up]

I'm not familiar with the Adverc unit but the Sterling Alternator Controller incorporates a temperature sensor for the alternator and for the batteries. The unit monitors the alternator temperature and switches off the control unit in event of high alternator temperature. The alternator controller automatically re-engages when the alternator cools down.

 

It does the same for the batteries too. Off the top of my head without checking, I believe the max battery temp allowed is 50degC and for the alternator 90degC.

 

Chris

The Adverc measures, and compensates for, battery temperature, but it doesn't measure the alternator temperature.

 

Allan

[Gibbo]

The problem with just using the alternator's regulator is that they are not a smart device. Although many WILL give out over 14v as compared to a typical car battery regulator at say 13.6v-13.8v max, they also contain a temperature sensing device which very quickly cuts the charging voltage down to normal levels.

 

I think you have misunderstood what the temperature sensor does in an internally regulated alternator.

 

It reduces the alternator output when the alternator gets dangerously hot in order to protect the alternator. It has nothing to do with the battery state of charge. This will still happen with the Sterling device fitted.

 

Fitting a *normal* external regulator bypasses this temperature sensor and is why *some* people have had problems with alternator failures when external controllers are fitted.

 

Otherwise they could run the risk of overcharging the batteries sans some other electronic control. Note that in the "SmartGauge" article quoted, the author doesn't address the issue of how a "high output" alternator regulator prevents battery overcharging.

 

It isn't required. Batteries limit their own charge current. This 10% or 15% charger size is an old wive's tale. As long as you don't go silly and fit a 1000 amp alternator to a 100Ah battery there isn't a problem. Even then it is doubtful whether the batteries will draw sufficient current to cause any damage to themselves.

 

The Sterling equipment (inter alia) will intelligently monitor your batteries and charge the batteries at the optimum voltage in order to get them 100% charged in a reasonable time. An alternator without some kind of regulator controller will never charge your domestic batteries up to full capacity. These controllers effectively bypass the actual alternator controller and take over the whole charging process.

 

Again this isn't strictly true. *any* voltage above 13.8 volts will fully recharge a lead acid battery but it's the time to do so that becomes a problem. As you state, increasing the charge voltage reduces the time required to fully recharge.

 

It is also a waste of money to simply buy a new alternator with a higher current rating because the current rating is not what goes into the battery (it is simply the maximum the alternator could deliver in theory). Alternator output current is controlled by the battery's needs

 

Hang on, above you said that high output alternators can overcharge batteries. Now you're saying that the batteries control the alternator current? Which is it?

 

and if charged at a low (normal) voltage they simply will not allow the alternator to deliver a high current. Also, alternator output varies with engine rpm.... you will be lucky to get more than half the quoted output at typical narrowboat revs even if the normal regulator charged at a high enough voltage.

 

 

Not if the alternator is pulley'd up correctly.

 

For the record, I have no connection with Sterling or any other similar manufacturer other than as a customer but as someone pointed out above "it does what it says on the tin"

 

For the record I do

 

Gibbo

[chris w]

Batteries limit their own charge current

The current into a battery is simply Ohms Law. At any state of charge the battery will have an internal resistance and the current will be determined by this resistance and the applied voltage. If you continue to apply a high voltage you will overcharge the batteries. That's why multistep chargers and alternator controllers drop down eventually to a float voltage.

 

Again this isn't strictly true. *any* voltage above 13.8 volts will fully recharge a lead acid battery but it's the time to do so that becomes a problem. As you state, increasing the charge voltage reduces the time required to fully recharge.

I know this, you know this, but I took it as read that we mean during a typical day's cruising time. Even a low cost basic 2A Halfords charger would eventually get a battery up to 100%.

 

Hang on, above you said that high output alternators can overcharge batteries. Now you're saying that the batteries control the alternator current? Which is it?

No I didn't, I said high alternator voltage output can overcharge batteries and you know that's what I meant. A high current output alternator is a total waste of money if you can't utilise that current.

 

Not if the alternator is pulley'd up correctly.

True but the vast majority aren't. The problem is that there exists a minimum alternator pulley diameter to ensure the alternator belt is correctly contacting the pulley. Often water pumps etc are run off the same belt, so one can't just start altering the main engine pulley. That coupled with the fact that NB engines generally run around the 800-1200rpm range most of the time means that the actual alternator output possible is way below its quoted output. And without a proper alternator controller you won't even gets what's possible.

 

For the record I do

Let me guess - you're the SmartGauge guy?

 

Trying to pick me up on every word is very sad - you should get out more Do you live alone?

[Gibbo]

The current into a battery is simply Ohms Law. At any state of charge the battery will have an internal resistance and the current will be determined by this resistance and the applied voltage. If you continue to apply a high voltage you will overcharge the batteries.

 

 

That depends what you mean by "a high voltage". Continuing to charge at say 14.4 volts will *not* overcharge the battery. Eventually, after a *very* long time, some water might be used.

 

 

That's why multistep chargers and alternator controllers drop down eventually to a float voltage.

 

And vehicle alternators do *not* drop down to a float voltage, yet these vehicles run for hours and hours at a time, day in day out, month after month, yet the batteries continue to live for years and years.

 

No I didn't, I said high alternator voltage output can overcharge batteries and you know that's what I meant.

 

You didn't. You said a "high output alternator" which anyone will construe as being high current not high voltage.

 

If you maintain that you did indeed mean high voltage (as in 14.4 or 14.6 or 14.8 volts), then the article *does * address why it does not overcharge batteries.

 

A high current output alternator is a total waste of money if you can't utilise that current.

 

Which you will be able to do if the voltage is correct. Which most of them now are.

 

 

Trying to pick me up on every word is very sad - you should get out more Do you live alone?

 

Actually what happened was you appeared here and made *several* technically and factually incorrect statments. You now seem to be a bit more careful what you write.

 

Gibbo

Edited November 13, 2006 by Gibbo

[chris w]

Gibbo

 

So are you the "SmartGauge" guy?

[Gibbo]

Gibbo

 

So are you the "SmartGauge" guy?

 

Yes, I assumed you knew I was.

 

You stated in an earlier post that there is some incorrect technical information on the website.

 

I am human and therefore not infallible but as far as I am aware there is nothing incorrect anywhere on the website. I would be most interested to hear from you what you consider to be technically incorrect.

 

Either on or off forum.

 

Gibbo

[chris w]

Gibbo

 

I noticed on your website that the automatic mains change-over relay circuit you installed on your own boat did not allow for the possibility of avoiding "mains doubling" when switching from shore mains to an active generator. The commercial units tend to incorporate a short delay between leaving shore mains and engaging the generator to avoid damaging the generator.

 

My comment about the technical differences was a lot to do with the alternator controllers which we have been discussing. I would love to get you and Charles Sterling into a room together. When I saw him last, I asked if he had seen your website, and he said he'd never heard of SmartGauge. It would be an interesting debate. I discussed at length some of the issues raised here. From what he told me, he vehemently disagrees with you and has solid technical reasons why.

 

I thought your article on the Peukert effect was excellent BTW.

Edited November 13, 2006 by chris w

[Gibbo]

Gibbo

 

I noticed on your website that the automatic mains change-over relay circuit you installed on your own boat did not allow for the possibility of avoiding "mains doubling" when switching from shore mains to an active generator.

 

The commercial units tend to incorporate a short delay between leaving shore mains and engaging the generator to avoid damaging the generator.

 

 

I don't use a generator, just shoreline and inverter, so it doesn't need a delay.

 

 

I would love to get you and Charles Sterling into a room together. When I saw him last, I asked if he had seen your website, and he said he's never heard of SmartGauge. It would be an interesting debate.

 

We have crossed paths in the past. As has Charles and everyone in the trade at some time.

 

Gibbo

[Gibbo]

 

My comment about the technical differences was a lot to do with the alternator controllers which we have been discussing. I would love to get you and Charles Sterling into a room together. When I saw him last, I asked if he had seen your website, and he said he'd never heard of SmartGauge. It would be an interesting debate. I discussed at length some of the issues raised here. From what he told me, he vehemently disagrees with you and has solid technical reasons why.

 

I thought your article on the Peukert effect was excellent BTW.

 

Of course he disagrees!

 

Here's how I see it.....

 

The biggest market for this type of equipment is actually the automotive market, not the marine market. The difference, in terms of sales volumes, is somehwere round 100:1 for me. It is proabably similar for many others.

 

Standard external alternator controllers that override the internal reg simply cannot be fitted to many modern vehicles. On some vehicles the engine management system protests and produces an error. Some are actually forced into limp home mode. 90% of modern vehicles simply cannot have one fitted.

 

What Sterling have done is develop a completely new way round this problem. Certain other alternator controller manufacturers are about to get left out in the cold. However there are many issues to be considered. And here is the simplest one that anyone can understand......

 

Power into the batteries is what we're interested in. Nothing else, just getting as much power as posible from the alternator into the batteries, as fast as possible. That's the whole point of these devices.

 

Er........... what's with the huge heatsinks and cooling fans? Shouldn't that power be going into the batteries instead of warming the world up?

 

Secondly, despite what some people will protest all day, the fact is that modern alternators on vehicles already charge at the higher voltages that these controllers produce. They already do it. It's no good saying they don't, all you have to do is get under the bonnet of 20 modern vehicles and you'll find that 18 of them already charge at the same voltage that a new expensive controller is going to produce.

 

So what's the point?

 

Gibbo

[John Orentas]

 

I would love to get you and Charles Sterling into a room together. When I saw him last, I asked if he had seen your website, and he said he'd never heard of SmartGauge. It would be an interesting debate.

 

I could not think of anything more boring, except perhaps Ian Duncan Smith chatting to Jeffery Archer.

 

Second thoughts no, they would be relatively scintillating and authoritative.

[chris w]

Gibbo

 

So are you saying that 3 stage or 4 stage charging has no merits? An alternator regulator will, at best, do an absorbtion charge only. What about equalisation/de-sulphating. Are these not benefits of an alternator controller over a straight regulator even if that regulator is putting out 14.2v?

 

Chris

[tomsk]

I could not think of anything more boring, except perhaps Ian Duncan Smith chatting to Jeffery Archer.

 

Second thoughts no, they would be relatively scintillating and authoritative.

 

Most astute and essentially correct point you've made all year John Have a beer

 

Gibbo

 

So are you saying that 3 stage or 4 stage charging has no merits? An alternator regulator will, at best, do an absorbtion charge only. What about equalisation/de-sulphating. Are these not benefits of an alternator controller over a straight regulator even if that regulator is putting out 14.2v?

 

Chris

 

Pass me the rusty blade, nurse...The screens if you will.....

Edited November 13, 2006 by tomsk

[Gibbo]

Gibbo

 

So are you saying that 3 stage or 4 stage charging has no merits? An alternator regulator will, at best, do an absorbtion charge only. What about equalisation/de-sulphating. Are these not benefits of an alternator controller over a straight regulator even if that regulator is putting out 14.2v?

 

Chris

 

No that's not quite what I'm saying. But neither is it that simple.

 

Firstly we need to define what 3 and 4 stage charging mean.

 

It used to be the case that 3 stage charging meant [stage 1] a bulk stage (i.e. current limited - whether by design or maximum available output) then [stage 2] acceptance/absorption (i.e. voltage limited) followed by float (i.e. voltage limited at a lower voltage). This still generally applies.

 

4 stage charging depends who you ask. Some manufacturers class an equalisation stage as being stage 4. Others refer to stage 4 as meaning nothing more than a new word for the float stage but in power supply mode. This is just playing with words to make the charger look bigger and better. It's no different to normal 3 stage (Victron's trick, this one).

 

Now a normal alternator is 2 stage. This you must agree on. Current limited (stage one - bulk) followed by voltage limited (stage 2 - acceptance).

 

The only difference an external controller adds is a float stage. But consider this....

 

Trucks and cars (how many? a few hundred million?) survive quite happily without this stage. Their batteries don't die even though they are charged continuously at 14.2 to 14.8 volts these days.

 

Most alternator controllers run in parallel with the internal regulator. In fact they use this as a boast.... "if it packs in the internal reg takes over". This means that if and when it tries to go into float, the internal reg holds it at the normal charge voltage anyway so the float stage doesn't even exist in this case!

 

Very few alternator controllers include an equalisation cycle. (yet again some manufacturers [most notably Mastervolt] confused the issue by re-using "equalistion" to mean what *everyone* else referred to as acceptance/absorption - I believe they have now reverted to acceptance/absorption).

 

So that's the only real difference. The float cycle. And it is no longer really necessary.

 

On AC powered chargers the game is completely different. Here the charger may be on for months at a time. Now I'm not suggesting for one minute that it is fine to charge batteries at 14.6 volts for 3 months. But it *is* fine to charge them at 14.6 volts for normal engine run times.

 

Now also consider this.... Where is the dividing line between a higher charge voltage and equalisation?

 

A battery regularly charged at 14.8 volts will hardly ever need to be desulphated. One charged at 14.0 volts will need it much more.

 

But what about if you charge the batteries at 15.5 volts? How often will desulphation be required then?

 

People jump up and say "you can't charge batteries at 15.5 volts!!!"....

 

Why not? I've been doing it for years with no ill effects. And get this, Yuasa/Lucas do the same, as do Trojan and a lot of the others.

 

It's not as simple as "3 stage charging is better" If you get the voltages right 2 stage is just as good. In fact many would argue that a very high power single stage voltagd limited charge is the ultimate for lead acid batteries.

 

Sometimes you have to shut the charger down after a full charge, other times you can leave it going for ever. It all depends what the charge voltages are.

 

But I can be certain of this. Charging at 14.8 volts (for wet cells) and keeping them at that voltage all day does them no harm whatsoever. Even higher voltages are fine, and they also get the batteries fully charged, very, very quickly.

 

There is no need for a few hundred quidsworth of alternator controller to do this.

 

There are some very minor subtle differences in some of the controllers that increase the charge rate by a few percent here and there or reduce water useage by a few percent. But they really are very subtle. Cycling the charge voltage is the main example.

 

Finally consider this: For around 100 years lead acid batteries have been charged using simple voltage limits. Usually around 15.5 to 16 volts. It worked quite happily for a *very* long time.

 

The only reason 3 stage charging came into being was to enable charging to take place while other equipment was still running from the batteries. That is the only reason it exists. This is why the charge voltages were 14.4 volts for so long. It's nothing to do with charging the batteries the best possible way. It's to prevent damage to the other loads.

 

Ask any charger manufacturer what voltage their chargers run at when the charger is designed to charge batteries when they are *not* being used (fork lifts, milk floats, trains etc) and you will find charge voltages *much* higher.

 

Gibbo

[chris w]

Gibbo

 

Interesting, but you quickly wandered away from my specific question. I agree that batteries can be charged at much higher voltages than most people think, so long as there is temperature and time control; it's one of the things that alternator controllers do well.

 

However, how do you get a constant current (bulk charge) out of an alternator regulator? It's a constant voltage device, so you'll only get the absorbtion charge. How do you get time control to avoid overcharging the batteries on a long run?

 

Chris

[Gibbo]

Gibbo

 

Interesting, but you quickly wandered away from my specific question. I agree that batteries can be charged at much higher voltages than most people think, so long as there is temperature and time control; it's one of the things that alternator controllers do well.

 

That's my whole point. All this clever control isn't needed. And alternator controllers do nothing of the sort. They merely increase the acceptance voltage and some of them wiggle it up and down a bit.

 

 

However, how do you get a constant current (bulk charge) out of an alternator regulator? It's a constant voltage device, so you'll only get the absorbtion charge.

 

 

So are you saying that if you put a 10 amp alternator onto a flat 500 amp hour battery the voltage will instantly rise to the regulation voltage? No of course you are not, the current will remain at 10 amps until it reaches the regulation voltage. That's what the bulk stage *is*.

 

Constant voltage *by definition* has unlimited current. Which clearly an alternator does not.

 

Or I'll turn it round another way, if you're saying that an internally regulated alternator cannot run in bulk mode (constant current), then how does an externally regulated alternator do this? What does it do that is different to control the current, remembering that with very few exceptions they don't even measure the curent.

 

 

How do you get time control to avoid overcharging the batteries on a long run?

 

 

Read the post again. You don't need it.

 

Gibbo

[smileypete]

I think both Gibbo and chris w are missing the point...

[Gibbo]

I think both Gibbo and chris w are missing the point...

 

The what *is* the point?

 

Gibbo

[blackrose]

Has anyone had any experience with the 'Adverc' battery management device?

 

Is the 'Adverc' unit similar in function to the 'Sterling Alternator to Battery Charger' - does anyone have any views?

 

I heard that the Adverc is the benchmark to which other manufacturers aspire (but that was from an Adverc owner). Yes it does smart 3 stage charging like the sterling.