Current meter

[Richard Bustens]

Hi Bic Col

I think the price diferance is a lot more than you think as a couple of gauges will be about £40-50 and a half decent management system will be £200+

But i do agree that there is little point in knowing what is going in or out at a given time, you need to know what is happening over the period between charges.

A glance at the meter and seeing 30A going in is not a lot of use if you then go to do somthing else and it changes because someone switches something on and draws 25A off for 30 mins.

With gauges you will not know this whereas with a management system you can see what has happened. and know exactly what is left in the batteries.

 

John

Going back to the Regulator

Are you saying with a marine alt there is no need for a seporate reg ?

[John Orentas]

Hi Colin.

 

Thanks for that, it may sound picky on my part but the system must inevitaly rely on some fairly crude calculations, the clue here is that as I suspected, you must tell the system what battery capacity you have installed. If it was in way smart it would tell you.

 

The only thing that bugs me slightly are the exagerated claims made by the makers or purveyors these things, they are in truth very limited in what

information they can display, they are entirely passive, they don't 'manage' anything.

 

I would certainly not describe myself as a Ludite, quite the opposite I have spent half a lifetime as a design and development engineer but as such there has always been a constant battle to separate the real from the pseudo.

 

John Squeers.

Edited December 20, 2004 by John Orentas

[Big COL]

John

 

The information gleaned from these meters is as you say basic, and the terminology reference meter is probably more accurate, as they are not automatic and do not manage the state of the batteries. This is done by the operator using the information to hand which is a lot more than you would get with a basic volt and amp meter. However they are a very useful tool to have, I have one installed on my boat and would not be without it, it allows me the choice of if and when the batteries need charging so as not to run low during the night. Although the information is basic, it is accurate enough for the use on a boat.

[Big COL]

Hi Richard

 

I purchased my first meter for my old boat for £150 when I said the price differential is minimal I was taking into account the time factor as well, I still calculate time even when fitting my own boat as any time spent doing something the long way round is wasted as you could have been doing something else with it.

Time management on a self fit is just as important as a commercial fit out unless its just a hobby an using the boat is of no real importance.

Edited December 20, 2004 by Big COL

[Big COL]

Hi Colin.

 

I would certainly not describe myself as a Luddite, quite the opposite I have spent half a lifetime as a design and development engineer but as such there has always been a constant battle to separate the real from the pseudo.

 

John Squeers.

 

 

Hi John

 

Neither do I but reading your previous reply brought a smile to my face as I got the feeling reading between the lines, that you tend to prefer systems that are tried and tested. I must admit I tend to be cautious with any new gadgets and usualy wait a couple of years for them to be tested by the public before forming an opinion. The Luddite label comes about from my refusal to own a credit card.

Edited December 20, 2004 by Big COL

[Alastair]

Price depends on capacity - I have a system that manages the output from my PV panel. It tells me the Ah put in, and what is drawn out. My fuse panel runs off this. Current is limited to 10A, so I only use it for lighting and water pump circuits. Still, it seems to give a fairly accurate voltage reading, and tells me exactly how many Ah are drawn out of the battery each day. Very very useful.

 

Cost? £85.

 

Had I known that it did all of the above, I would have bought a model with a bigger current capacity - I initially only purchased it to manage the PV panel.

[Richard Bustens]

PV Panel ???

Where is it fitted between the battery and the distribution board?

[John Orentas]

Colin.

 

You go out smashing looms up then ?

[John Orentas]

Richard.

 

I am saying I don't really know, I have never felt the need for one. It would be interesting if someone could do a back to back comparison in controlled conditions perhaps with a marine and an automotive alternator.

 

I think it was Martin who said that some of the newer alternators have been modifified to give a higher charge rate.

Edited December 20, 2004 by John Orentas

[Alastair]

to Richard.

 

PV Feeds controller. Controller sits between distribution panel and battery. If the PV panel is producing current, it will first get fed to anything pulling power from the distribution panel. If there is no power from PV, all power comes from the battery.

 

System seems to work, and it's fun watching the current draw when the water pump comes on - in strong sunlight, the PV produces enough that it directly powers the pump AND is simultaneously charges the battery.

[Alastair]

Should also add that it was a doddle to wire up. The company that sold the controller and PV also sold very good quality cabling. One cable from battery to controller, one from PV to controller. One from controller to distribution board.

http://www.unlimited-power.co.uk

[Richard Bustens]

Ar i see now a PV is a solar panel apollyvollywatsit lol.

John

Well if thats the case i will not get one to start with i will see how it behaves without one.

[Big COL]

Colin.

 

You go out smashing looms up then ?

 

 

Hi John

 

Run out of looms, moved on to Amp/Volt meters.

Edited December 20, 2004 by Big COL

[Martin]

Quotes from John:

1) Sixty amp reading meter not big enough! I have a 75 amp rated alternator and my ammeter reads +30 / 0 / -30 amps. I have had batteries new and old, flat and fully charged, very rarely has the meter gone off the scale and then only for a few seconds.

2) I tell people, don't ask the man in the shop or your boat builder MEASURE IT ! it's easy.

 

I am confused here!

One confusion lies in that it is so easy that you use a 30amp ammeter to measure a 75amp output.

Second confusion is why your alternator doesn't send your meter off the scale for longer and more often.

I have a 90amp alternator and yes, I measure output on a +/-60amp ammeter - I found it on a tractor at a scrapyard, it cost me £2.50 and it suffices to tell me if my alternator is charging or not.

My ammeter consistently goes off the scale and stays there - unless I cruise for more than five hours and get the batteries properly charged.

I can only assume that you use very little power and keep your batteries constantly fully charged.

 

Pressures at work mean that I haven't spent as much time digesting this thread as perhaps I ought before passing comment, but I have done a lot of research recently concerning battery management or alternator control.

I too was of the opinion that simple was better and that there was no way I would be forking out for one of these boxes.

While I have still to put my hand in my pocket and buy one, I will be doing so in the new year.

 

Not everything computerised or chipped in some way is inherently bad or mis-sold.

Trying to think of an analogy, the best I can come up with is my washing machine!

 

The housewife in days of old would have a tub and dolly.

Clothes would be washed using the correct amount of water - as determined by the housewife - and then rinsed until all the soap was removed.

Then came the "Automatic Washing Machine" - this is my parallel to the ordinary alternator.

You put the washing in the machine, set the "program" and switch it on.

The machine fills up with water - to a preset level.

It adds the detergent and then waggles the washing about for a preset time.

After that, it empties the water, adds clean water and rinses.

Then it spins and stops.

Everything was set by clockwork and there was no allowance for teenagers socks, heavy loads, half loads or anything else.

The standard alternator is much the same - it charges at a preset rate until it "senses" that the batteries are full.

In fact its charge drops as it meets the resistance all batteries have to being charged - the longer you charge, the higher the resistance and the less power gets shoved in. So you never get your batteries fully charged.

This is all set by the regulator in the alternator which is set by automotive standards to provide starting power for a fast revving car engine.

 

Technology has moved on.

In the case of the washing machine (my Bosch) it is more efficient and is able to mimic more closely the decisions made by the housewife with the tub.

It weighs the washing and decides how much water is required - it runs the wash cycle based on weight of load and whether you tell it there are teenage socks or net curtains on board and the material.

Based on this information it determines an approximate rinse time.

After this time it checks the washing - if it sees there is still froth on the water, it rinses again, and again if necessary.

After that and based on previously determined factors, it selects a spin speed.

It does a low rpm spin first to make sure the load is balanced and adjusts it by shuffling backwards and forwards if necessary before embarking upon the spin "proper".

Then it turns off - and beeps to tell you it is done.

 

The alternator controller works (in its latest guise) in the same way - measuring demand and managing supply to suit - so your batteries are charged as quickly and safely as possible based on alternator output, temperatures, battery state, battery type and so on.

 

I learnt a lot from talking to the guys at Adverc about there system and then interrogating Charles Sterling about his - putting questions to both parties as they arose.

 

Certainly the early Sterling controllers appear to leave something to be desired.

Adverc say that while it boosted the alternators charging, it did so according to a long timed cycle.

It shoved 15v to the batteries for a period of four hours allegedly.

(I find this doubtful but it was the only argument Adverc had against Sterling.)

If you stopped for lunch and then started your engine again - the old sterling would start its four hour cycle again, regardless of whether it was needed.

This led to the accusation that it boiled batteries.

I can't say whether it did or not.

Adverc say there system is better - it cycles for minutes rather than hours, floating and boosting, floating and boosting.

Both of these seem to me to be like early automatic washing machines.

 

Sterling's latest Digital Controller is "intelligent" or at least it relies as much on external stimuli as it does on programming.

Sensors tell it the voltage and amperage at both the alternator and the batteries.

It knows the alternator temperature and battery temperature so will not overheat either.

It maximises the alternators ability to charge according to this data in Real Time - not according to pre-programmed cycles - so you know that your batteries are getting what they need and not what the box thinks they ought to need.

You can also optimise the charging according to whether you have traction, gel, lead acid or other types of battery.

 

If a housewife had the time to handwash, she could judge precisely what was required, so the Bosch washer measures these factors electronically.

Likewise, if you had the time to optimise your battery charging by sitting with a multimeter and an electrical screwdriver to continually adjust the voltage regulator on the alternator, the latest generation of controllers do this for you.

 

I am of the opinion now that an uncontrolled alternator is a compromise - like early washing machines - but it is passive.

I will be buying a Sterling Pro Digital controller in January as I now believe this to provide a more efficient means of charging my batteries.

Only time will tell if I have got this right or whether I am being gullible!

If I am being gullible then it is because Sterling and Adverc are liars and exploiters of fools.

I hope the latter is not the case!

 

Hmmm.

Rest now - then beer!

[dor]

I think I agree with pretty much all of that Martin. One small point: My fairly early Stirling Alternator controller does indeed boost for a set time before measuring the need for a boost. However it is user-settable for 1, 2, 3 or 4 hours. I think the idea is you adjust it depending on what sort of use is made of your batteries and how big the bank is. I have mine set on one hour. If I think I want a bit more of a boost that the regulator thinks after an hour, I can stop the engine and restart it to reset the controller.

[Martin]

So Adverc were sort of right!

Thanks for getting through it - I didn't realise I had waffled on for so long until I hit the button!

[David Schweizer]

John O, you asked if anyone had experience of using a Marine Alternator with and without an Alternator Controller. This is a second hand experience, but of a very good friend with whom I often worked and boated. He had a 90a Marine Alternator fitted to his Beta Engine which failed to keep up with the demands of his Liveaboard boat, so he fitted an Eagle contoller, that managed to burn out the diodes on the Alternator (twice) especially when on the Thames where the thing reset itself with every engine re-start. So he dumped it and fitted a Sterling controller. he had no further problems with diodes and the contoller delivered enough power to keep the batteries fully charged, often delivering up to 50 amps for a couple of hours after a prolonged period with the engine not running.

 

On another point I appear to have what some people might call a Battery Management System on my boat, but built out of old Automotive and Electronocs components. I have two 60-0-60 ammeters (one in each charging circuit) and a shunted voltmeter (bought s/h for from a Radio spares shop) connected to both batteries through an ex MOD on/off/on switch (from an old aircraft control panel) This system enables me to monitor the charge to each battery and monitor the voltage of each battery bank independantly. Total cost - less than twenty pounds. and just to make sure I also have a hydrometer!

[John Orentas]

David.

 

The bottom line must always be the number of batteries being charged, delivering 50 amps for a prolonged period is ok as long as you are charging 4 or more fairly run down batteries.

 

I submitted a thread months ago advising on the need for increased ventilation and even forced cooling of alternators when they are working hard as you describe, no doubt everyone assumed that your friends diodes were popping as a result of excess current flowing through them, I would say it was more than likely that they suffered from the high temeratures that would inevitably exist around them. That's 600 watts + the ambient temp. of the engine compartment.

 

Your set up sounds like a the control panel on the Tardis, you can't have too much instrumentation, the difference of course is that you are in charge. I have never had much luck with hydrometers maybe I have just had some dud ones. What is a 'shunted voltmeter'.

[dor]

I understood that the percieved wisdom for prolonged charging was to charge batteries at 10% of their capacity. Some view that modern deep-cycle batteries can cope with 20%.

[Big COL]

Martin

 

 

Now you have decided that a controller is the right thing to use, have a look at Driftgate controllers I used one of these with my old boat and was impressed with the results that it gave, and the customer service was excellent. I would have used them on my new boat but as a sailaway it came with the beta controller.

[John Orentas]

Martin.

 

Good greif it's like replying to War and Peace.

 

I do not live on my boat, I have 2 x 110 Ah domestic batteries and one similar engine one all charged by a 75 amp alternator. The engine starts so easily, usually within one revolution so the engine battery is never less than fully charged so can be virtually discounted. When partially run down the two batteries charge at around 20A apart from a few seconds when the 30A ammeter goes of the scale. Much higher and there is a danger of over charging.

 

Charge rates should be governed by the quantity and size of the batteries rather than the maximum potential of the alternator, 10% of the capacity (see Dor on a parallel thread) so 20 amps seems about right. Just for fun, one day I loaded the system up to about 70 amps with the engine running, it ballanced the load easilly at tick-over. So as the charge and the useage rarely goes above 30 amps a +30 / -30 ammeter is more than adequate.

 

As for the other matters, I do not feel comforable as the anti-technology Ludite, I am just trying to give a bit of ballance.

 

Like you I may well buy a controller one day, but I would much prefer if someone could tell me how I could tap into my alternator, fit a wire or two and then have the provision a manual boost with a potentiometer or a switch. One of the boffins at the boat show one year started to tell me how to do it, is telephone rang and the moment was lost. Martin you seem to have contact with these people, any chance of finding out. ? In the interests of science of course.

Edited December 23, 2004 by John Orentas

[Martin]

I wonder about this charging rate too.

10% of my (now) 440AH is 44amps

(bear with me - it is my last day before Christmas!)

My 90amp alternator came off a Sierra 2.3l diesel - with a single battery.

If the battery was drained on a cold morning trying to start this Sierra, then the alternator would give its all (at least for a while) and be charging at about 100% of battery capacity.

The alternator controller manufacturers seem to have completely ignored this percentage of capacity idea - why?

 

I will be buying a Sterling/Prestolite package of controller and alternator together - the Prestolite alternator being rated at 110A.

I would need 10 batteries for this to balance out (at 110AH each) - or five if you go by the 20% version of the equation.

Yeah - OK - you're pretty close as I would actually have six.

 

Will certainly look at Driftgate but they don't seem to have much of a name - I for one have never heard of them!

 

M

[dor]

Ah Martin: the key word in my comment was "prolonged".

 

With a car, assuming normal starting, the amount of power used to start is about what, 1 amp-hour? I.e. 200 amps for 1/200 of an hour - i.e. about 20 seconds - quite generous really. So to all intents and purposes the battery is still virtually fully charged [/i]after doing all its work.

 

If you do really have to crank the engine for several minutes you will pretty soon knacker the battery: both from the high discharge rate, the depth of discharge and the high recharging rate as the battery is not designed to cope with that sort of activity.

 

In my studies, the figure of 10% was given for recharging quite heavily discharged batteries such as we have after a night watching tv, running a fridge etc (including making smoothies?). The more recent suggestion comes from the design of modern batteries being more able to cope with prolonged high charging rates (hmmm - maybe elecsol excluded!).

 

So Tolstoy, I don't think we are too far out!

[John Orentas]

Martin, Dor.

 

The alternator in Martins 2.3 Sierra is not there to just to charge the battery, it's main function is to balance the load of continuous driving on a winters night.

 

Headlights, stoplights, fog lights, heater fan, heated rear window, radio, oh yes and recharge the battery. That as we keep saying is the difference between cars and boats.

 

The alternator will output about 13.5 volts to drive all this lot the battery will look after itself, if there were 2 or 3 batteries the result would be the same, all the batts. would be charged at the same rate the regulator within the alternator would see to that, just working harder to cope with the extra load.

Edited December 23, 2004 by John Orentas

[timboharticus]

I do wonder whether these charge controllers are worthwhile.

 

If they cost say, £130 this equates to 2 off leasure batteries.

 

I have a wind generator and would be confident that all my batts would be fully charged on a regular basis.

 

So, is it better to buy a charge controller or just add an extra battery?