Battery type? Help please

[cereal tiller]

A car alternator is not primarily designed to charge a battery, that is it's secondary function.

A car alternator is designed to run all the electrics of a vehicle, that could be on at the same time. Could be 100 amps or more.

Heated front and rear screen, electric seat heaters, headlights, wipers etc. It is designed to do this over a wide engine rev range, however there are times when the alternator alone cannot meet this power load, sitting at traffic lights for example, so energy is taken from the battery to compensate the alternators short comings. When revs increase, there may be some excess charge available, then this is used to put some charge back into the battery.

Now with say a conventional narrow boat, or cruiser, the alternator doesn't have particularly high power requirements, a pump or two, electric fridge, some electronic instrumentation etc nowhere near the total amperage rating of the alternator. Not all this available alternator spare output is available to charge the battery, the battery itself limits the current, due to a fixed voltage generated by the car type alternator, so it does not efficiently charge the battery in the shortest possible time.

However, if the voltage of the alternator output can be increased to provide bulk charge then the battery can accept a larger current, and thus the battery can be charged more quickly. Provision has to be made to ensure minimum gassing occurs and the battery temperature can be monitored, a hot battery is not a healthy battery.

This is what you get when you get a marine charging system, such as those made by Sterling. As I say, a car alternator is not an efficient way to charge a battery, ok eventually it will, cruising 4- 6 hours a day (Broads hire craft suggest this figure),(depending on daily usage and battery state of charge) but if you don't do the cruising, you will burn many litres of diesel just sitting on the mooring putting a minimum inefficient charge into the batteries and risk glazing the bores of the cylinders.

A car type alternator is not that efficient at charging batteries, as I say, it was never designed to do that as it's first function.

Car alternators are used a lot... because they are cheap, easy to replace, and if you cruise several hours every day, do a superb job, but if you are a liveaboard, or don't cruise regularly, then you need a more efficient set up.

I will go with that,have a Greenie

 

I use standard A127 type Alternators,both assisted b a Sterling PDAR Controller,is does reduce the bulk phase and heads for 14.8 Volts quite briskly

 

CT

[MtB]

I think Mike would like the Sterling. It's very pretty

 

Actually, his is one of the situations where I think he'd really benefit from one, if Snib can't offer a better solution.

 

 

A Sterling wot??!

[WotEver]

A Sterling wot??!

Alternator controller - PDAR as above.

 

http://sterling-power.com/products/universal-advanced-digital-alternator-regulator-pro-reg-d-pdar

[cereal tiller]

 

 

A Sterling wot??!

Sterling PDAR Alternator Controller,as I stated in my last post

 

The Gibbites may wail a little,but they do work

 

 

CT

[WotEver]

Sterling PDAR Alternator Controller,as I stated in my last post

 

The Gibbites may wail a little,but they do work

I have no doubt that they work. I just wonder how often they're required.

 

In Mike's case I think the evidence is there that he requires one - his charging voltage is way too low.

[Naughty Cal]

 

I would agree. We have met a few boaters who have "boasted" about the huge lifetime of their batteries and I have concluded that this must be because they had massive over-capacity to start with, or have even slowly adjusted their lifestyle to cope with the falling capacity. We did moor next to a boat who appeared to do engine runs morning, mid-day and evening. I suspect now he runs his engine all day and lights a candle at night.

 

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

There is one boater on our moorings who often gloats about how his batteries have lasted him over ten years.

 

Well yes ours probably would if we only had one annual outing to Lincoln and back and the rest of the year we were plugged into the shore power.

 

As it happens I don't think we have done too badly to get five years out of our batteries. We don't exactly molly coddle them and they are subject to lots of being shaken and banged around at sea. They do however now need replacing when we go back in the water in March.

[jddevel]

My reference to "best to hire a boat and headaches" was as a poor soul fitting out a sailaway and as a layman trying to get to grips with all I should consider. Batteries or generator or inverter or all or a combination

etc. etc. The problems are added too as like all humans-well most- I`m trying to limit my mistakes and

therefore my regrets as to "not having thought of it before".

[dmr]

A modern 12V alternator should put out 14.4V. That is much the same voltage as a 3 stage charger and will charge the batteries just fine. What folk don't realise is that a full charge does indeed take many, many hours whether from shoreline, generator or alternator.

 

Remote marine alternator controllers were invented to part the gullible from their money. A correctly set up system shouldn't need one.

 

If your alternator only outputs 13.8V then upgrade it or change its regulator. If you have a diode splitter remove it. If you have remote sensing then it's very easy to up the voltage with one or more diodes. If you have too-small charging cables with a high voltage drop, replace them.

 

Tony

 

Take a read of this page: http://www.smartgauge.co.uk/alt_mod.html

 

 

 

Do you have any evidence that controllers are not required and only part the gullible from their money?

I have first hand experience that they make a huge improvement.

Some car alternators charge at 14.6, but even so at these low temperatures a controller will probably charge at 15v, that's a huge difference.

There is a lot of very good stuff on the smartgage web site but I don't think we should believe all of it. Remember that Gibbo did not make an alternator controller but did make SmartBank, and although this is a totally different device he did market it as a competitor to alternator controllers, he is therefore hardly likely to recommend alternator controllers.

 

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

[dmr]

I think Mike would like the Sterling. It's very pretty

 

Actually, his is one of the situations where I think he'd really benefit from one, if Snib can't offer a better solution.

 

I did think the the Sterling might be the slightly better device, despite its excess of flashing lights. However recent threads, especially from NickNorman, have proposed that a lower voltage actually charges faster, whilst my experience is that the higher voltage is essential to getting a fully charged battery. The Adverc cycles between two voltages and whilst I initially thought this was a bit gimmicky I am now wondering if it actually works very well.

The Adverc would look very at home next to a Kelvin.

 

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

[MtB]

 

I did think the the Sterling might be the slightly better device, despite its excess of flashing lights. However recent threads, especially from NickNorman, have proposed that a lower voltage actually charges faster, whilst my experience is that the higher voltage is essential to getting a fully charged battery. The Adverc cycles between two voltages and whilst I initially thought this was a bit gimmicky I am now wondering if it actually works very well.

The Adverc would look very at home next to a Kelvin.

 

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

 

You mentioned the other day persuading your Adverc to equalise whilst cruising. I tried calling Adverc to ask them about this but their phone message always says no-one is available. So I emailed them - no response. What did you do? I think you said it was a modification of your own...

[dmr]

 

You mentioned the other day persuading your Adverc to equalise whilst cruising. I tried calling Adverc to ask them about this but their phone message always says no-one is available. So I emailed them - no response. What did you do? I think you said it was a modification of your own...

 

Adverc are usually very helpful on the phone but they are a very small company so don't always answer the phone. The main boss man (Brian) who I think designed the controller has retired, or at least semi-retired, so the level of expertise is not quite what it was. I do suspect that Adverc are now just making the old stuff rather than coming up with new ideas, but the old stuff is still good.

 

There is a voltage adjustment inside the Adverc and my mod is simply to move this to be accessible from outside the box. Adverc know I have done this (and provided information) but I suspect they would not recommend this on a unit still in warantee.

 

It works well for equalisation, the only drawback is that the Adverc cycles between two voltages which can make equalisation rather slow, especially as the Adverc goes into a long low voltage period after a few cycles. I have a half baked plan to find a way to switch this cycling off but this will involve reverse engineering the circuit board. I have a spare Adverc here if you know anybody who has the patience to trace out the circuit.

 

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

Edited January 6, 2017 by dmr

[MtB]

 

Adverc are usually very helpful on the phone but they are a very small company so don't always answer the phone. The main boss man (Brian) who I think designed the controller has retired, or at least semi-retired, so the level of expertise is not quite what it was. I do suspect that Adverc are now just making the old stuff rather than coming up with new ideas, but the old stuff is still good.

 

There is a voltage adjustment inside the Adverc and my mod is simply to move this to be accessible from outside the box. Adverc know I have done this (and provided information) but I suspect they would not recommend this on a unit still in warantee.

 

It works well for equalisation, the only drawback is that the Adverc cycles between two voltages which can make equalisation rather slow, especially as the Adverc goes into a long low voltage period after a few cycles. I have a half baked plan to find a way to switch this cycling off but this will involve reverse engineering the circuit board. I have a spare Adverc here if you know anybody who has the patience to trace out the circuit.

 

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

 

 

Email me a photo of each side of the board and I'll have a bash!!

 

Yes I got the impression it was a tiny outfit from their website. Could only find some salesy blurb about their alternator controller though, not any proper technical description of what it does. Maybe I didn't look properly,

 

Anyway I'm off to Kingston on Thames now to fix an electric boiler for an electrician, who surprisingly can't do it himself despite a fair bit of coaching on the phone. He's given up and just wants the damned thing working, NOW!

[dmr]

 

 

Email me a photo of each side of the board and I'll have a bash!!

 

Yes I got the impression it was a tiny outfit from their website. Could only find some salesy blurb about their alternator controller though, not any proper technical description of what it does. Maybe I didn't look properly,

 

Anyway I'm off to Kingston on Thames now to fix an electric boiler for an electrician, who surprisingly can't do it himself despite a fair bit of coaching on the phone. He's given up and just wants the damned thing working, NOW!

 

Go to the products/Adverc Systems section and download the installation instructions. There is also some stuff in the technical library section.

Adverc have a new website and sadly it suffers a bit from the Axiom syndrome of wildly exaggerated claims, I wonder if this is because the main technical man has retired?.

 

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

[WotEver]

... recent threads, especially from NickNorman, have proposed that a lower voltage actually charges faster, whilst my experience is that the higher voltage is essential to getting a fully charged battery.

 

Yes, a higher voltage will create increased gassing, the actual voltage at which this becomes sub-optimal being determined in part by temperature. The extra bubbles on the plates work as little insulators which will decrease the amount of charge going into the battery. As the battery SoC approaches 100% so the gassing voltage reduces, with a fully charged battery starting to gas at about 13.4V.

 

So in brief, increasing the charge voltage will start to increase the rate of charge until it reaches an equilibrium state with the gassing. Further increases in voltage will then only increase gassing and decrease the charge rate. The corollary to that is that as the charge increases towards 100% the charge voltage should, ideally, drop slowly if you want to get the best charge in the shortest possible time. Plenty of charger manufacturers have looked into methods of achieving this, but they've all given it up as too expensive and complex.

 

If you can be bothered to wade through a Gibbo & Smiley Pete vs Chris W spat, the phenomenon is discussed in some detail here: http://www.canalworld.net/forums/index.php?showtopic=22313&page=6#entry371463

 

Tony

[WotEver]

 

Do you have any evidence that controllers are not required and only part the gullible from their money?

 

Dave, I posted that in response to "A standard car alternator cannot fully charge a battery without an external controller" which is patent nonsense.

 

Can an external controller increase the charging efficiency of an alternator? Of course, in some circumstances. Are they 'required'? Yes, in some circumstances, but I'd wager far fewer times than they're actually fitted.

 

Caravans are commonly fitted with a 13.6V PSU which doubles as a battery charger. For those vans which spend 365 days of the year on hook up either at home or on site that PSU keeps the battery fully charged. Yet there are hundreds of caravan owners who leave their vans on their drives with a Ctek battery charger connected because "that's the only way to have the battery fully charged". They've heard it so many times that they believe it must be fact.

 

Just because something can improve a situation it doesn't mean that the other method doesn't work, simply that the other method can be improved if required.

 

Tony

[Richard10002]

 

 

 

So in brief, increasing the charge voltage will start to increase the rate of charge until it reaches an equilibrium state with the gassing. Further increases in voltage will then only increase gassing and decrease the charge rate. The corollary to that is that as the charge increases towards 100% the charge voltage should, ideally, drop slowly if you want to get the best charge in the shortest possible time. Plenty of charger manufacturers have looked into methods of achieving this, but they've all given it up as too expensive and complex.

 

I've got a charger which gives the option of a variety of absorbtion voltages, 15.1V, 14.9V, 14.4V, 14.1V, as well as 15.5V for equalising. I generally set it at 15.1V for charging, and reset it every hour if it reverts to float.

 

Presumably, assuming your theory is correct, (and I have no doubt that it is), I could operate the system manually, such that I could charge at 15.1V from say, 80A down to say, 20A, then reduce the voltage to 14.4V down to say, 10A, then 14.1V until it's as low as it wants to go.

 

I have 4 x Trojan T105 at present. What would you suggest as a sensible regime to maximise the charge/gassing efficiency, or how would one go about designing one, (given the voltages available to me)?

[WotEver]

 

I've got a charger which gives the option of a variety of absorbtion voltages, 15.1V, 14.9V, 14.4V, 14.1V, as well as 15.5V for equalising. I generally set it at 15.1V for charging, and reset it every hour if it reverts to float.

 

Presumably, assuming your theory is correct, (and I have no doubt that it is), I could operate the system manually, such that I could charge at 15.1V from say, 80A down to say, 20A, then reduce the voltage to 14.4V down to say, 10A, then 14.1V until it's as low as it wants to go.

 

I have 4 x Trojan T105 at present. What would you suggest as a sensible regime to maximise the charge/gassing efficiency, or how would one go about designing one, (given the voltages available to me)?

 

Hi Richard,

 

Yes, you could do as you suggest but the only way I could think of trying it without some form of manometer reading of the gassing (if that would even work) would be by trial and error. Try reducing the voltages at various stages and see how long it takes to get to 100% SoC. Then try again, reducing the voltages at a different (later or earlier) part of the cycle and see if the charge time has decreased or increased. The fact that it's so hard to determine the 'optimal' voltage is why no charger manufacturer has incorporated such an algorithm into their products.

 

Of course, the other advantage of lowering the voltage is reduced plate corrosion.

 

Tony

[dmr]

 

Yes, a higher voltage will create increased gassing, the actual voltage at which this becomes sub-optimal being determined in part by temperature. The extra bubbles on the plates work as little insulators which will decrease the amount of charge going into the battery. As the battery SoC approaches 100% so the gassing voltage reduces, with a fully charged battery starting to gas at about 13.4V.

 

So in brief, increasing the charge voltage will start to increase the rate of charge until it reaches an equilibrium state with the gassing. Further increases in voltage will then only increase gassing and decrease the charge rate. The corollary to that is that as the charge increases towards 100% the charge voltage should, ideally, drop slowly if you want to get the best charge in the shortest possible time. Plenty of charger manufacturers have looked into methods of achieving this, but they've all given it up as too expensive and complex.

 

If you can be bothered to wade through a Gibbo & Smiley Pete vs Chris W spat, the phenomenon is discussed in some detail here: http://www.canalworld.net/forums/index.php?showtopic=22313&page=6#entry371463

 

Tony

 

Ta, I will read thru that thread a bit later. I did use to enjoy some of the Gibbo spats.

 

The Trojan (and US?) charging spec actually suggests INCREASING the charging voltage towards the end of charging, right up to 16volts I think. This may well be to do extra gassing to stir up the electrolyte, or to do a mini equalise.

 

I don't dispute your theory that a lower voltage charges faster due to absence of bubbles (cus NickNorman said so too) but how do I resolve this with my repeated observations that my batteries charge better at 14,.8 rather than 14.4 or 14.6? Also most Trojan owners appear to charge successfully at 14.8. Trojan themselves even suggested 15volts. Maybe it is the final high voltage "tickle" that does the business and the higher voltage earlier on is counter productive but I am not yet convinced of this.

When we run the engine we don't always know for how long it will be for so can't really do a final tickle (even if we had a charger that could do that) so again maybe the Adverc cycle is the best compromise. I am effectively cycling my charging between 14.4 and 14.8 volts.

 

Another thought, not all cells are equal so maybe the "higher than gassing" charge voltage actually prevents some of cells from getting a less charge than they might like at the expense of more gassing in the others, again a sort of mini equalise on every charge, and this outweighs any loss from charging at the higher voltage?.

 

My Iskra has a very soft regulator so the Adverc substantially increases the current during the bulk phase as well as raising the absorption voltage.

 

I will be retiring the two oldest two Trojans soon and would love to do some charging experiments but I'm a full time cc'ing liveaboard and don't really think battery experiments in our limited living space is a good idea.

 

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

[nicknorman]

Yes Nick suggested they are probably getting to less than 90% despite the SG reading given the low temp in the back cabin where they are installed. A whole extra charging Volt is needed for batteries at approaching 0^oC

 

This seems a major failing of the SG to me. No temperature compensation.

 

I need to set up a custom profile for the Pro Charge Ultra, but the SG simply cannot be trusted to be anything approaching accurate when it is reporting over about 90% it appears.

How do I persuade the alternator to charge at a higher voltage?

I don't think I mentioned 90% did I? I think you are getting fairly close to 100% but your batteries, like Trojans, want a high finishing voltage after each charge. A mini-equalise if you like. Exactly why, I dont know, but in this case I'm inclined to think that the manufacturer knows best.

[nicknorman]

I've got a charger which gives the option of a variety of absorbtion voltages, 15.1V, 14.9V, 14.4V, 14.1V, as well as 15.5V for equalising. I generally set it at 15.1V for charging, and reset it every hour if it reverts to float.

 

Presumably, assuming your theory is correct, (and I have no doubt that it is), I could operate the system manually, such that I could charge at 15.1V from say, 80A down to say, 20A, then reduce the voltage to 14.4V down to say, 10A, then 14.1V until it's as low as it wants to go.

 

I have 4 x Trojan T105 at present. What would you suggest as a sensible regime to maximise the charge/gassing efficiency, or how would one go about designing one, (given the voltages available to me)?

This diagram is from the Trojan user guide. Notice the SoC axis is not linear.

 

 

So they say initial charge up to 90% at 14.1v (at 25C) then once the tail current has fallen to 1-3% (ie the common man's fully charged, but as the chart shows actually around 95% SoC) raise the voltage to 14.7v to 16.2v. Again, voltages at 25C so add 1v at 5C.

 

Of course this regime may be mostly about maximising battery life, rather than minimising charging time.

[ditchcrawler]

 

I did think the the Sterling might be the slightly better device, despite its excess of flashing lights. However recent threads, especially from NickNorman, have proposed that a lower voltage actually charges faster, whilst my experience is that the higher voltage is essential to getting a fully charged battery. The Adverc cycles between two voltages and whilst I initially thought this was a bit gimmicky I am now wondering if it actually works very well.

The Adverc would look very at home next to a Kelvin.

 

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

I like mine, I should really rill a hole in it and twiddle the voltage pot

[ditchcrawler]

 

 

Email me a photo of each side of the board and I'll have a bash!!

 

Yes I got the impression it was a tiny outfit from their website. Could only find some salesy blurb about their alternator controller though, not any proper technical description of what it does. Maybe I didn't look properly,

 

Anyway I'm off to Kingston on Thames now to fix an electric boiler for an electrician, who surprisingly can't do it himself despite a fair bit of coaching on the phone. He's given up and just wants the damned thing working, NOW!

When I fitted mine I had a problem and rang them, "he" was about to go on holiday but we chatted through a few ideas that we both thought would work.

[WotEver]

I don't think I mentioned 90% did I? I think you are getting fairly close to 100% but your batteries, like Trojans, want a high finishing voltage after each charge. A mini-equalise if you like. Exactly why, I dont know, but in this case I'm inclined to think that the manufacturer knows best.

 

 

This diagram is from the Trojan user guide. Notice the SoC axis is not linear.

 

IMG_0537.PNG

 

So they say initial charge up to 90% at 14.1v (at 25C) then once the tail current has fallen to 1-3% (ie the common man's fully charged, but as the chart shows actually around 95% SoC) raise the voltage to 14.7v to 16.2v. Again, voltages at 25C so add 1v at 5C.

 

Of course this regime may be mostly about maximising battery life, rather than minimising charging time.

 

I suspect, as you do, that Trojan want to see every last bit of sulphate removed, which the high tail voltage will hopefully achieve. Again, as you say, the gassing vs charge-time is only relevant wrt the time it takes to get the charge to 100%, not something that Trojan will care too much about. They say to finish the last percent or two at a high voltage, so I certainly wouldn't argue with that.

 

It's interesing that Trojan recommend the bulk of the charge to be carried out at what could be considered a 'normal alternator' voltage.

 

Tony

[RD1]

About 20 years ago I was asked to design the electronics to test remanufactured car alternators, the ones you find as exchange units in Halfords and the like.

I did a lot of research at the time, some regulators were remote, usually the Japanese units, most lucas type were on board, some had the tachometer output.

 

The output was tested into a dummy load and voltage readings and revs were taken and the output parameters checked against known data, and there were many alternator types even then. Non had a variable regulator at the time, and the average test voltage output was 14.4 volts +/- a tolerance as per the data sheet.

 

Batteries should have the charge voltage changed to suit the ambient temperature of the surroundings, but also of the battery it'self but 20 years ago, no facilities were available, so it was a case of..... that'll do, and most of the time it was fine in the UK environment, and possibly world wide, maybe Volvos and Saab had something extra for their environment not personally aware of anything though.

 

These days a modern alternator tester would be linked to a computer and most tests automatic, but Mr Alternator repair man, can probably repair your alternator for a fraction of the price of an exchange unit, usually while you wait and most of the time, the fault is usually the diode bank, symptoms are... a discharge of the battery when nothing is on, proven by disconnecting the alternator plug.

The other fault is worn pick up brushes, no output, but after very high mileage, or the regulator can fail. Not forgetting if the ignition warning lamp has failed, it won't give the start up current to the field windings, so no output. (some do self excite... oohh missus).

Mr Alternator repair man probably has a big electric motor, an ammeter and a voltmeter and a battery, throw the alternator onto the test rig before repair and after repair, if there is an improvement after replacing something.... job done. 99.9% of the time the repair is successful.

 

So I hope this post can help a few of you, to diagnose an alternator fault and not overspend on an exchange or a call out fee for something fairly simple.

 

When we comissioned the alternator test rig, the client asked for a reconditioned starter motor tester... boy this was a challenge, some hefty currents there, but hey we did that too, I did the electronics, a colleague did the mechanics.

 

I wouldn't know where to start on the latest alternators, our Yeti has stop start technology, with regenerative braking that puts power back to the battery when you slow down. I monitored the voltage once on a one hour car journey and the voltage on the accessory socket in the car varied between 12.5 volts to over 14.5 volts ... I initially thought duff alternator, but the battery voltage has to be low to accept a regenerative output from the alternator when you slow down. Too much technology to go wrong in my opinion... The battery is a heavy duty AGM battery, that has to be coded to the car if you change it... hmm 1 step forward, three steps back...

 

I prefer old technology, a 9v battery a bulb and a length of wire, gaffer tape and WD40 If it moves and it shouldn't... gaffer tape, if it doesn't move and it should... WD40

If a small hammer doesn't work... get a bigger hammer. I think this methology still applies to most of the older boats, and can be fixed at the riverside with a basic tool kit, once they start adding dpf filters and emission controls to boat engines with all the sensors that invariably go wrong, and the fault codes, and laptops to diagnose the fault, then I think boating will be out of the budget of a lot of boat owners. I think the time will come, they have made a start and stopped the manufacture and sales of new two stroke outboards because of excessive emissions. What will be next? I think we have a few years yet, and what is ok today, will still be ok when any new legislation does eventually come in.

 

Best regards,

Richard

[WotEver]

I prefer old technology, a 9v battery a bulb and a length of wire, gaffer tape and WD40 If it moves and it shouldn't... gaffer tape, if it doesn't move and it should... WD40

If a small hammer doesn't work... get a bigger hammer.

 

My kind of engineering

 

Also, the reason I'm not a fan of alternator controllers - one more black box to go wrong.

 

Tony