Dazedkipper
Well-Known Member
Must have gone to the same school of customer care as O'leary of Ryanair, lol
Sterling charger failed after less than 3years and they want £245 to replace
- Thread starter ianj99
- Start date
Must have gone to the same school of customer care as O'leary of Ryanair, lol
Westerly Jetstream
Active Member
May I be allowed to throw something else into the excellent discussion? Can I presume that the battery bank of whatever size doesn't care wether its getting it's charge from a sophisticated multi stage charger or an advanced multi stage controlled alternator? If so is there any reason why the sizing of the Alternator for a 440 Ah battery bank should be any different to a mains charger? I was ridiculed on this forum in the past by suggesting that a bigger alternator was required for a larger bank, also ridiculed for suggesting that an alternator could NOT produce its rated output for more than a few minutes. After following this thread with keen interest it is obvious to me there are some excellent engineers contributing.
I have spent the most of this morning trawling the web on alternator manufacturers sites and without exception they all state that the max efficiency of their products is approx 60% for continuous running if the alternator is not to suffer damage, it therefore seems to me that what I've always believed and fitted to customers boats i.e. an alternator sized at 25% of battery bank is min requirement. Could this please be included in discussions as i'm sure the thread followers are interested in a complete charging solution not just a marina one, so many of us being on swinging moorings?
I have spent the most of this morning trawling the web on alternator manufacturers sites and without exception they all state that the max efficiency of their products is approx 60% for continuous running if the alternator is not to suffer damage, it therefore seems to me that what I've always believed and fitted to customers boats i.e. an alternator sized at 25% of battery bank is min requirement. Could this please be included in discussions as i'm sure the thread followers are interested in a complete charging solution not just a marina one, so many of us being on swinging moorings?
Tranona
Well-Known Member
Sorry, I read it that a spike in the mains had blown the transistor.
Tranona
Well-Known Member
Rather like the other bases for a claim this is less helpful than it seems. It is subjective and dependent on some form of reference point. Unlikely that there is any freely available data on the life of such items as a battery charger, particularly one that sells in small volumes and is subject to a wide range of different patterns of usage.
sailinglegend420
Well-Known Member
Correct - and for maximum charging efficiency yes they both should be 25%, maybe 30% of battery capacity to be able to deliver 20% of C into the batteries.
Automotive alternators certainly can't give their rated output for very long, which is why for serious long-term, not weekend cruisers, then a very expensive marine "hot rated" alternator is needed, like the Balmar range. They have more cooling fans and higher rated diodes and will give an output a lot closer to their rated output for a lot longer. To protect the alternator they should also have a regulator with an alternator temperature sensor to cut the charging current down to protect the alternator. Particularly important with AGM or Lithium Ion batteries.
A complete charging solution covering every kind of boat installation and usage is a book that hasn't been written yet. Here we can all only give ideas which are generalizations - which unfortunately often lead to more confusion and misunderstanding.
Plevier
Well-Known Member
Very nice, no disagreement with any of that.
Would only add that 14.4V is quite conservative and likely to be tolerated even by a lead-calcium "maintenance free" battery although they usually set a limit of 14.2V for warranty.
Using up to 15V will shorten the absorption phase but off the cuff I can't put a figure on how much. However as this phase progresses gassing will increase to a significantly higher level than at 14.4V, consequently it will increase water loss so not a good idea unless you can top the battery up. Transition to float voltage should be by current level rather than time, and will need to be at a higher current level than it would at 14.4V, corresponding to about the same state of charge.
You still have the killer of very slow recharge of the last 5-10% at 13.8V. As you near 100% the current will drop to typically 0.2-0.5A/100Ah and the charge efficiency will tend to 0%.
Overall therefore the time saving is not huge, but it will get you to the 90% region quicker.
At less than 13.8V the time for the last few % will increase enormously.
Mistroma
Well-Known Member
I think I remember the thread you are talking about and it seemed to me that the problems was a mixture of people talking about different things and also the odd incorrect post. I got the distinct impression that some people were talking at cross purposes and were correct within their own limited boundaries.
I mentioned in post #69 that I only needed a 23A charger for my 450A T105 bank when using Charles Reed's calcs.
My own calcs. showed 60A was more reasonable based on Trojans own information and Victron's site.
I asked for links to support Charles Reed's point of view but had no response. However, I think Charles later said that a larger charger was a benefit when charging from a generator (as mentioned in #69).
The odd thing was that Charles and myself both quoted Victron's site to support completely different charger sizes. However, I quoted the document and page number. I think that Sailinglegend420 also used the same information from Trojan ("10%-13% of capacity") and his calcs. agreed with mine.
Perhaps Charles actually meant that a 23A charger would be kindest to my 450A bank if I could run that charger for long periods. I wouldn't disagree with that but need a system capable of meeting my lifestyle. I could optimise battery life but doubt I'd be able to remain at anchor away from shorepower without significant changes to boat systems. My current setup is, as you'd expect, a compromise and not ideal.
I know we are getting a lot of thread drift. However, I've seen nothing to convince me that uprating from 40A charger to 60A charger (not Sterling) would be a bad idea "for my particular system and the way in which it is used". I think lack of context often causes a lot of apparent disagreement.
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charles_reed
Well-Known Member
I once had a 35 amp alternator on the 2GM - that regularly burnt its diode bridge and, adding insult to injury, used to slip and distribute burnt-belt dust all round the engine compartment. Going to a 90amp Lucas marine alternator cured the belt-dust and improved time between diode bridge replacement. This may have had more to do with having a solid machined pulley instead of the diabolical pressing with which all Hitachis appear to be afflicted.
By far the best alternator was the 110 amp Magnetti Marelli - but that was OEM on a slow revving Fiat diesel so had a much steeper output curve than any auto alternator, producing 80% of total output @ 2500 rpm @ crankshaft. That outlived the 2GM and did the first 1000 hrs on the 3YM, before time and obsolescence meant it had to be junked.
The OEM Hitachi 60amp on the 3YM literally melted and has since been replaced by a 90 amp unit of unknown provenance designed as an Hitachi replacement. This latter has 20% larger armatures and rotor and an external fan. It cost €149.00 in Agrinio.
As far as I know the only difference between auto alternators and marine alternators are that the latter are double-insulated and have stainless bearings rather than ordinary steel ones.
Balmar, who were one of my clients in the UK, are aftermarket manufacturers with no great claims to superiority and are very competitively priced but no doubt retailers seeing the approach of starry-eyed yotties rejoice and double the prices they charge.
Now my battery bank has never exceeded 330 AH, (I just can't fit in any more batteries), but I always have used an external smart regulator - 60 amp output is plainly inadequate and 110amps worked just fine for 10 years.
There is a limit, dictated by space and by the amount of drive that the alternator belt can transmit, and a hidden problem - that most marine engine harnesses have fairly small cross-section alternator - battery lead. Mine started to overheat when I went from the 35 amp to the 90 amp alternator - replaced with a 50mm2 cable.
Most petrol engine auto alternators are totally unsuitable for marine use - they peak at about 9000 rpm, are designed to produce their full output for 20' tops. What yotties need are alternators as fitted to cast-iron head diesel engines ( ie Transit or early Ducato).
As to whether one should discuss chargers and alternators in the same thread - well why draw the line there, what about PV panels and wind generators, they're all part of the same holistic approach. For me mains chargers are way down my list of important sources of electricity - apart from the beginning and end of the season I'm nowhere near shorepower ac.
Apart from the 90amp alternator with Adverc charger, I've 328 watts of PV panel feeding @ 24 v through a 500 watt MPPT controller. Wind generation is, @ 40N, an economic non-starter, 3 years ago the capital cost per AH was £18 for PV panels and £33 for wind generation and the gulf has widened since then with PV panels becoming even cheaper.
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halcyon
Well-Known Member
Using 10% capacity for rating chargers is a old one, and good in that it allow a good deep charge. Back in the 1980's when I was designing and building chargers, we used 10% capacity, and 14.3 volt charge. We got round small charger size by using the VSR charge programme, charging the service battery, then switching in engine batteries, thus reducing a total 440 amp hour to 220 + 110 + 110. Thus making a 25 amp charger work overnight, when the power supply function was not required. The 14.3 volt was a safe level we could achieve to provide reliable switching to float charge, an old battery may fail to reach more than 14.6 volt, so not trip level for the electronics. I found that once we reached a controlled 14.3 volt, charge current dropped of rapidly to mlli amps, so though taking longer in bulk mode, it saved a lot of high voltage running.
If you charge at a high rate, you convert the outer layer of the active material rapidly, giving the rapid high voltage that you see, this generates a lot of gassing and bubbles on the plates that further increases conversion problems, resulting in the long high voltage running you see to achieve full charge. As the battery is not a bucket you pour amps into, but a chemical conversion, the optimum charge is set by the chemical conversion rate, not how many amps you throw at it.
What I always say is look at battery manufactures web site, or ask them, you need to meet that requirement not a general rule of thumb.
Brian
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charles_reed
Well-Known Member
Sterling quotes 13.4 - 13.8, Dolphin 13.2 - 13.8, BZ 14.2 - 14.4, CTek 13.5 - 13.9, Shark 13.7.
If you look at the odd one out it's US - nothing separates us like our common language.
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ianj99
Well-Known Member
The conclusion you should find is that the only way to get closer to the illusive 100% using an alternator is to adopt Mr Sterlings principle of high voltage very high current.
If you distill the posts in the thread for mains chargers, you will realise that sticking to 25% of battery ah as a max charing current means that many hours of charging are needed even to get to 90% and not many of use would want to run the engine for hours as a rule...
As no one else will stick their neck out with a rough rule of thumb guide for a mains chargers I will: (assuming battery is at 40%)
1) Choose a charger of 20-25% of battery capacity
2) Allow 3-5hours to get to 80%, same again to get to 90%, same again to get to 95% (say 10hours) and another 10 hours to get to 100% (depending on charger and battery type).
3)This applies regardless of battery size.
In other words, overnight to get to 95%, a full day for 100% assuming no load.
When it comes to alternators you can immediately see that adhering to the 20-25% rule means engine driven charging would require as many hours - not practicable even for a mobo.
Sterlings principle is therefore necessary and one used by canal boat owners to minimise engine hours but it does require batteries that can stand being charged at way more 25% of capacity. My Optima Blue top is one such type that can accept unlimited changing current but for a limited time. (5hours I think).
Solare and wind sources are obviously great at keeping batteries top up during the week, but not much help when on board.
Mistroma
Well-Known Member
If you check, you will see that I was actually quoting from the battery manufacturers own web-site (+downloadable documents & tech. support).
My point was that:
"I mentioned in post #69 that I only needed a 23A charger for my 450A T105 bank when using Charles Reed's calcs.
My own calcs. showed 60A was more reasonable based on Trojans own information and Victron's site."
I've only been trying in vain to find out where Victron have information indicating that I should only need 23A. Charles Reed said 60A charger for 1000-1200Ah battery bank with conventional flooded batteries.
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charles_reed
Well-Known Member
Mistroma - I have never said that you needed 23 amp output for your charger with 450ah of battery - I did infer that a 60 amp charger would be adequate for as much as 1200 ah capacity.
One should avoid putting words in person's mouth. ;-)
One should avoid putting words in person's mouth. ;-)
Mistroma
Well-Known Member
Not certain how I'm putting words in your mouth, but apologies if I seem to be doing that. Just making a pro-rata comparison with my 450Ah battery bank which is less than half the 1000Ah and 1200Ah examples you used. Perhaps I should have stuck with your 1000Ah and 1200Ah examples.
Please ignore that complication for the present and I'll just stick to what you did say.
This made me think that you considered a 60A charger to be the size you'd expect to use with a 1200Ah bank. Not certain what else you meant to imply.
I thought that I'd find supporting evidence on this site but couldn't find it. Hence repeated requests for a link so that I could examine the material. It seemed to contradict other information I'd seen on that site (Page 24 Energy Unlimited book, http://www.victronenergy.com/support-and-downloads/white-papers/). I admit that they suggest limiting to 20% or better 10% of capacity. Unfortunately, I need to minimise time charging from 50% - 80% levels and don't have the luxury of charging at a much lower current in that range. Perhaps that's where we differ and you believe that 5% of capacity is a workable figure for maximum charging current.
Again, you managed to convince me that there was evidence a 60A charger was more suited to a 1000A bank of conventional batteries than the lower 400Ah figure (relating to batteries such as AGM). I admit that I assumed that you meant flooded batteries such as Trojan T105 were conventional batteries.
Simple question: Can you please publish the link to the Vectron information you mentioned. I prefer to review a reasonable amount of evidence before making a decision.
Or are you confirming that Sailinglegend420 was correct instead in stating that the charger:capacity ratios he mentioned
I also mentioned that a lot depended on personal priorities usage patterns and equipment. Perhaps your priorities are not very similar to mine. Nothing wrong with that, but knowing why you appeared to suggest a very low charger size would help.
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nigelmercier
RIP
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- Live in Kent, boat in Canary Islands
I have exactly that on my boat: it is not sufficient to recharge the batteries in 12-18 hours, which is what we require.
Mistroma
Well-Known Member
Thanks, I'm a bit better off with 40A, about 9% of domestic bank. However, I'd like to reduce generator running time without knackering the batteries. My own calculations were showing that Trojan were happy with a 60A charger (13% of capacity, but more like 12% when account for losses, parasitic loads etc.).
Another thread initially seemed to indicate that my charge/discharge regime would completely knacker the batteries. However, a little digging soon produced evidence that wasn't the case. All that was meant was that my regime wasn't ideal but it was about as good as I'd get with my current lifestyle. Battery life of 5-6 years seem to be a reason expectation when all factors I'd mentioned were taken into account.
I'm just wondering if this will turn out to be a similar case of "best case" versus "what I can manage" whilst actually achieving reasonable lifespan.
My main problem isn't the number of days at anchor. It's the re-charge bit when having to run a generator back to 85% and then the odd marina day trying to get 100% again. I suspect it's a common problem.
I'm unlikely to buy Sterling though.
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GrahamM376
Well-Known Member
We manage OK 24/7 with 200w solar + wind genny and get higher charge voltages than when running the engine, not UK based though.
sailorman
Well-Known Member
Well for good or bad Mr Sterling has had almost 5,000 hits here. that will certainly show up on a search engine. i hope he gets the advertising he expects
contessaman
Well-Known Member
I think we have established that those in the market for a safe shorepower unit, who want anything resembling customer service should not buy from sterling. It was a south african lady at sterling I dealt with some years ago when I was duped into buying another charger. She was not at all helpful. Lesson learned, 'nuff said.
At a risk of diversifying this thread even further, since there seems to be so much debate on multi-stage charging and getting ones batteries that all important last bit of charge from 90% to 100% full, can any of the experts out there advise me what is or isnt going on with my batteries with this maplin solar regulator that I have?
http://www.maplin.co.uk/dual-16a-solar-charge-regulator-266145
Its not a multi stage regulator, I believe its quite crude. I think it kicks in when the voltage drops below something like 13.8v and disconnects the panel from the battery when they hit 14.4v.
So what does this mean? Are my batteries never fully charged? am I boiling them? I have not had any problems or a lack of charge to date.
I do think my lucas ACR alternator could do with a modern charge controller! the old regulator is rubbish. Theres some kind of hysterisis in the system the charge light wont go out until you hit 1800 rpm on the engine but once its gone out it then stays out all the way back down to idle at 700 rpm. Monitoring the volt meter varifies that im not getting any charge until I do this revving the engine procedure. Hey - I wont be buying a sterling advanced alternator controller though!!
At a risk of diversifying this thread even further, since there seems to be so much debate on multi-stage charging and getting ones batteries that all important last bit of charge from 90% to 100% full, can any of the experts out there advise me what is or isnt going on with my batteries with this maplin solar regulator that I have?
http://www.maplin.co.uk/dual-16a-solar-charge-regulator-266145
Its not a multi stage regulator, I believe its quite crude. I think it kicks in when the voltage drops below something like 13.8v and disconnects the panel from the battery when they hit 14.4v.
So what does this mean? Are my batteries never fully charged? am I boiling them? I have not had any problems or a lack of charge to date.
I do think my lucas ACR alternator could do with a modern charge controller! the old regulator is rubbish. Theres some kind of hysterisis in the system the charge light wont go out until you hit 1800 rpm on the engine but once its gone out it then stays out all the way back down to idle at 700 rpm. Monitoring the volt meter varifies that im not getting any charge until I do this revving the engine procedure. Hey - I wont be buying a sterling advanced alternator controller though!!
awol
Well-Known Member
Try changing the bulb to a different wattage!