How to set fire to your boat...

[steve_cronin]

This is a sharing of information to help others who might also start down the wrong road to solve a power problem.

If like me you want to increase the available power from your service batteries you might have considered fitting a "smart" alternator regulator (only OK if it's designed for yachts and NOt an old product intended for ambulances being offered as suitable for yachts)

But, DON'T fit a "charge splitting relay" in place of your splitter diodes no matter how persuasive the salesperson if, like me, you usually have a heavy drain (windlass) shortly after starting the engine in the morning following a night or two running down the service battery.

These relays close to connect the two battery banks together for charging after the starter battery has reached a relatively low (around 13.2 volts) float level and what will happen is that since the service battery hasn't sufficient charge yet, the heavy current required by the windlass (say around 150 amps) will be drawn down the charging wires which have nothing like the capacity. The relay itself might only be rated at 70 or 90 amps. Result: the relay will melt down or if the contacts fuse and/our wiring will get hot, VERY hot and without a fuse in circuit will turn into a heating element. The results are not too difficult to contemplate. You, being on deck organising the putting to sea will be oblivious to what is happening in your engine room until the smoke starts to rise through the hatch.

This is a REAL danger if you run down your batteries over night and need a heavy demand in the morning. However none of the suppliers of these "VSRs" make you aware of it.

Steve Cronin

<hr width=100% size=1>The above is, like any other post here, only a personal opinion

 

[tome]

Steve

I believed that using split charge relays was a well-understood no-no with high capacity regulators, this is from the Sterling installation instructions on the subject:

"...be warned. Most low cost relays in the marine industry are approx 25mm cubed. These relays may have been good enough for your old poor charging system, but when a Booster is used do not be surprised if after a short period of time the relay melts. Use only good quality relays..."

However you are quite right about the possible effects of large current surges in the charging cables and there doesn't seem to be any specific warning on this subject.

Regards
Tom

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[TonyBrooks]

Nearly all you say is correct except perhaps you should qualify that by stating "Lucas". (in view of the figures quoted).

Other manufacturers produce relays that are rated at 200 amps or more, these tend to be called contactors and you probably have them associated with the winch control. There is nothing magic about split charging relays - they are just high current relays with, perhaps, a diode across the coil to damp shut down surges - but I have yet to see such a thing.

Durite make a relay quoted as 180 amps (I have some doubts about the total truth of that though).

I would add - if buying blocking diodes, make sure the rating you select can be obtained under the conditions you intend to use it - consider the true ambient engine room temperature after a while and also consider any requirements for a minimum air flow for the quoted output. If you have to de-rate for high ambient temperatures or lack of air flow things get even more expensive.

We are back to the petrol v diesel debate etc. Find out as m,any of the facts as you can, and make a choice appropriate to you.

Tony Brooks

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[Talbot]

Simple answer is to install thermal cutouts to protect the charger wiring from taking the strain of a 1000w windlass! Here is a method of avoiding the problems you relate <A target="_blank" HREF=http://www.yandina.com/Bank3.htm>http://www.yandina.com/Bank3.htm</A>

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[pvb]

Nothing wrong with VSRs

There's nothing wrong with VSRs (voltage sensitive relays, or "battery combiners") provided they are correctly installed in a properly-planned installation. However, if they are under-specified, or if the installation is wrongly-planned, there will naturally be a potential problem.

In your case, it seems that your alternator output goes to the starting battery, and your VSR links the charge to the domestic bank. But your windlass is connected to the domestic bank - didn't it occur to whoever planned the system that this could easily result in an excess current through the VSR? In this case, a higher capacity VSR would have simply solved your problem - BEP, for example, make VSRs in 50, 90, 200 and (I think) 300 amp ratings.

Many people think that because boat electrics are only 12v, there isn't a lot of scope for danger. But the currents involved can be huge, and represent serious fire danger - as you've said. If people don't understand what they're playing with, they should employ a marine electrician. That way, if there's a big problem, there's someone to pick up the tab.

Incidentally, some US combiner makers recommend that the alternator output should go to the domestic bank, so that the starting battery only gets connected once the domestic batteries have recovered some of their charge.

<hr width=100% size=1><P ID="edit"><FONT SIZE=-1>Edited by kimhollamby on 09/02/2004 08:34 (server time).</FONT></P>

 

[steve_cronin]

What do you mean "...

... "However you are quite right ..."

I AM (Johnny rotten expletive)ing
TOTALLY RIGHT!

On line chandlers and persons with connections to the yachting press ( "...all the products mentioned in this article are available from Wissard Marine" etc ) selling these evil devices through boat shows using persuasive sales staff who's motives are sales volume rather than correct advice to the yachting public, should be censored publically by those very members of the yachting press even ( or especially?)those led by demoted personnel.

This is a major scandal withn very severe safety implications towards the safety of those very dear to us the users of forums such as this and nobody responsible or also aware of the situation should be allowed to hide.

wad'ya think Missie?

Steve Cronin

<hr width=100% size=1>The above is, like any other post here, only a personal opinion

 

[steve_cronin]

Tony, you missed it....

It's the rating of the wire from the relay to the batteries that matters. Also because if you choose a "missmatch" in the table that these dealers in disaster supply AND their agents on this side of the world rely upon, you will choose a 70 or 90 amp relay for the majority of installations then bang or VERY hot wire!. Your premise assumes that the wiring can carry 200amps for which you will need starter cable all the way from the alternator terminal, through the relay to each battery. Do you have such? I doubt it very much.

Steve Cronin


<hr width=100% size=1>The above is, like any other post here, only a personal opinion

 

[steve_cronin]

Why should you when....

.. supposed yachting press "experts" who's (so called!) knowledge and advice are selling these items at major boat shows through their own commercial outlets without checking that their sales personnel are fully acquainted with the dangers of such devices and do not offer the information you put forward?

Steve Cronin



<hr width=100% size=1>The above is, like any other post here, only a personal opinion

 

[steve_cronin]

Excess current

"...it didn't it occur to whoever planned the system that this could easily result in an excess current through the VSR?"

That is the very point!

This outfit from Dorset (and the instructions on their New Zealand originated product) are actually telling buyers to get rid of their to back to back diode set up (thereby becoming the designers of the new system!) and to replace it with this cuboid grey box!

You mention the USA. Are you aware that the ABYC regulations seriosly discourage VSRs on boats for the very reasons I have detailed.

If you're using a diode splitter, apart from switching off the starter battery on VERY long engine runs to avoid over-charging, there is no such danger possible for if the domestic battery doesn't have enough stored energy for your windlass, inverteror bow thruster just won't run. Any voltage drop in a diode is easily compensated for with a proper "intelligent" regulator (which the particular supplier I have in mind does not supply, preferring to offer an old technology timed pulse black box which the very manufacturers of admitted to me only last week was "old technology" and even so SHOULD NOT BE USED WITH A VSR!

Problem is that the Dorset supplier's chirpy salesperson advocates the use of the NZ VSR with it!

Steve Cronin

<hr width=100% size=1>The above is, like any other post here, only a personal opinion<P ID="edit"><FONT SIZE=-1>Edited by kimhollamby on 09/02/2004 08:36 (server time).</FONT></P>

 

[pvb]

Comments explained

As I said in my post, if you don't understand 12v systems, you should leave it to the experts. Apparently you've installed some bits of kit without thoroughly considering the consequences, and then you're blaming the suppliers!

You think it's a coincidence that I mentioned the BEP relay - it's no coincidence, you told us on <A target="_blank" HREF=http://www.ybw.com/cgi-bin/forums/showthreaded.pl?Cat=&Board=pbo&Number=461085&page=&view=&sb=&o=&vc=1#Post461085>26 Jan</A> that you'd bought a "BEP charge splitter relay". That's less than a fortnight ago, so it can't have slipped your mind, surely?

You say that the ABYC regulations discourage VSRs. Go to <A target="_blank" HREF=http://www.abycinc.org/index.cfm>their website</A>, do a search for "vsr" or "voltage sensitive relay" and strangely you'll find no results. The fact is that many hundreds of thousands of US boats use VSRs or battery combiners (essentially a more sophisticated VSR) with no problems at all. Why? Because they're properly installed in properly designed systems.

<hr width=100% size=1><P ID="edit"><FONT SIZE=-1>Edited by kimhollamby on 09/02/2004 08:37 (server time).</FONT></P>

 

[Robin]

I\'m still sorting out

Some amazing electrical gems fitted by a so called professional outfit for the previous owner of our boat. Being paid a high hourly rate does not always guaranteee the knowledge the letterhead advertises. I'm sure that doesn't apply in your case (genuinely) but I applaud any owner who takes the time and the trouble to research the problem himself (or herself) or to ask the forum for advice etc, that is the way to learn, if nothing else to learn enough to question what someone else is being paid to do. If he then passes on what he has learned so that others don't make that same error, then that has to be praised surely not slammed or sneered at.

I thought we were all here to help each other with a common love, point scoring is for work.

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[pvb]

You\'re absolutely right...

Paying a professional doesn't guarantee a proper job, but it does give you a means of recompense if things go wrong. Researching the problem, or asking the forum for advice is, as you say, to be applauded. But making a basic mistake in a DIY installation and then blaming the people who sold you the bits is an entirely different matter.

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[steve_cronin]

Re: Well, Mr Angry...

I was sold a unit that was unfit for it's purposein a bundle of other stuff by people who should have known better.

COME ON. HOW MANY BOATS DO YOU KNOW THAT FIT 200AMP CABLE FROM THEIR SPLIT RELAYS? POUND TO A PENNY YOU DON'T!

I was even nice to the guy in Dorset and, concurrent with stating that I was returning two of the items from the £2000 bundle I'd bought at LIBS. (even thought I'd had to chase up the biggest ones on delivery!) I bought two other items of greater value in compensation. Would you believe though that his son rang back to my office this afternoon to state that I would be charged a 15% "re-stocking fee" for the returned items despite the refund being previously agreed by his sales assistant.

If this sounds like an unfriendly company, make your own judgement but may I point out that (& this MUST be a co-incidence!) its principal is said to regularly contribute to a magazine in the stable of THIS very one, advising on electrics and despite regularly raising a glass "In continuing friendship" does not, in MY experience show outward signs of any such sentiment - as well as purveying potentially dangerous goods!

Don't be personally offended. Anyone can get it wrong without knowing all the facts - feature of forums!

Steve Cronin

<hr width=100% size=1>The above is, like any other post here, only a personal opinion<P ID="edit"><FONT SIZE=-1>Edited by kimhollamby on 09/02/2004 08:40 (server time).</FONT></P>

 

[Robin]

We are ALL right

Or we would not be sailing but gardening at weekends. Just occasionally some posts get as argumentative as at work. The customer is always right, stupid yes but always right, it just means you don't tell him he's stupid but wait for him to work it out for himself.

Not that anyone round here is either always right or is stupid, just that sometimes we need to chill out and sniff the new breeze, we can scupper the buggers later.

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[pvb]

OK, Steve...

If you have a genuine case of grievance, follow it through, if necessary with legal action. Name names. Post their responses. Let us know how the battle progresses.
<P ID="edit"><FONT SIZE=-1>Edited by kimhollamby on 09/02/2004 08:41 (server time).</FONT></P>

 

[steve_cronin]

Advice I was given by

******

Went to the ****** stand for such advice. It was after I subsequently researched the validity of this advice (about which, at the time I registered my scepticism and had it vehemently rebuffed) that the grubs crawled out of the woodwork.

Read the advice of both Adverc AND Sterling on their respective sites re VSRs. "Oh they would say that wouldn't they. After all, a VSR negates a major reason for fitting a smart regulator doesn't it?" The very words of the LIBS stand sales assistant stated on the phone twice later.

Now they want 15% to correct THEIR wrong advice! Johnny Rotten expletive them, I won't pay!

Incidentally, as to experience, I wonder, how many Lucas ACR alternators you've re-built in your life time (and know their major weakness), or how often you've undrcut a commutator with a tool you've made yourself from a ground down hacksaew blade or if you would know how to adjust a third brush generator?

Please, just, ever-so gently, ease yourself off my back.

Steve Cronin



<hr width=100% size=1>The above is, like any other post here, only a personal opinion<P ID="edit"><FONT SIZE=-1>Edited by kimhollamby on 09/02/2004 09:01 (server time).</FONT></P>

 

[steve_cronin]

NOT....

When the buggers have got my hard earned money and want 15% and two lots of carriage to get it back it's not!

Steve Cronin

<hr width=100% size=1>The above is, like any other post here, only a personal opinion

 

[steve_cronin]

What ever....

..gave you the idea that I wasn't?

I just posted the original to try to prevent anyone else from fitting one of these dangerous devices.

Being told that this device wasn't antthing like the split charging relays we used to fit to horse boxes but was a "new technology" completely safe device that was instantly interchangeable with my existing diode block, I was incredulous but took the sales assistant's word for it (after all she worked for a contributor to a major boat magazine).

It was my subsequent examination of the enclosed indecipherable circuit diagram and a better copy downloaded from the maker's website plus the opinions of two leading authorities in the field that my suspicions were raised. The boss of Adverc even told me that Yorkshire ambulances called him in because they had problems with VSRs on reliability aftyer long periods of service battery discharge and he cured it by re-fitting the original blocking diodes.

I have looked into this very thoroughly and am still of the opinion that VSRs don't suit a boat where a heavy wattage demand follows a long period of discharge and a short re-charge time.

This will occur on a boat which moors stern-to in the med or uses it's bow thruster to manoevre out of a berth.

Steve Cronin

<hr width=100% size=1>The above is, like any other post here, only a personal opinion<P ID="edit"><FONT SIZE=-1>Edited by kimhollamby on 09/02/2004 08:43 (server time).</FONT></P>

 

[pvb]

So take Merlin to court....

As I said, if you have a genuine grievance, pursue it - and you'll win. Take Merlin to court (it is Merlin, isn't it?). Keep the forum informed of your progress. We're all consumers, and we can help each other by sharing genuine complaint information.


<hr width=100% size=1><P ID="edit"><FONT SIZE=-1>Edited by kimhollamby on 09/02/2004 08:43 (server time).</FONT></P>

 

[MainlySteam]

Steve

If you think that you have identified a real problem (and I am not contesting that) and from the posts it seems it may have been with a BEP product, why do you not email BEP here in New Zealand with the technical aspects of it. I would be pretty confident that if there is a dangerous situation which they have not forseen, or that their UK representatives are misrepresenting the correct use of their products, they will be interested.

They currently have a page on their internet site on VSR application (currently is <A target="_blank" HREF=http://www.bep.co.nz/showproduct.cfm?productid=518>http://www.bep.co.nz/showproduct.cfm?productid=518</A>) against which you may be able to reflect your concerns against their recommendations.

I have not followed your problem right through, but I think I have a similar potential issue with manual paralleling of our engine and house batteries (they are normally isolated and charged off seperate alternators). While I have not checked, and although the installation was done by a very well respected technician, it may be that if the engine cranking battery, which the windlass comes off, is flat and the house batteries are paralleled in without the engine alternator running, the cable between the house battery supply to the cranking battery supply may not be adequately sized to handle the windlass current - it does not "look" big enough. However, if so, in this case I would imagine that the voltage drop would be obvious at our windlass as the paralleling cable run is reasonably long. It may be that the technician got it right - I must check sometime - but is just something I have remembered not to run the windlass without the engine alternator running if the engine battery is flat. Of course, one should not have to keep such things in mind.

If the items you are concerned about are BEP's, and you contact them, I would appreciate any feedback as to how you get on with them. If the items did not come from BEP, then I guess one could use the same approach with whomsoever they did originate from.

Regards

John

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