split charging Sailing Today

as your charging rates show richard,the longer you run the engine the less effectively you put in,the smart chargers would hold/boost the charge at the max amps the batteries would take for as long as it needs it,depends on charger timer as well.
but the method of splitting your charging times up means you should be getting the 60a into your battery more often ,for longer i am a major fan of smart chargers having used them for about 12 years now. as to the new tecnology going into alternaters it would be interesting to know if they do simulate the same as 3 stage chargers,if they don,t then on a sailboat certainly a smart regulater has to be the way forward.
 
Richard
I would have your alternator regulator checked if it does not output 14.2 volts or more. I had this problem of low output voltage with my Volvo 2002 at about 14 years old, which meant that the batteries never got a decent charge. Local car electrics firm fitted a new regulator for about £40.
 
After talking to Merlin at SIBS I am getting my 11 yr old alternator refurbished and a new regulator fitted (14.4v - apparently being old mine will have a 14v one in) the guy at Merlin suggested £50 quid from an auto electrician.

He also said with this done I would be better off binning my Sterling Advance Regulator unit as it wouldn't help any - don't know how true this is?
 
I wonder if we were talking to the same Merlin chap. Given the fact that he could have made more money, but chose not too, holds a lot of sway for me.

Update: Just checked the current PBO and the chap that served me looks very much like the Technical expert in the Ask the expert column, James Hortop. Would be good if PBO could get him to clarify some of the science behind regulators as he clearly is qualified to explain.
 
A lot depends on alternator type. Some have combined regulator and brush box, held in by 2 screws, two minutes to change, and a lot cheaper than £50. Some are internal, lot more problem and cost.
Also check with the dealer that the new one is a higher voltage one, can depend on the supply source, LSUK are a good place to try.

Brian
 
My first comment is that once upon a time Lawyers were seen as the profession least trusted. To my mind that has been vastly outstripped by journalists. In almost every aspect of all media the journalist claims indirectly to be be the expert on the subject, only he covers all subjects.

I think it is a great tragedy that they have so much influence over our thinking while in fact they are subject to commercial pressures a desire to appeal to the masses and their own ignorance/prejudice.

Anyway getting onto battery charging, yes to charge for 6 to 8 hours a day is bad.

I think it is essential that if you are running an engine to charge a battery then you at least have an amp meter to tell you how it is going. It is probably worth stopping charging if the rate falls to a fraction of the starting current cos the returns get less and less.

For recharging we want current into the battery. Current into the battery depends on battery size battery state of charge and the charging voltage. All this assuming the alternator can supply the current the battery will take. (not often a limitation)

The current into a battery falls dramatically as it gains charge. The 3 stage chargers increase the voltage to get more current in quickly then hopefully reduce the charge rate so that long term charging doesn't boil the batteries. The value is mostly where you do run the engine solely to charge the batteries. More current in for longer means quicker charging.

A VSR is a means of connecting domestic batteries to an engine battery when it is being charged. This can be done with diodes except the voltage drop requires that the regulator produce greater voltage to overcome the inherent voltage drop of diodes. This is in practice most easily done by battery sensing of regulated voltage or of increasing regulator voltage. both of these are difficult with standard alternators such that the smart regulator becomes a viable option because it easily facilitates these requirements. A VSR on the other hand because it has no voltage drop does not require changes to the charging system and voltage. olewill
 
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Anyway getting onto battery charging, yes to charge for 6 to 8 hours a day is bad.

I think it is essential that if you are running an engine to charge a battery then you at least have an amp meter to tell you how it is going. It is probably worth stopping charging if the rate falls to a fraction of the starting current cos the returns get less and less.


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Will,

I think I've reached the point where I'll let the batteries run down to the point where they have used about 30% of capacity, (75Ah), and then charge them until they are up to about 85% of capacity, (adding 35Ah).

From what I can see on the monitor, this should start charging at about 30Ah, and end at about 10Ah.

Anything above 85%, and the input is down to 5Ah and less - as you say, a poor return - the downside being that they will not be fully charged again until I get to a marina in Malta or Gozo, (3 or 4 weeks), when I will also buy one of those Honda 2Kw generators.

I think this is the best i can ask for at the moment, so wont dwell on it anymore. Smart regulators, VSRs, and so on, are decisions which can wait for a while.

On your point about journalists... I havent seen the article, but can imagine that not much can be said in a couple of A4 pages.

I can imagine PBO, doing a similar thing, would select one of the smart regulators, and do an article, or series, on how to fit it, which would be much more informative and useful.

Thanks for pointing out something which was in my subconscious, but needed jolting into my conscious, (if that's the right word).

Richard
 
Try and get hold of a copy of Calder's "Boatowner's Mechanical and Electrical Manual" - I found it invaluable when fitting my electrical system, and it is a mine of useful info and diagrams on boat systems.

If everyone had a copy there wouldn't be so many posts on this forum... /forums/images/graemlins/smile.gif
 
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A VSR

[/ QUOTE ] I found This on the Adverc website.. Biased and with some red herrings maybe but one or two interesting points about VSRs that I had not appreciated
 
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..............Update: Just checked the current PBO and the chap that served me looks very much like the Technical expert in the Ask the expert column, James Hortop. Would be good if PBO could get him to clarify some of the science behind regulators as he clearly is qualified to explain.

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ASAIK he's the boss! Or at least the chief techie. He's also been 'used' by PBO as an 'expert' for years.
Sure he's knowledgeable but you get a Merlin-oriented view of the world from him, naturally.
 
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