Bukh DV20 - charging, alternator, improvement

freebird1

freebird1

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My elderly Bukh DV20 is fitted with the standard Marchal 38 amp alternator. Recently, I accidentally discharged one of my 110 amp hour batteries having left a light on all night. The battery refused to recover by engine charge alone. The resting voltage would not budge from 11.68v. However, on the mains charger, I have got it back to 12.6v at rest.

So -
Has anyone upgraded their alternator? Space is very tight and it seems that new brackets / belt may be needed to fit anything bigger in.

Has anyone tried a Sterling Regulator or similar and was the effect worth the expense?

Which would you go for and why?
Thanks in advance.
 
I fitted a Sterling regulator to my S26 last year. It is definitely an effective way of getting more charge into the batteries. The problem is that most alternators are designed for the automotive industry where battery demand is very different. The internal regulator of an automotive alternator is "set" to prevent overcharging a car battery when demand can be very low but the charge continuous. On a boat the demand can be high when you want to recharge a drained battery but the charging rate is limited by the regulator and the total charge is ultimately capped. With a regulator such as a Sterling, the peak charge rate can be much higher (if the alternator is up to it) and the total charge is also greater (more amp hours) because the charge voltage was higher.

If you look at the Sterling web site, there is a downloadable document describing the whole process.

The alternator you describe sounds fairly low capacity - yo may also need to think about uprating that.

Morgan
 
An alternative to the Sterling is the Adverc. We've had one of these on our last two boats, and it would be the very first thing we'd put on any new boat.

It'll keep your batteries in excellent condition even if, like we did, you're full time cruising. Superb company back-up and assistance too!
 
Reply not specifically directed at you Ken but:
I think the point about Kadeena's experience is not so much that the maximum current rating of the alternator was too small but that it was a "standard " alternator regulated to something of the order of 14 volts. Some batteries, if run flat for some reason will not charge from such a source. I suspect it would not have made any difference if it had a maximum current rating of a zillion amps it would still not have worked if it was regulated to 14 volts.

His mains battery charger may have been some smart device that was able charge from a higher voltage, or it it may have been a simple non frills, no whistles, no bells one like mine which has a no load voltage output in excess of 16volts.

A smart alternator regulator may well have enabled the existing smallish alternator to charge the battery.

There are times, and I think this was one of them, where a smart regulator on a small alternator would have achieved what a larger capacity alternator with a standard regulator would not.
 
Did you find the Adverc easy to fit??

I gave up because we (Adverc and myself) could not even identify the alternator type on my old Bukh 20.

My thoughts were to get the local marine mechanics to install the Adverc. They presumably would be able to indentify the alternator and get the appropriate model of Adverc.

Myalternator might be the same make and output of the poster of this thread. Is there any mileage in fitting a bigger alternator, or is it better to add one of the charging regulatirs such as Sterling or Adverc??

MJ
 
"old" Bukh 20's were fittted with Marchal (Motorola) A14/30 or 14/35A alternators with either a F14V or T14V voltage relay (regulator)

DV24's were fitted with a Paris Rhone 50A jobbie - can't remember the exact model number at the moment but It will come to me eventually /forums/images/graemlins/grin.gif
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Artificial Intelligence is no match for Natural Stupidity
 
[ QUOTE ]
Has anyone upgraded their alternator? Space is very tight and it seems that new brackets / belt may be needed to fit anything bigger in.

[/ QUOTE ]Yes - check out this site and look up products, alternators and have a look at the ALT 2 and ALT 3 range - small units with high outputs and dimensioned drawings so you can find the largest that will fit. (the ALT3 is a direct replacement for the Paris Rhone fitted on the DV24)[ QUOTE ]
Has anyone tried a Sterling Regulator or similar and was the effect worth the expense?
Which would you go for and why?
Thanks in advance.

[/ QUOTE ]Yes and Yes - started off with the Sterling regulator wired into the original Paris Rhone alternator. Marked improvement - alternator puts out its full whack for much longer than before - only drawback is watch the electrolyte level - heavy (deep) discharging and fast recharging consumes a lot more water than when running on the alternator's internal regulator.

If fitting the sterling do fit a cut out switch in the sense lead (yellow IIRC) so you can "switch off" the sterling unit - handy when engine is cold and the leisure batteries are flat!
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Artificial Intelligence is no match for Natural Stupidity
 
Plenty of room to fit a bigger output alternator to a BUKH 20. The external dimensions of the alternator itself do not seem to increase significantly as output increases.
There are 3 basic types of alternator securing arrangements depending on the 'feet' arrangement. You have to match the right one obviously. Westmarine catalogue has a good description/article on the diffferent types.
The next issue is whether to fit a marine double insulated alternator which is usually considered appropriate in a marine environment where there could be propane or petrol fumes (one would hope not!) and this type should eliminate risk of sparking. The much cheaper alternative is a car type (I use a GM refurbished 60amp output which I have used for about 3000 hours and it only cost £25!
Anything much bigger than 75amps will need a twin belt drive to avoid slippage. This would require significant modification!
I have had two smart controllers of a well known make, one of which failed unsafe rather than safe ie voltage went higher than 14.4 to 16plus. The result was to damage batteries and the alternator.
The disadvantages of a smart controller are the much higher use of battery water (on lead acid types). I also suspect the frequent use of high output of the alternator shortens the alternator life AND the battery life. The advantage of better use of available battery capacity may be worth it. Personally, I have abandoned a smart controller but make good use of solar panels to condition my batteries.
 
Interesting point about making better use of the space. I asked about this as I have a choice of 4 freebie alternators and not one will fit the space available on the current mountings. I can add additional brackets to accomodate and move the bracket around the fly wheel a bit to a spot where there is room for any size alternator.

Thanks for the comments so far everyone.
 
[ QUOTE ]
Did you find the Adverc easy to fit??

I gave up because we (Adverc and myself) could not even identify the alternator type on my old Bukh 20.

My thoughts were to get the local marine mechanics to install the Adverc. They presumably would be able to indentify the alternator and get the appropriate model of Adverc.

Myalternator might be the same make and output of the poster of this thread. Is there any mileage in fitting a bigger alternator, or is it better to add one of the charging regulatirs such as Sterling or Adverc??

MJ

[/ QUOTE ]

Hi Mark,

Yes, I've fitted Advercs to around 12 boats (at the last count!) and have only had identification problems with the alternator on one. Discussed this with Adverc via email (we were in the Med.) and got it sorted.

It may be easier and cheaper to simply change the alternator. Not as difficult as it sounds. I changed the original Paris-Rhone on our Bukh 20 for a fully reconditioned standard Lucas 70 amp car one that I bought from our local alternator and starter motor specialist. It cost £25.00 with the P-R traded in and I bought a second recon. one for £45.00 - there was no trade-in on that one. Both prices were a few years ago now though, so will be higher now. You certainly don't need a so-called 'marine' type.

We got two because we were about to shove off cruising (we were away for almost ten years) and we wanted a spare. In the event the spare was never used on the B20, but has now been fitted to our new B24. You will need to modify the fan-belt adjusting strut though.

It is incredibly simple to fit the Adverc system with this and most other alternators. We've found that the 70 amp output - allied to the Adverc controller - provide ample power for a liveaboard life.

So depending on how old your alternator is, I would go for a reconditioned one of around 70 amps (ours looked and performed just like a brand new unit) and fit the Adverc. You won't regret it I assure you.
PM me if you decide to go this route and I'll give as much help as I can. /forums/images/graemlins/smile.gif
 
Jerry,

Many thanks for the reply and useful info.

I will make it a winter project to add the Adverc controller.

I will give thought to changing the Alternator. I only have a 110 and 80 amp battery bank. Thus not sure about the bigger alternator.

But we do have a fridge plus radar to feed. At anchor in the Scillies, we run the fridge on its minimum setting, and run other electrics sparingly. The battery gets its hour or so charge a day, but without the controller, most of the hour is as if in a tidal gate!!

When enquiring from Adverc, we found it difficult to identify the alternator, only because I was to feeble to take it off and read the writing on the back.

Will get back to you later in the year if thats OK.

Mj
 
Hi Mark,

Ah, not removing it explains it! I've never known the guys at Adverc to be stumped, so I'm sure they'll be able to sort out your existing alternator when you get the name/number of it.

No problem at all contacting me later in the year!

Enjoy the rest of this pretty dismal season! /forums/images/graemlins/smile.gif

Jerry
 
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