Upgrading alternator.

Csail

Csail

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We have loads of kit on board including fridge, heating, inverter etc so thinking of binning the 50A alternator that has to charge eng. start battery and x2 110Ah domestics so from the reply below what is the best option?


Thank you for your enquiry.

I have checked the engine spec and can advise as follows:

1) Replace existing 50 amp alternator with 70amp alternator. Supply new
70amp alternator/fan/pulley and new mounting bracket. Runs on existing
3/8" pullies & single 3/8" belt. 105.00 + vat = 123.38 Note. An increase in
fan belt wear/decreased fan belt life may be noticed with this option
and must be borne in mind.

2) Replace existing 50 amp alternator with 100amp alternator. Supply
new 100 amp alternator/fan/pulley , new mounting bracket, oversleeve
crankshaft pulley, new water pump pulley, new 1/2" belt. Runs on new single
1/2" drive pullies and belt. 195.00 + vat = 229.13

Carriage 12.50 + vat = 14.69

Please call me should you wish to discuss further.
 
[ QUOTE ]
what is the best option

[/ QUOTE ] The better option, by far, is the second of the two. I just costs a lot more. You might also want to upgrade the wiring from the alternator if it is to handle 100amps instead of 50 amps.

Even better will be to include some sort of smart regulator I would think

Goodness knows what the best option will be. An independent generator maybe.
 
Upgrading the alternator isn't the best answer. With only 220Ah of domestic batteries, you'll be lucky ever to see much more than 50A charge - ordinary leisure batteries simply won't accept any more. You can ignore the starting battery, this takes minimal charge.

For the first step, you have a choice: either add extra batteries to your domestic bank, or add a "smart" regulator (Adverc, Sterling, etc) to your alternator. In terms of cost-efficiency, adding 2 more batteries would be my first choice, followed by the smart regulator. You may well find that doing both will improve the system enough to cope with your needs. If you're still having problems, by all means then upgrade the alternator, but bear in mind you must have sufficient battery capacity to accept the alternator's charge. It's no good just fitting a 100A alternator unless you have 500-600Ah of batteries to soak up the potential charge current.

A good thing to have is a battery monitor which shows the Ah taken from the batteries and shows how quickly charging is taking place. However, I'd put this in third place on the shopping list after extra batteries and a smart regulator.
 
Your equipment sounds very similar to ours, with the same size batteries. We have about 70 Watts of solar power but we run the fridge 24 hours per day for six months. Having a Sterling controller has made a big difference to us, the batteries charge to a higher voltage in a far shorter time than previously. Our alternator is the standard Yanmar one, 55 A I believe.
 
[ QUOTE ]
The current setup is via X-split charger (whatever that does) and also Aero4gen.

[/ QUOTE ]The X-split is just a low-loss diode splitter, to stop the engine battery getting discharged. If you have an Aerogen as well, I'd certainly go for more batteries first.
 
Increase the ampage of your domestic batteries and get a Balmar marine alternator and smart charger.

I know its expesive but it works and is reliable.

Don't run it underwater for more than an hour though, they get upset and fall over /forums/images/graemlins/blush.gif !!!!
Still I did replace it with another one and it working fine - really is the dogs dangly bits /forums/images/graemlins/smile.gif
 
You really need to know how much current your existing alternator is delivering (in practice) before you think of replacing it with a larger one.

My guess is that ity is not supplying anything like 50 amps even at the start of battery recharging.

Usually the limiting factor on charging current is the batteries. More batteries equals more charging current. So the simple answer is another battery in parallel. With the advantage that batteries are not discharged so much or you have more time of use before recharging.

The charge current can be increased however with the use of smart charger. This may bring the charge current up to the point where the alternator is the current limiting factorbut that ill only increase charging time a little as the charging current into the batteries will still fall with time into the charge cycle.

An under sized alternator will also get hot and may have a shorter life if it is ran at full current for long periods. But like I said you need an amp meter to see what it is really doing. Then make the decision.

I don't think you will get enough bang for your buck simply putting in a bigger alternator. good luck olewill
 
Had similar setup and changed it by adding smart regulator, brillant and more batteries.

The smart regulator Adverc or sterling, I have used both with excellent results. What this bit of kit does is extract the optimum from your alternator in the best way for you battery bank.

There has been loads of advice on here but what with the search engine not working, you might need to start new threads.
 
Many alternators fitted in old boats have an integrated regulator. How would you fit a smart charger in such a device? For example my engine has a Motorola NGM V14 75A. I agree with you that it would be a good idea to have a smart regulator but I feel quite uncomfortable in tampering with the field coil terminals. Anyone of you actually did it?
Daniel
 
[ QUOTE ]
I feel quite uncomfortable in tampering

[/ QUOTE ] If you are not happy about altering connections to the innards of your alternator or feel your soldering skills are not up to it get an automobile electrician to do it for you.
 
[ QUOTE ]
If you are not happy about altering connections to the innards of your alternator or feel your soldering skills are not up to it get an automobile electrician to do it for you.

[/ QUOTE ]
No, my soldering skills are quite good and, according to my experience and my job, I am usually more skilled than the average automobile electrician (I am an "experienced" experimental physicist). I would just appreciate to hear practical advices from somebody who actually did the job himself (or herself).
Thanks, I will look at the recommended web site.
Regards
Daniel
 
I might have missed the power of your invertor but if more than 1200 W makes sense to have 100amp+ (perhaps Balmar) alternator. Merlin have them for £265 (ex VAT) if that helps.

Merlin

John

PS Re upgrading suggestions: If doubts about your soldering abilities Balmar comes with built in plug to add external smart regulator (many types, most about £200).
 
[ QUOTE ]
I would just appreciate to hear practical advices from somebody who actually did the job himself (or herself).

[/ QUOTE ]

By coincidence, just did the job yesterday on a DELCO alternator. (have done other types before). Alternator came apart a dream (not always the case). There are usually just three bolts holding the two parts together. TIP: mark the casing so you get the two halves back together in the same orientation.

I cleaned up the field rotor slip rings with finest grade emery. Checked the brushes which were fine. There was even a suitable hole right by the appropriate field brush to lead the new control wire out! In fact I decided it was easier and stronger to use a crimped connection rather than soldering in this particular case.

Try to use some nice flexible heavily insulated wire, give it some extra protection where it passes through the case, and provide strain relief.

When you reassemble, you will need to keep the brushes compressed in their housing. There will be a hole/slot in the brush holder and a hole in the casing. Insert a piece of stiff wire to do this. Don't forget to remove once reassembled!

(NOTE: if you have an alternator such as a PARIS-RHONE with a detachable regulator/brushholder at the back the job is of course much easier).

Vic
 
Thank you very much Vic,
this is the information I needed. Overall not too difficult!
In the meantime I found more precise data on what I have: the alternator is a Motorola, series NGM 14V 75A (approx 1985) with integral regulator. The smart regulator I bough few years ago (approx 1995), never used and plan to install now is a Balmar ARS-III. Two questions: 1) are both P-types? I think so but I am not sure. 2) is the ARS-III still considered a good regulator? Since its production there have been many changes, including digital control so I wonder if it would be more reasonable to go for a new generation regulator even if the cost is not negligible and dumping the never used ARS-III would be a pity. I'd like to hear from somebody who has got a working ARS-III in his engine.

Regards
Daniel
 
Daniel,

I can't answer whether your alternator is P or N type, but it is very easy to work out once you have the alternator apart. Clear instructions are on the Merlin website under their 'AMS smart controller' at:

http://www.power-store.com/view-item.asp?itemid=1288&id=47&

>Downloads>Installation Manual

Generally American alternators tend to be P and European N. Unfortunately Merlin list most makes except Motorola!

I do not know the BALMAR ARS-111, but most modern units can be configured for P or N. The instructions should tell you. If suitable I would certainly try it to start with. Indeed, if you understand battery charging and don't mind supervising closely you can achieve the same results as a smart-charger with just a manual (variable resistor) control of the alternator field current. I would be inclined to put the aprox £100 into a battery monitor such as NASA BM-1 first.

Good Luck, Vic
 
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