which high output alternator?

jonic

jonic

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I have a Volvo MD22l 55hp engine (it's really a Perkins) with the standard Valeo 12v 60amp alternator running through a sterling regulator. Having now added a watermaker and other bits for long term cruising I could do with more amps. Can anyone recommend some brands which can be easily fitted bolt for bolt to the existing bracket (and with a single pully) in the 80-100 amp range. Especially interested in reliability and ability to cope with tropical temperatures.

Thanks in advance
 
the sterling will probably be making the 60 amper put out between 80 and 100 amps any way, source charles sterling in an informal chat.
stu
 
Look at Balmar on the Merlin web site, it has its own internal regulator but is better used with one of the Balmar external regulators.
 
[ QUOTE ]
the sterling will probably be making the 60 amper put out between 80 and 100 amps any way, source charles sterling in an informal chat.
stu

[/ QUOTE ]

Did he explain how it increased the output amperage ?
 
My 60amp alternator puts out a maximum of 40 amps with the Sterling regulator. Before I fitted the regulator it never gave much more than 20 amps - battery down to 12.5 volts.
However, I have already had a fan belt break and would be very wary of asking an alternator to give 100 amps with the same fanbelt and pulley!
 
Balmar are good, but expensive. A more reasonably-priced reliable alternative would be the Prestolite Leece-Neville, available in the UK from Adverc and other suppliers. Sturdy heavy-duty alternator with good output at lower revs. I've had a 90A Prestolite for some years, with good results.
 
If the regulator has a ramp up facility it will avoid the sharp loading that breaks the belt and or causes excess wear and slippage. I don't think the Sterling regulator is so equiped.
 
An alternator current rating is limited by the resistance of the windings. The alternator with full 12v applied to the field (rotating coil) gives max magnetic field. The resistance then of the pick up coils means that as you take more current from the alternator the voltage drops. If it drops to 12v then you can drive lights etc but can't charge a battery.

The next limiting factor is the heat generated by the volt drop in the coils. This requires major fan power or the windings will cook.

So if mr Stirling got 80 amps out of a 60 amp alternator I will bet the voltage at 80namps was very low and it was only for a short time before the alternator cooked.

There have been so many alternators manufactured for cars that manufacturers have pared down materials and design to the bare minimum to reduce cost. If the label says 60 amps you can bet that is under the best conditions and even then probably an exageration. Certainly you can never expect to get full current at 14volts out for battery charging.
All IMHO
olewill
 
I dont speak as an expert .... but aren't you looking up the wrong end of the telescope?

Lets say we start with your daily consumption and its say 100 amp hours plus or minus 50%. If you are relying on your alternator to deliver this then you are condemned to running your engine for an hour or three a day. This will very quickly polish your bores and cause you loads of other problems.

Surely you should be looking to either reduce your consumption or balance it to a large extent by solar or wind generated amps?

If you can't do that then the only route in a genny and with current diesel prices -as the man says "you don't want to do that"

Speaking from my own experience - like you you I am currently in the med - I am finding 2 x 85 watt solar panels are meeting my needs (backed up by a Rutland 913 ) except for in high summer when the bl**dy fridge insulation shows its limitations and the fridge goes into pretty much a 100% duty cycle during the day leaving me naff all left over to run the water maker. Still it gives me a major project for the winter......

As a footnote I get really fed up sharing an anchorage with people that run their engines / generators all night to keep the AC/Fridge/Freezer going. The resultant noise seems to defeat the point of being in a peaceful anchorage to me - but then again I am probably missing something /forums/images/graemlins/frown.gif
 
[ QUOTE ]
I dont speak as an expert .... but aren't you looking up the wrong end of the telescope?

Lets say we start with your daily consumption and its say 100 amp hours plus or minus 50%. If you are relying on your alternator to deliver this then you are condemned to running your engine for an hour or three a day. This will very quickly polish your bores and cause you loads of other problems.

Surely you should be looking to either reduce your consumption or balance it to a large extent by solar or wind generated amps?

If you can't do that then the only route in a genny and with current diesel prices -as the man says "you don't want to do that"

Speaking from my own experience - like you you I am currently in the med - I am finding 2 x 85 watt solar panels are meeting my needs (backed up by a Rutland 913 ) except for in high summer when the bl**dy fridge insulation shows its limitations and the fridge goes into pretty much a 100% duty cycle during the day leaving me naff all left over to run the water maker. Still it gives me a major project for the winter......

As a footnote I get really fed up sharing an anchorage with people that run their engines / generators all night to keep the AC/Fridge/Freezer going. The resultant noise seems to defeat the point of being in a peaceful anchorage to me - but then again I am probably missing something /forums/images/graemlins/frown.gif

[/ QUOTE ]


I too have a Rutland 913 along with Solar panels charging a 300ah bank. Prior to adding the watermaker this was fine. However the watermaker is an echotech with a 30-38amp draw.

On a cloudy/light wind day with the watermaker, fridge and say an autopilot on, the alternator has very little left in reserve and is working too hard.

As others have said rated output of the alternator often does not match the true figure. Best output from my 60amp is 43amps. Higher output would give me enough to run the consumables and a decent net charge into the battteries, reducing runnning times.

I have a Honda genny as well, but am loath to use it at anchor.
 
Absolutely correct William. You can't get a quart out of a pint pot and trying to set up a smart regulator to get more out of an alternator than it was designed to give will cook it. I agree also with PVB that a Prestolite from Adverc would be a good replacement (look at their website) My old 50 amp on a Vetus/Mitsubishi 32HP cooked and I replaced it with a 90 amp Prestolite. Performs very well but I would not fit one of higher amps than this without twin belt drives. Unless I keep my single belt pretty tight it squeals like a scalded cat when the stirling kicks in on boost charge!
 
I recommend looking at the Balmar web site. In my limited experience the Balmar quality is excellent and although quite expensive, well worth the money, especially if you pay in $s and import from the USA. Alternatively, just get a second Volvo alternator kit. That is really simple and works well although you will need something like an X-Split and a new twin controller to get the best out of it. Fair winds.
 
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