On my fourth Alternator?

[goboatingnow]

Originally Posted by Bowdrie

That's OK, many sailors prefer to put all their eggs in one basket.
I mentioned "Rocket Science".
In a well published picture of the cockpit of the space shuttle, you can see on the overhead THREE HP-41 calculators, they obviously were not trusting on only 1 unit.
Yes, that was a long time ago, but the axiom still holds.

well I have solar , mains charger and the alternator , so three eggs and in extremis a honda portable ( which I rarely bother with these days )

I have comprehensive monitoring so dead batteries simply dont occur

[Sailing Hanse37]

Originally Posted by goboatingnow

sure tell a time served electronics engineer whats what , why dont you

when I say what I can get out of my alternator its because I KNOW it and I know how to control it properly to deliver that

you on the other are just reading labels

I never said just couple a stock alternator to a Li bank , I have repeatedly said that all charge sources should be made Li compatible and that's means changing the alternator regulator , whats is nonsense is substituting that proper procedure with a low current Dc Dc convertor

My dear friend i have Phd in electronics the DC/DC converter costs about 10 times less than your solution. We have started a multi year trip with our boat, dreaming of a circum navigation. For us alternator charging is a last resort and for that 20 Amps is more than sufficient. Main charging comes from the solar panels.

[goboatingnow]

Originally Posted by Sailing Hanse37

My dear friend i have Phd in electronics the DC/DC converter costs about 10 times less than your solution. We have started a multi year trip with our boat, dreaming of a circum navigation. For us alternator charging is a last resort and for that 20 Amps is more than sufficient. Main charging comes from the solar panels.

Doctors of EE are far too academic to be practical engineers !!!!

A external alternator regulator costs about $200 for under 100A

It’s a far better solution and support proper alternator charge termination by field coil disconnect and adds temperature protection

Why engineer something arseways simply to avoid touching the alternator it doesn’t make sense. Stock regulators designed fir car power supply usages should never have been on boats in the first place.

[Sailing Hanse37]

Originally Posted by goboatingnow

Doctors of EE are far too academic to be practical engineers !!!!

A external alternator regulator costs about $200 for under 100A

It’s a far better solution and support proper alternator charge termination by field coil disconnect and adds temperature protection

Why engineer something arseways simply to avoid touching the alternator it doesn’t make sense. Stock regulators designed fir car power supply usages should never have been on boats in the first place.

I have known field engineers like you in my career, i will leave it at that.

[mitiempo]

Originally Posted by Sailing Hanse37

.........the DC/DC converter costs about 10 times less than your solution. We have started a multi year trip with our boat, dreaming of a circum navigation. For us alternator charging is a last resort and for that 20 Amps is more than sufficient. Main charging comes from the solar panels.

I agree. If you have good solar (as you should) and are not planning to charge with the alternator unless actually travelling somewhere a DC to DC charger is simple and makes sense. Not very expensive and a 3 wire install.

[Christmas Beetle]

Thank you most contributors. I am a person who has worked in many industries and listening to sales people or a more common terminology these days are called business development people and usually produce unacceptable outcomes.
Whenever i contact organisations in any discipline, i state i need to talk to the techo’s and get any advice in writing including certifications / supporting evidence - sometimes impossible to achieve.
In summary - “lessons learnt”.

[CharlieJ]

Interesting to note that through 110 responses to the OP's original question/statement, he/she has gone dark. Was this a troll?

[B.Babs]

Originally Posted by CharlieJ

Interesting to note that through 110 responses to the OP's original question/statement, he/she has gone dark. Was this a troll?

I am stille here . My guy has a Balmar on order. Thanks to this groupe

[goboatingnow]

Originally Posted by mitiempo

I agree. If you have good solar (as you should) and are not planning to charge with the alternator unless actually travelling somewhere a DC to DC charger is simple and makes sense. Not very expensive and a 3 wire install.

strangely people seem nervous to change or upgrade alternator systems. Maybe people view it as some “ dark art” . So we get all sorts of questionable solutions and “ work arounds” and their accompanying “ justifications “ for indirect charging.

High end high current capable dc dc converters connected between a starter and a Li are a bad workaround. The typically poor quality low capacity starter will endure unwanted cycles or over voltages. Certainly for higher currents 50-100 the indirect dc dc is very expensive and very unsuitable. Condemning your alternator capacity to a permanent low capacity solution seems a very poor decision to me.

[Ballsnall]

Originally Posted by goboatingnow

Certainly for higher currents 50-100 the indirect dc dc is very expensive and very unsuitable. Condemning your alternator capacity to a permanent low capacity solution seems a very poor decision to me.

The guy has a stock 80a alternator which is probably putting out 30a at cruising speed. So yes, ideally an external temperature compensated regulator is the best way to go, but add in the alternator disconnect protection and the DC/DC charger to supply the start battery you are looking at significant cost for a guy who just wanted drop in lithium to work.

He has now opted for a high output alternator so probably a belt upgrade required as well, possibly even more cooling, this won't be a cheap exercise.

The original advice for the op to resolve the alternator failures by using a low cost 30a DC/DC charger was quite valid for his application and anyone else looking to replace LA with lithium and keeping their stock charging system.