Pete the Cat
Sustaining Member
Well I am not sure what you think the difference between many auto alternators and "marine" types- I would say that there is really not all that much difference between a good truck alternator of 100 Amp (with its internal reguator disabled) and your Balmar, technologically, except the very beautiful powder coated case and brilliant blue fan of the Balmar, the absence of an internal regulator and a lot of marketing hype. Your experience sounds quite like what I would expect. (I had a an Ample Power marine 100 A alternator--which is basically a truck alternator with the internal regulator removed--it put out 68 A and more sometimes for a short initial period-- on my Tartan for many years out cruising Central America , but now have an 80A Hitachi stock alternator in which I disabled the internal regulator to accomodate an external smart regulator-- which is virtually identical to many stock alternators installed on Japanese cars these days. It puts out about 60 A for a short period until the smart regulator starts modifying the output against my 400 ah banks. I have an ancient 35a Motorola on my Ericson 32-200 25 XP (I have no idea what it puts out but I would expect it is maybe 20+ amps at full, but without a smart regulator it is going to do that consistently until it hits the feedback limit--what is wrong with that against a 200 Ah bank that is most often 10% to 15% down?) with an internal regulator (essentially a car alternator from yesteryear--most new cars have much larger and more sophisticated alternators with improved internal regulators to support newer cars' increased reliance on electrical technology) with a much smaller bank and load--FYI-- Aside from eating 3/8" belts occasionally seems to do the trick for my overnight and week long trips with a couple 100 ah flooded cell batteries. I have no refrigeration or big loads on the Ericson and I do not make multiple overnight passages (lots of electrical need) with it either. I like the simplicity. I am told that most new cars have more sophisticated internal regulators than in the old "on and off" regulators of days past that undoubtedly is in the guts of my tiny Motorola, but I have not confirmed this with my own autopsy of an example. So that is my response to the car alternator question. Yes, there is not much difference other than those I have noted. I am open to being challenged on this.
Putting out 60% of rated output for the first short phase of your regulator seems entirely normal and and your results seem to prove my point. You are apparently a cruiser who does use much of your usable battery capacity (congratulations--most folks seem to carry excess capacity these days), and accepts that going around with a 15% deficit in charge of your bank is fine (due to the "smart regulator". It might be fine if you are doing passages and cruising to exotic places but that deficit needs to be part of your capacity planning as I am sure you are aware. My understanding is that partially charged batteries do suffer some sulfation issues in flooded cells and that others like full charging to maintain ultimate capacity, but that depends much on their type and how long they remain at less than full charge--I have no information on that in your case. I am not sure what your batteries are and their acceptance and recovery rates are, but in flooded cells you are going to doing a fair amount of gassing and heat there and the heat stresses on everything are substantial--maybe that is a problem and maybe it is not--as I mentioned the defining thing in a system is the acceptance rate of your battery types and their age and I do not know that. I did that kind of cruising once in my life, but am now mostly just a weekend or occasional week long sailor who has a modest electrical budget need and my comments are really directed at folks like me. I have realized that carrying the sophistication and capacity of the systems I used to need for my old usage is silly and self defeating.
I want to qualify my comments here. I am an experienced delivery skipper and cruiser from the 80's who has used high output alternators and external smart regulators since they came out in the 1980s, but I am not an electrical engineer. I generally agree with the theoreticals of people like Nigel Calder, but think he often writes technical things that miss the reality of the actual use that most folks make of their boats. Buying uneeded size and sophistication of systems is a problem that most boaters do not seem to think about. I have thought about writing an article about matching systems to real needs, but the sailing magazines have advertisers want to sell technology and more capacity, not less.
I was impressed by many of the comments early in this thread that suggested going with simple systems. In my travels I saw many cruisers tied up in foreign ports trying to unravel problems with their technology and systems. I would rather be sailing and moving on.
FWIW.
