Conference unifix::sailing

    If you have a Volvo Penta engine,remove the regulator from the
    alternator.At the back of the regulator (where the wires are ) there is
    a small blank wire. (5 mm long) Cut this wire in two and your
    generator is producing 0.7 Volts more. 
    
    
    Peter

    If you have remote sensing from your regulator, it should go beyond
    the isolation diodes. This will effectively compensate for the 0.7v
    forward drop on the diodes. I believe the diodes are normally used
    to go around the battery switch and directly into the batteries, and
    the switches are used to switch battery output only. This gets
    around the problem of possibly opening the load on the
    rectifier diodes and having them pop.
    
    This is all textbook knowledge. Anyone else want to comment?
    
    Bill
    
    
    

If you haven't already done so, see Note 3.18 for a list of other notes
on this subject. 

Yes, the roughly 0.7 volt drop across the isolator diodes is
significant. The output voltage of most alternators is not adjustable.
Remote sensing regulators are not usual. The output voltage of a normal
regulator is a compromise between fast recharging and not over-charging
with the emphasis strongly on not over-charging. With our OEM
alternator/regulator it would takes literally hours of engine running to
even approach full battery charge. Reducing the charging voltage by 0.7
volts will do nothing except badly under-charge your batteries and
greatly shorten their life. If you use an isolator, you must increase
the alternator output voltage. Ample Power (and others) make adjustable,
remote sensing regulators (about $170 plus the expense and hassle of
installation). I've been delighted with my Ample Power alternator and 
regulator so far. 

If you use an isolator, the isolator input is connected to the 
alternator output. The isolator outputs are connected directly to the 
battery positive terminals. Thus the alternator is always connected to 
the batteries through the isolator. The battery switch allows selecting
which battery supplies the engine starter, electronics, etc. Other 
schemes are possible and have advantages (see other notes).

Alan

    
    re; .1
    I have a Yanmar diesel.
    
    re: .2 
    I don't see any regulator; is it part of the alternator?
    
    re: .3
    Your purchase sounds interesting. But is there a way to increase the
    alternator output?
    

re .4:

These days the regulator is usually integral with the alternator. It may 
be entirely inside the alternator case or it may be (as on our OEM 
Lucas) a small black box on the back of the alternator. The components 
are likely sealed inside the case and are non-repairable.

The usual OEM alternator has a maximum (cold) output of 45 to 50 amps. 
As the case temperature increases, the maximum safe output decreases 
perhaps 20%.

The rated output of the Ample Power alternators (for example) is at a
case temperature of 200 deg F. It is not difficult to draw so much
current from an alternator that it will overheat to the point of
self-destruction. The list price of an Ample Power 100A alternator (not
including regulator) is about $370. Add to this $170 for a regulator, a 
couple of ammeter shunts (about $40 each), a good digital voltmeter (eg, 
a Fluke 73 at about $80), various cables and other miscellaneous bits 
and the price is over $700 before any discounts. But then you have a 
very good, reliable, high performance battery charging system. And if 
you're going to spend this much, you might as well get a couple of
really good batteries, say Prevailer gel batteries at $180 or so each. 


There is one bright side to all this ...... if you decide to buy another 
boat someday, all of these nice pieces will work just fine on the new 
boat. Just put all the OEM stuff back on your present boat. The buyer 
will never notice. 

Alan

    re:.5
    I don't want to spend that now, but I will call Ample Power to get
    information.
    
    After revisiting the isolator, battery switch hookup, and drawing some
    possible circuits, the isolator does not do what I expected. I thought the
    isolator protects the good battery from loosing power to the drained
    one when I put the switch in "BOTH".
    
     

    
    I'm not an expert in circuitry, but if its an isolator, its
    there so that one cannot drain the other. No challenge here
    but are you sure??
    
    JIm

    RE: .-1
    
    The use of the isolator is purely to isolate the charging circuit so
    that a single alternator can charge two batteries simultaneously.  Has
    nothing to do with load.
    
    When the battery switch is in BOTH, then both batteries are feeding the
    same load and, by definition, the higher charged battery will drain
    into the lower charged battery.
    
    The purpose of the BOTH position on the switch is to give you
    emergency power when both batteries are too low to start your engine by
    themselves.  It is kind of a last resort.  You should never put the
    switch in the BOTH position on a regular basis.  You will always have a
    difference in potential from one battery to the other and not optimize
    the charging (or life) of the batteries.
    
    I have an isolator and an Ample Power 3-step regulator.  I only have an
    80-amp alternator, but have never had any problems.  Installation of
    the regulator is pretty detailed and must be done exactly to
    instructions or poof, you're out a lot of bucks.  But operation is
    automatic and the value of knowing your batteries are at full charge is
    tremendous.
    
    Good luck,
    Jeff
    
     

re .8:

Using batteries in parallel is fairly controversial, it seems. Many 
argue against it, but some say it is acceptable.

If your alternator output is connected to the main power bus and the 
battery selector switch is in the BOTH position when battery charging, 
then both batteries will be charged simultaneously. The current into a 
battery being charged depends on how discharged the battery is (for a 
given charging voltage). When charging two batteries in parallel, the 
more discharged battery gets more current than the less discharged 
battery. Both batteries do get charged. For the usual single fixed 
voltage alternator regulator, the charging voltage is such that the 
alternator is producing much less than its maximum output current. 
Moreover, the charging rate is very low to avoid overcharging because 
with a conventional regulator it must be assumed that the alternator
will be running for hours, even days. 

With our OEM alternator, it would take hours of engine running to fully
charge a battery because of the low charging current. It really makes
sense to parallel batteries during charging to get the maximum amount of
charging for the least engine running time. We charged our batteries for 
years using the battery switch in the BOTH position. It seemed to work 
fine.

The big problem with using batteries in parallel during discharging is 
that you risk completely discharging both at the same time. 

Either Ample Power or Cruising Equipment says "no problem" to using 
batteries in parallel. The other says you shouldn't (as I recall). I've 
decided to go around the whole issue by using an isolator and remote 
sensing alternator.

Alan

Oh, yes, you could use isolator diodes to keep one battery from 
discharging into the other. But there are two problems. First, there is 
a 0.7 or so volt drop across the diodes. This is make the batteries look 
more discharged than they really are to electronics, running lights, 
etc. But the big issue is that engine starter motors draw 200 to 500 
amperes. Diodes with this current capacity are expensive.

    
    maybe i mis-understood. several notes back, an isolator was mentioned.
    also  mentioned was that it was "confusing".
    
    an isolator to me is a device containing isolation diodes.
    
    was this the beast or something else..
    
    JIM.

    .9 hits it right on.  I can't imagine why one shouldn't use the both
    position on a regular basis EXCEPT when the engine is off and one
    wants to avoid running both batteries down.  Its a falicy that a 
    charged lead acid battery will significantly recharge a paralleled
    discharged mate. The difference in voltage between the charged and
    discharged battery is insufficient to recharge the dead battery.
    However, as .9, said the alternator can recharge BOTH batteries in
    parallel. 
    
    Jeff G.

    Getting back to the isolator issue, I believe I understand its role.
    
    Since my unit is one piece, I can only isolate the charging circuit.
    However, if the alternator is active before I switch to BOTH, I don't
    need the isolator. With an isolator, the lower battery is charged
    first.
    
    My thought was that if one battery had the internal resistance to
    bring the EMF to, let's say, 9v, while the other was at 13.5v, in
    a relatively short time they would reach an undesireable equilibrium
    if the switch was left in the BOTH position. With separate diodes I
    believe protection can be achieved.
    
    
    (re: .9 - How long do you have you regulator setup? Is it proven in
     a marine environment?)
    
    
    Thanks for all the help and comments.
    
    b.

    re .12   Batt EMF at 9 volts, WOW, that is one dead battery! I am not
    sure I understand what the problem is with the switch in BOTH.  If
    one batt has a low charge and the other a full charge (I am talking
    about a discharged, not defective battery) there would be no problem
    with the dead battery significantly draining the charged battery with
    the switch in BOTH.  Don't forget, for the alt to charge a lead/acid
    batt the regulator has to be set at 14.2 volts or so.  The 13.2 
    volts a fully NON LOADED battery will develop is not sufficient to
    push much current through (charge) a discharged mate.  As soon as a
    'significant' amperage begins to flow to the dead battery the 'good'
    battery voltage drops slightly due to the load and reduces the
    'charging' current to a trifling amount.
    
    I believe it was mentioned before, DON'T isolate the alternator output
    from both batteries at the same time.  The alt is not designed to 
    operate in an open (no battery connected) circuit.
    
    Jeff G. 

re .12:

I installed the Ample Power alternator and regulator a year ago and it
worked very well all last summer. I obviously can't comment on long term
reliability, yet. Ample Power is one of three competitors in the
sophisticated marine battery charging business. My impression is that
they are the most innovative, and they have a wide range of nifty
products. They've been in business several years, and I did not hesitate
in buying from them. I did, however, get the current shunts from 
Cruising Equipment. Ample Power's systems and components are expensive, 
and it is possible to assemble a very good system using bits and pieces 
from them and others. Ample Power's basic and elegant digital
voltmeter/ammeter is some $350 or so. I adapted a Fluke 73 digital 
voltmeter (<$100) to provide the same functionality. Not as elegant and 
definitely not as user friendly. 

So far I'm a happy sailor. 

Alan

    Maybe no one is now reading this note but I thought I'd add my support
    of the Ample Power system.  I have both the Power Monitor and the
    Alternator Regulator and they work very nicely.  I use a Powerline
    alternator from West Marine (130Amp) which is significantly less than
    the ones offered by Balmar or Ample Power. 
    
    Regarding the battery system and switches, basically, I'd recommend two
    batteries (or banks).  One is just for starting the engine and is a
    high cranking amp battery.  The other is one or more deep discharge
    batteries (in parallel if they are all new and connected this way from
    the start!).  This bank is used for all of the boat power other than
    starting the engine.  The alternator and isolator would provide
    separate charging for each of the two banks.  If the isolator went
    directly to the starter battery through its own single (and relatively
    cheap - from Heller) switch, you would never have to worry about having
    an alternator without a load.  If the switch is off the engine won't
    start.  The normal 1-2-BOTH switch would only be used in the BOTH
    position if the starter battery was weak.  Clearly if it's dead, then
    it should be removed from the system before switching the house bank to
    it.  (reason for good volt meter).  
    
    I installed a very simple and helpful system this winter to switch to 
    BOTH for a few seconds for starting if needed.  It is a starter
    solenoid which is connected to the + side of both banks.  The solenoid
    is turned on with a momentary switch that's mounted with the engine
    controls.  That way, if I need a boost, I don't have to run down, turn
    the switch to BOTH, run up, start the engine, and then run down to turn
    the switch back to the house bank; I just hold the switch that
    activates the solenoid while the engine is starting.
    
    Hope this helps more than confuses.

    I installed the Ample Smart Alternator Regulator (SAR) yesterday.  I
    will try it with the existing Hitachi 55A alternator that came with the
    engine first.  
    
    The alteration to the alternator is straightforward but a bit tricky. 
    The alternator must be disassembled and the brush wires disconnected
    from the internal regulator and run out the back of the alternator. 
    There is not much room to do the soldering and splicing within the
    confines of the case.
    
    The initial checkout was OK.  The only concern I had was the alternator
    was running hotter than I thought it should.  I do not know how hot it
    ran before, so I have no comparison.  I would expect it to run hotter
    since it is now working harder.  
    
    The next phase is to add shunts and measuring to see what is really
    going on.  With that I will decide whether to activiate the current
    limiting on the SAR to keep the alternator cooler.
    
    Has anyone else tried one of the smart regulators with a standard
    alternator?

re .last:

With an Ample Power regulator, it is very easy to overload an 
alternator. The Ample regulator we have (the one before the very latest 
design) does not have current limiting. With it I've seen our alternator 
output rise as high as 75A for several minutes with our three batteries 
perhaps half discharged. This output current would likely destroy a 55A 
alternator (ours is rated at 100A at a case temperature of 200 deg F).
Cruising Equipment sells a 1 mV/A shunt rated for 200A for about $40. 
One of these and a good digital voltmeter (eg, a Fluke 73 -- under $100) 
will allow easy and accurate monitoring of alternator output current and 
voltage. Cheaper than a new alternator.

Alan