What is that? What model and manufacturer? Or is this just a 1980s stupid diode splityter, not really a combiner at all. A combiner is a relay, not a diode.
tachometer not accurate
- Thread starter Hayden Watson
- Start date
My boat is a 1988 C30 with a M25XP which has the 3-bolt crank pulley and I have been in contact with the serpentine belt mfr and confirmed that they have a kit to fit. (edit) I have added a photo of an M25XP with comments about the clearances for a serpentine belt. In a different forum, I have heard from other C30 owners who have gotten the kit to fit the Mk2 XP engines but I will check the clearance between the alternator fan and front wall to be sure.early M25’s won’t accept any serpentine kit. Your crank pulley needs to have the 3 bolt holes for a pto. I don’t know when it was introduced as standard, but not on my 83 and not on @Stu Jackson 34 (87??). Good news is if you can source an XPB crank pulley it should fit.
you can’t turn dow charging voltage with a rheostat. If you tote the regulator will just boost the field to compensate for lower output voltage. It’s called a voltage regulator not a current regulator for a reason.
My understanding of an externally regulated alternator is that the voltage is "regulated" by how much current the alternator is putting out and the internal resistance of the batteries per Ohms law V=IR. During the bulk phase, the internal resistance of the battery is low and so it can accept lots of current (I) and not exceed the set voltage (V). As the battery fills up, its internal resistance increases so the same current will cause the voltage to rise. When the voltage gets to the set point and goes into absorption, the current is limited which has the result of controlling the voltage. The regulator cannot control voltage by any means other than limiting the current so while it is called a "voltage regulator" it is in fact a "current regulator" which is used to limit max voltage.
An alternator will product its max current when the field windings receive max voltage which is in the 12-14v range while charging depending on the state of charge. If you add a rheostat to the field windings, that will lower the voltage in the windings which will reduce the max current. The regulator will try to compensate but it cannot raise the voltage above that of the battery so if the regulator is calling for max current by sending 14v to the windings, and I cut that in half with a rheostat, the current put out should be cut as well.
If I have any of this incorrect, please let me know where I made a wrong turn.
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I do not need a rock steady or even terribly accurate tach. I just want one that does not vary from 1400 - 2400 when I know that I am running at a constant speed of about 1900. Once I get it stable, I will use my optical tach to verify or provide a mental correction factor. In the past, I typically motor at 1400, 1900 or 2200 according to my tach. If each of those are incorrect by a 100 or so I really do not care because I picked those revs based on quietest (1400), smoothest (1900) and max no smoke (2200).
Not sure but I think it is a 1980's stupid diode splitter. It is defiantly not an ACR. It was on the boat when I bought her in 1998 and it has a pretty big heat-sink.
It’s a very common misconception that alternators force a specific current to the battery depending on the charge phase. A battery accepts only the current up to the max of alternator (or battery charger) based on the internal resistance and delta v
there is no direct current control in an alternator/voltage regulator. You get a large current cause the voltage delta is large an the resistance low. All the regulator does is measure the output voltage (at the alternator or battery depending where the sensor is) and adjust the field voltage up or down to get the desired output voltage depending it’s program. When you configure a 614 or other smart regulator (or even a battery charger) the variables you can set are time, temperature and voltage ( no current).
If you want to turn down the charge rate you can heat up the alternators temp sensor if the regulator is not super dumb it will drop output voltage desired to cool the alternator down. This is what the small engine mode switch does on the 614, but instead of heating the alternator, it overrides the temp sensor (grounds the temp sensor IIRC) and fools the regulator into thinking the alternator is hot.
@Hayden Watson ,
Les explained it very well. Your description is essentially backwards. Depleted bank has lower voltage. Bulk is when alternator output is at max current with rising voltage to its setpoint (say from whatever it might be, say ~12.1 or lower and goes up to ~14+ V). Once it reaches that setpoint, current starts to drop off because of battery acceptance at that maximum charging voltage.
Every single MC-612 and 614 installation manual discusses it in depth and quite well. www.balmar.net and download its PDF file. Great read, well done. Maine Sail discusses it in depth on his website, too.
I have written long and often about SMALL ENGINE MODE using Balmar external regulators, my MC-612 and the newer later successor the MC-614. Here are some of those links. They all come from my Electrical Systems 101 collection of boat electrical highlights, which I encourage you to read or re-read.
Electrical Systems 101 Electrical Systems 101
Alternator heat, Regulator Controls, Small Engine Mode
Alternator heat, Regulator Controls, Small Engine Mode
Small Engine Mode - discussion with link to the picture of the toggle switch: Alternator heat, Regulator Controls, Small Engine Mode
Small Engine Mode - the picture of the toggle switch Alternator Output Management with External Regulators [Small Engine Mode]
Using a 3/8" Belt on a Larger Alternator
Alternator Upgrade
This last one ^^^ explains why a serpentine belt won't fit on my C34, although Maine Sail says one can be. I disagree. That particular thread discusses how I use my boat and why the SEM can be used to work with a 3/8" belt successfully. I've been doing it since 2003.
It is a power MANAGEMENT issue, not necessarily a hardware issue.
Your diode splitter is a 1980 piece of technology that you should seriously consider removing because, as we've been saying for the past 30 years it saps voltage from the system when it needs it the most and contributes to chronically undercharged batteries. If you don't want to buy an ACR, then use the B position on your switch ONLY when charging sources are present.
Les explained it very well. Your description is essentially backwards. Depleted bank has lower voltage. Bulk is when alternator output is at max current with rising voltage to its setpoint (say from whatever it might be, say ~12.1 or lower and goes up to ~14+ V). Once it reaches that setpoint, current starts to drop off because of battery acceptance at that maximum charging voltage.
Every single MC-612 and 614 installation manual discusses it in depth and quite well. www.balmar.net and download its PDF file. Great read, well done. Maine Sail discusses it in depth on his website, too.
I have written long and often about SMALL ENGINE MODE using Balmar external regulators, my MC-612 and the newer later successor the MC-614. Here are some of those links. They all come from my Electrical Systems 101 collection of boat electrical highlights, which I encourage you to read or re-read.
Electrical Systems 101 Electrical Systems 101
Alternator heat, Regulator Controls, Small Engine Mode
Alternator heat, Regulator Controls, Small Engine Mode
Small Engine Mode - discussion with link to the picture of the toggle switch: Alternator heat, Regulator Controls, Small Engine Mode
Small Engine Mode - the picture of the toggle switch Alternator Output Management with External Regulators [Small Engine Mode]
Using a 3/8" Belt on a Larger Alternator
Alternator Upgrade
This last one ^^^ explains why a serpentine belt won't fit on my C34, although Maine Sail says one can be. I disagree. That particular thread discusses how I use my boat and why the SEM can be used to work with a 3/8" belt successfully. I've been doing it since 2003.
It is a power MANAGEMENT issue, not necessarily a hardware issue.
Your diode splitter is a 1980 piece of technology that you should seriously consider removing because, as we've been saying for the past 30 years it saps voltage from the system when it needs it the most and contributes to chronically undercharged batteries. If you don't want to buy an ACR, then use the B position on your switch ONLY when charging sources are present.
The Balmar's also feature Belt Load Manager (formerly called Amp Manager) which is an adjustable field control to limit the alternators output or make it compatible with a small belt or to prevent it from cooking itself..
Ok Maine, I can except that I am "not even close" as a possibility because it has been several decades since EE200. I am not trying to be argumentitive and just seeking factual clarfification to my understanding of how the system works. Can you please elaborate and educate me? My questions are
- Am I correct in that the only "control" output produced by the external regulator is the voltage and/or current supplied to the field windings? If this in not correct, what other control does it exert. I am not asking about resulting inputs of other actions but the actual causal control output. To the best of my knowledge, the voltage in the wire from the battery to the regulator (terminal #9 - Positive Voltage Sense) is a input / sense wire to tell the regulator what voltage is being produced but that wire does nothing to change the voltage other than to let the regulator know what the voltage is so that it can change the field output. In looking at the attached MC-614 wiring description, only connection #4 blue field wire is listed as "output". All of the rest are clearly listed as input or sense.
- Does an external regulator directly control the voltage output of the alternator or does it control the total watts produced and thereby limits the voltage through the power equation P = V^2 / R. To limit or regulate the voltage then is V = √(P / R). R (internal resistance of the battery) is a variable resistance based on the battery state of charge and state of health and not controlled by the reg, so to limit volts to say 14.2v when the battery is nearly full and the R is increasing, the watt output from the alternator must be reduced.
- If the above is correct, given that the only control sent to the alternator is the field voltage/current, If you lower the voltage in the blue field control wire, the windings will make a smaller magnetic field and the alternator will put out fewer watts. True or false?
- Lets say that the battery is at 50% SOC and the regulator is calling for max watt output by sending the maximum voltage that it can down the blue wire. If I install a rheostat in that blue wire and add some resistance to that wire, I will reduce the voltage that gets to the windings and the alternator will produce less current because the regulator cannot raise the field output any higher than its max voltage. True or false?
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I have an optical tach but we are not talking about small variation. we are talking about swings from 1400 - 2400 with no change to sound. I can hear a 1000 rpm rev and it ain't happening!
You don't have a Balmar regulator, and don't even need to do what you proposed, with a Balmar. It is already built into the regulator in the form of Belt Load Manager...
But you said that I was not even close so on which points of theory was I incorrect. I realize that the Belt Load Manager will fix the problem but how does it do it? My suspition is that it add a resistance to the blue load wire, thereby reducing the voltage in the windings and the wattage output. If that is not what it does, please explain what is happening.
Hayden,
Continuing in my attempt at humor,
you still have this backwards. Disregard for a moment, if you will please, all the power equations, P = V^2 / R, etc. There are two pieces of equipment at work here: the batteries and the alternator. Two, because I'm excluding the regulator completely, since it doesn't matter whether it's internal or external. Why? Because ALL a regulator does is set a voltage setpoint for the system to reach.It's battery acceptance that at any given voltage will begin to resist the available current flow. This is critical in terms of understanding the process. For example, if you have a gigundous shorepower charger, let's say 200A, and a battery bank, regardless of size, that needs charging. Also regardless of SoC or % full or whatever you want to call it.
For ANY GIVEN VOLTAGE, there is a certain resistance of the battery to accept any more current, called battery acceptance. Because of the chemistry of the batteries were use on boats, the nominal optimal charging voltage has been determined across the industry, i.e., the guys that make these things, to be in the rage of 14+ V for a 12 V bank. This is to avoid boiling off the chemicals in the box.
All the regulator does is set this setpoint V. It does not "tell the alternator to reduce wattage" (actually what we measure as you know is amps). The battery "pushback" does that all on its own. An external regulator simply uses a built in time clock, much like any smart (not really) three stage charger, to change that setpoint after a certain time. External regulators simply check system voltage before they start the clock and do other cross checks, but that's immaterial to the basic concept of how the system works. Don't get caught up in the how until we can agree that you understand the what.
As the amps get pumped in and the bank fills, it pushes back more and more, as at the same time the system V is rising to the setpoint. This is what the graphs in Balmar's manuals and all charger manuals all show: time on the X axis, and V on the right, A on the left. If the setpoint V was lower the A flow would be less, thus taking longer to charge i.e., pump A into the bank, charge it. If the setpoint V was higher, more A would flow, the manufacturers recommend 14+ to stop killing the fluids and boiling them off. That simple.
Once the setpoint is reached, Amps reduce by battery pushback so even if the alternator was 600A, only how much the battery can accept at that particular SoC and V will flow. That's the only reason the A (watts) reduce. Nothing BUT the batteries is "telling" the charging source to do anything.
I leave it to Maine Sail to explain the how of regulators, but it seems to me that this basic understanding of how charging works is important, even if you get the answer you are reasonably requesting. I'll go re-read my Balmar manual again, too.
Have you read one?
Stu, no disrespect intended but on the conceptual basis, your explanation is reverse of cause and effect. The battery does not push back and slow the alternator down. The regulator does not tell the alternator to produce x-volts. The volts are the result, not the cause of charging system. If you read the description of the connection on the 614 there is only one connection that says "output" (i.e. cause) and that is the blue field wire. The regulator can only do one thing and that is to control how many watts the alternator produces.Hayden,
Continuing in my attempt at humor,
It's battery acceptance that at any given voltage will begin to resist the available current flow. This is critical in terms of understanding the process. For example, if you have a gigundous shorepower charger, let's say 200A, and a battery bank, regardless of size, that needs charging. Also regardless of SoC or % full or whatever you want to call it.
For ANY GIVEN VOLTAGE, there is a certain resistance of the battery to accept any more current, called battery acceptance. Because of the chemistry of the batteries were use on boats, the nominal optimal charging voltage has been determined across the industry, i.e., the guys that make these things, to be in the rage of 14+ V for a 12 V bank. This is to avoid boiling off the chemicals in the box.
All the regulator does is set this setpoint V. It does not "tell the alternator to reduce wattage" (actually what we measure as you know is amps). The battery "pushback" does that all on its own. An external regulator simply uses a built in time clock, much like any smart (not really) three stage charger, to change that setpoint after a certain time. External regulators simply check system voltage before they start the clock and do other cross checks, but that's immaterial to the basic concept of how the system works. Don't get caught up in the how until we can agree that you understand the what.
As the amps get pumped in and the bank fills, it pushes back more and more, as at the same time the system V is rising to the setpoint. This is what the graphs in Balmar's manuals and all charger manuals all show: time on the X axis, and V on the right, A on the left. If the setpoint V was lower the A flow would be less, thus taking longer to charge i.e., pump A into the bank, charge it. If the setpoint V was higher, more A would flow, the manufacturers recommend 14+ to stop killing the fluids and boiling them off. That simple.
Once the setpoint is reached, Amps reduce by battery pushback so even if the alternator was 600A, only how much the battery can accept at that particular SoC and V will flow. That's the only reason the A (watts) reduce. Nothing BUT the batteries is "telling" the charging source to do anything.
I leave it to Maine Sail to explain the how of regulators, but it seems to me that this basic understanding of how charging works is important, even if you get the answer you are reasonably requesting. I'll go re-read my Balmar manual again, too.
I use the term watts because it is the unit for "energy" and that is what an alternator produces and it is not dependent on voltage. Watts are the measurement of energy, volts the measure of potential and amps the flow of energy. (watts = volts x amps).
I will never understand why in the world of vehicular alternators the convention in the US is to list capacity in Amps. If you look any other form of energy producer, they are all properly listed in watts. A Honda EU200i generator produces 2000W, a solar panel or wind generator is rated in watts. To say that an alternator has a 100A rating, you must say at what voltage that is 100A @ 12v is the same energy as 85.7A at 14.0v.
We all know that if you turn your battery switch to "off" while the alternator is charging it will blow the diodes. Why does that happen? Because the alternator is happily producing a bunch of watts and suddenly the flow of electrons (amps) goes to 0. So in our 100A at 12v alternator, it is producing 1200 watts of energy. As you are closing the switch at the millisecond of time that only 1 amp is passing, what happens. 1200W / 1amp = 1200 volts (boom) The regulator did not set the volts to 1200. It did not have time to sense the increasing volts and turn down the field current / voltage so the spike in volts is the result, not the cause.
@Hayden Watson
Since our last discussion, I have looked for respectable, reliable and authoritative sources of information for you to consider, as well as to not let this thread end with misinformation.
"Ignorance, it’s said, isn’t what you don’t know, but what you think you know, that isn’t true."
This quote is from...
The Ample Power Primer
... which is a well respected guide to boat electrical systems and was written in the mid-90s.
The Start of the Absorption Step
At the instant battery voltage has risen to the maximum allowable
voltage of the charge source, current through the battery begins
to decline. This simultaneous event of reaching maximum voltage
and the start of current decline marks the beginning of the
absorption step.
For instance, if the 40 Amp charger is set to 14.4 Volts, then when
battery voltage has risen to 14.4 Volts, the charger will now hold
the voltage constant. Current through the battery will begin to
decline. NOTE: The charger, (or alternator), is not limiting the
current at this point. The battery is ‘absorbing’ all it can at the
voltage setpoint.
Nigel Calder's Boatowner's Mechanical and Electrical Manual, a trusted resource, discusses battery acceptance in great depth in Chapter 1. Figure 1-21 is titled Battery Charge Acceptance and provides an analogy to a water tank with baffles and semipermeable membranes. It is worth a read.
"When it comes time to charge...the rate of charge will be limited by the speed with which acid can filter out of the the active material, and water filter in, as the charging progresses. It is this diffusion rate that determines the charge acceptance of a battery..." p4, 2nd Edition
Finally, as Les said, regulators, whether internal or external, are VOLTAGE regulators, not wattage regulators or alternator starters or stoppers. They simply determine the voltage setpoint, which, once reached, as a pressure (voltage) limit, the battery acceptance determines the current flow from alternators and shorepower chargers alike.
Since our last discussion, I have looked for respectable, reliable and authoritative sources of information for you to consider, as well as to not let this thread end with misinformation.
"Ignorance, it’s said, isn’t what you don’t know, but what you think you know, that isn’t true."
This quote is from...
The Ample Power Primer
... which is a well respected guide to boat electrical systems and was written in the mid-90s.
The Start of the Absorption Step
At the instant battery voltage has risen to the maximum allowable
voltage of the charge source, current through the battery begins
to decline. This simultaneous event of reaching maximum voltage
and the start of current decline marks the beginning of the
absorption step.
For instance, if the 40 Amp charger is set to 14.4 Volts, then when
battery voltage has risen to 14.4 Volts, the charger will now hold
the voltage constant. Current through the battery will begin to
decline. NOTE: The charger, (or alternator), is not limiting the
current at this point. The battery is ‘absorbing’ all it can at the
voltage setpoint.
Nigel Calder's Boatowner's Mechanical and Electrical Manual, a trusted resource, discusses battery acceptance in great depth in Chapter 1. Figure 1-21 is titled Battery Charge Acceptance and provides an analogy to a water tank with baffles and semipermeable membranes. It is worth a read.
"When it comes time to charge...the rate of charge will be limited by the speed with which acid can filter out of the the active material, and water filter in, as the charging progresses. It is this diffusion rate that determines the charge acceptance of a battery..." p4, 2nd Edition
Finally, as Les said, regulators, whether internal or external, are VOLTAGE regulators, not wattage regulators or alternator starters or stoppers. They simply determine the voltage setpoint, which, once reached, as a pressure (voltage) limit, the battery acceptance determines the current flow from alternators and shorepower chargers alike.
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Stu, you might be surprised to find that I concur with 99% of every thing in your post. The disconnect is that I am looking at it from a "CAUSE" point of view and you are looking at it from the "EFFECT" point of view. Your POV is as an end user "tell me the result of setting voltage to 14.4v". My POV is from the regulator designer "What must the regulator do to maintain the voltage at 14.4v."
It is sort of like "does a spinnaker balloon out in front of the boat because the wind blows on it or is it because the increase in distance on the far side creates lower air pressure which PULLS the sail forward".
I have added <comments> below from the "CAUSE" pov.
It is sort of like "does a spinnaker balloon out in front of the boat because the wind blows on it or is it because the increase in distance on the far side creates lower air pressure which PULLS the sail forward".
I have added <comments> below from the "CAUSE" pov.
He's not backwards.. In order for the regulator to hold battery voltage to 14.4V it begins to pulse width modulate (PWM) the field wire once the constant voltage limit is met.. It is doing this based on voltage feedback from the sense wires. PWMing the field output wire controls how much current the alternator delivers to the battery. The regulator is controlling how much current the battery is fed by the alt so as to not over-shoot (or be lower for that matter) the 14.4V limit.... As SoC increases, and voltage is held steady, the pulse "width" of the OFF time grows longer and longer than the ON time...
I wrote about this quite a while ago below..
https://forums.sailboatowners.com/threads/musings-regarding-external-voltage-regulation.125392/
Ah, thanks, I now better understand Hayden's cause & effect, too. Amazing how "links" help, and refresh my (failing) memory.
I've been looking at it systemically, Hayden's point IMO has been field wire current and its effect.
My point has always been just what your link says:
3 - The alternator is not "forcing" or dictating amps to a battery, it does not do this, the battery "accepts" or lets current flow, based on voltage at the battery terminals and SoC.
4 -The alternator provides the current up to what it can provide or the battery can accept at XX.XX volts. Prior to the battery reaching the absorption voltage the alternator is basically *full throttle providing all the current it possibly can.
5 - A voltage regulator is little more than a VOLTAGE LIMITER. All it really does is LIMIT or maintain a preset voltage once the battery bank gets to the target voltage. External high performance regulators can limit voltage based on battery temp, alternator temp, time at voltage & other parameters but they still limit voltage.
6 - A typical voltage regulator has no clue what the amperage is coming our of the alternator. All the regulator knows is voltage, hence the term voltage regulator. Voltage regulators regulate based on voltage not amperage. While the amperage out of the alternator changes up & down to maintain a voltage set point the regulator is doing all of this all based on voltage.
7 - The internal resistance of a battery (SoC) determines the current it "accepts" or takes from the alternator to maintain a voltage at a specific state of charge.
All good.
I've been looking at it systemically, Hayden's point IMO has been field wire current and its effect.
My point has always been just what your link says:
3 - The alternator is not "forcing" or dictating amps to a battery, it does not do this, the battery "accepts" or lets current flow, based on voltage at the battery terminals and SoC.
4 -The alternator provides the current up to what it can provide or the battery can accept at XX.XX volts. Prior to the battery reaching the absorption voltage the alternator is basically *full throttle providing all the current it possibly can.
5 - A voltage regulator is little more than a VOLTAGE LIMITER. All it really does is LIMIT or maintain a preset voltage once the battery bank gets to the target voltage. External high performance regulators can limit voltage based on battery temp, alternator temp, time at voltage & other parameters but they still limit voltage.
6 - A typical voltage regulator has no clue what the amperage is coming our of the alternator. All the regulator knows is voltage, hence the term voltage regulator. Voltage regulators regulate based on voltage not amperage. While the amperage out of the alternator changes up & down to maintain a voltage set point the regulator is doing all of this all based on voltage.
7 - The internal resistance of a battery (SoC) determines the current it "accepts" or takes from the alternator to maintain a voltage at a specific state of charge.
All good.
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