Alternator smoking

[philippest]

Hi,

Since three years I have the same electric system (described below) which always performed nicely, but since I've had an engine fire half a year ago, the alternator starts smoking if I attempt to charge starter and service batteries. The fire was a result of the starter solenoid being stuck, hence sending a high constant current through the electronic engine control, which as a consequence started to melt/burn. We were required to change the starter, the wiring harness, alternator and electronic engine control.
Since then, I already fried a new alternator, so it would be nice if I could spare the current one from the same destiny.

If I disconnect the Service bat. the starter batteries are getting charged as normal. I've disconnect pretty much anything (inverter, heater, batt. charger, solar, wind, any domestic application....) from the service batteries to isolate the problem, but with no success. The only difference is the level of charge of the service batteries i.e. when they're fully charged the alternator can cope, otherwise not. I attached a schematic drawing of the original installation, the only difference today is the additional service batteries plus solar and wind charger (both connected to service batt only).

The battery banks are connected via a multi battery isolator to the alternator, with the sense wire connected to the serviceb. There's a 0.6-0.9V loss at the multilink, which is supposed to be normal. When charging all batteries I see about 13V at both battery banks and just below 14V at the alternator. If I disconnect the service batteries I get 15.1V at the Alternator and just above 14V at the starter battery.

Service batteries: 5 x 12V, 120Ah each/600Ah total
Starter bat: 12V
Bowthurster bat: 12V
Alternator: HC-cargo 115A (https://hc-cargo.co.uk/catalog/p/113971)

Solar charger (for service battery only) 400W
Wind charger (used to be for all batteries, but today only serviceb.) 40 - 290W,depending on wind

Thank you in advance for your input!

[smac999]

is the smoke coming from the belt? what size belt on your 100a alt?

how many amps are coming when it starts smoking?

sounds like it's fine with low load but not with high load. could be belt slipping or something inside is bad. mayb bad bbearings get hot with increased load ect.

it looks like the sense wire is on the house bank. I would not run the boat with the the house disconnected from the isolator as the alt will lose it's voltage sense.

if you moved that sense wire to the alt side the alt will charge less as then the alt will be ~14v and the batteries 13.2v you could try that and see if it still gets hot. not ideal for charging though.

once you get it sorted out I sugguest replacing that old isolator will a new low loss stye to give you better charging

[Jammer]

With a bank that large you may need an aftermarket regulator that folds back the alternator output based on alternator temperature.

[sailorboy1]

Originally Posted by philippest

Hi,

Since three years I have the same electric system (described below) which always performed nicely, but since I've had an engine fire half a year ago, the alternator starts smoking if I attempt to charge starter and service batteries.

Since then, I already fried a new alternator, so it would be nice if I could spare the current one from the same destiny.

Well you are over loading it and looking to start a fire much worst that the one caused by the starter! You need an external regulator and you need to adjust the belt manager on it so the alternator runs at a lower capacity.

[more]

Originally Posted by Jammer

With a bank that large you may need an aftermarket regulator that folds back the alternator output based on alternator temperature.

Marketing Mumbo Jumbo: Just because companies such as Balmar call "bulk" (BV) a voltage limited stage of charging, the simple answer is that this is not true

https://forums.sailboatowners.com/th...lation.125392/

#1
Lately there has been a lot of discussion around external vs. internal voltage regulation so I wanted to pass this info along. I had sent this to another member in an off line conversation a few weeks ago but tweaked it a little for a general posting.

If you want to avoid the diatribe below: In almost all cases an external regulator will yield a better performing charging system, but it may not make "financial sense" for your particular use.

The choice of external vs. internal should ideally be based on:

Your use of the boat
Your battery bank size
Your battery bank chemistry (Flooded, GEL, AGM, TPPL AGM, LiFePO4)
How much time you are willing to run the motor each day
DISCLAIMER: I usually try and stay away from this topic because many boaters don't fully understand how alternators, voltage regulators and batteries work and work together in concert. Once the money has been spent, they passionately believe their expensive system is working for them. Sadly about 85% or more of the alternator upgrades we see are incorrectly installed & set up. In many cases the system can be better than what they had, but with a proper installation, could be even better. Some owners however don't step back and make well educated decisions based on use and actual data points and can occasionally spend more money than they needed to. I will try to explain this subject as simply as I can.

I am making a LOT of general assumptions below so be patient:

1- Voltage is the pressure that cause the batteries to accept current.

2 - Amps are the "flow" and the higher the pressure/volts the more the flow/current can be.

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.

*Unless the regulator uses a temp gradient type regulator.

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.

Temperature compensation of the alternator and batteries is one of the most useful features of external smart regulators. Voltage limiting or voltage regulation modifies the alternators field voltage/current to maintain the desired set point voltage. This regulation technique is called pulse width modulation. Simply put the on time and off times are modulated at insane speeds in order to maintain the desired voltage set point the regulator wants to see or is limiting voltage to.

If the voltage starts to creep up the PWM or off time to the alternator field gets extended. Cutting back the alternators field limits the current the alternator can produce and thus a voltage limit is maintained and voltage over-shoot is prevented. Good quality external PWM regulators can control voltage to within a 10mV to 30mV range or 0.01V to 0.03V.

If you add a big load the regulator will boost the fields on time to maintain the voltage set point. PWM all happens so fast that you'd need an Oscilloscope to even begin to see it. If the load exceeds what the alternator can produce, eg: a bow thruster, the regulator reverts to full field or 100% output. Voltage limiting and PWM modulation of the field voltage/current go hand in hand.

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 determines the current it "accepts" or takes from the alternator to maintain a voltage at a specific state of charge.

With a small alternator, in bulk mode, the alternator will be limited to what it can physically produce, while hot. What it can produce is based on RPM and alternator winding temperature. Bulk just means "full field" or that the alternator voltage sense circuits has still not attained the pre-set voltage limit of the regulator. This stage of charging is called BULK or constant current (CC). In Europe, under DIN standards, they often call bulk charge a BOOST.

The relation ship of alternator current to banks size also plays a role. A small alternator attains the CV stage voltage limit at a higher SOC. Conversely, if you have a very large amperage alternator, the bulk period will be shorter and the battery bank will attain the voltage limit (CV stage) at a lower overall SOC. With a large source of current a battery can come up to absorption voltage more quickly because the battery can not accept the current, into the battery plates, as fast as the source can provide it. This builds a surface charge on the plates and results in driving the voltage up faster than a smaller current source.

8 - Let's address charging lingo such as *Bulk, *Absorption & Float.

FACT: Both smart and dumb regulators do both bulk (CC) and absorption (CV) or CC/constant current & CV/constant voltage stages.

BULK / CC - Bulk charging is essentially FULL FIELDING the alternator in both smart and dumb regulators. Bulk charging is any period of time before the regulator has attained it's absorption voltage limit at the battery terminal, or alternator, if "voltage sensed" there. In the bulk stage the alternator is delivering the maximum current it that it can based on temperature and rotor RPM.

As a battery charges during bulk its terminal voltage gradually rises. If the regulator, smart or dumb, has been set to 14.4v then until the batteries hit 14.4v is considered bulk charging. Bulk charging is also called constant current charging meaning the charge source, in this case an alternator, is supply all the current that it physically can at its current temperature and RPM.. Bulk is where the maximum current will flow into the battery because the batteries internal resistance is low due to being discharged.

During bulk charging the differential in pressure or voltage is at its greatest and thus the battery is accepting all the current the alternator can feed it as the terminal voltage slowly rises.

ABSORPTION / CV - Once the battery attains the voltage limit the regulator switches from the bulk/constant current stage to the absorption/constant voltage stage and begins regulating to the voltage limit.

Once the voltage is held steady or voltage limited the current being accepted by the battery begins to decrease. This is because the regulator is now operating in CV or constant voltage mode and as SOC rises the battery needs or accepts less and less current in order to maintain & not over shoot the voltage limit.


FLOAT/CV - Float voltage is a further reduced constant voltage limit applied by a smart regulator. Dumb regulators do not do a true float. If you feel you need float, because you motor a lot more than you sail, you's want a smart external regulator.

All of the above is based on what I have seen, read or heard most people misconstrue. You may not have misconstrued any of it but it is good to get out there.

[more]

Marketing Mumbo Jumbo: Just because companies such as Balmar call "bulk" (BV) a voltage limited stage of charging, the simple answer is that this is not true. Charge product manufacturers that do this, and we are a large Balmar dealer, are simply using incorrect terminology. Some companies do this purposely to confuse & confound the customer into thinking they are getting more. In teh case of Balmar the EE who designed the regulator used three CV stages and one CC stage. He called the first CV stage BV or Bulk Voltage, the second stage AV or Absorption Voltage and the third FV or Float Voltage. Seeing as Balmar was the first to have two absorption level voltages this seemed to make sense.

Of course, this is really all just marketing and we live with it every day. Bulk charging is constant current or when related to an alternator constant potential based on heat and rotor RPM. Bulk is simply not a constant voltage stage. In recent years more and more companies have begun using the incorrect terminology of "bulk voltage". You can have a bulk transition voltage, the point at which it transitions to absorption, but you can't really have bulk voltage that is constant voltage.

During bulk charging the battery voltage is ALWAYS on the RISE thus it can not be a "bulk constant voltage".. More appropriate terminology, as related to products such as the Balmar regulators might be Absorption 1 & Absorption 2.

As mentioned above I know why the designer of the Balmar regulators named it bulk voltage. I had long conversations with Michael, including discussions specifically about terminology, and he admitted it was an incorrect use of terminology that just got adopted by the marketing department. Of course, at the time, with a regulator that had 15,000 lines of code, correct industry accepted and defined terminology was far from the first thing on his mind.

Bulk = Constant Constant or Constant Potential Charging
Absorption = Constant Voltage Charging
Float and Equalization = Constant Voltage Charging
Charge Rate vs. SOC vs. Absorption Transition:
At the bulk to absorption transition voltage the regulator begins voltage & current PWM mode in order to maintain the pre-set voltage limit. With an adequately sized alternator this is often stated & repeated as a state of charge (SOC) of somewhere around 80% SOC. This however is not always a truism.

The SOC at which you attain absorption voltage is entirely dependent upon how much charging current you have. With a small solar array, you may not hit absorption voltage until 96% SOC and with a massive alternator you may hit absorption at 65% SOC. The point at which your battery bank attains the voltage limit is entirely depending upon how much current you have available. On top of current availability sulfation, battery state of health and *incorrect voltage sensing, among others, will change the point at which the battery attains the CV/voltage limit.

*Accurate voltage sensing is critically important on sailboats that desire short engine run times. Factory alternators do a horrible job with this. For more in-depth discussion on this subject see: Alternators and Voltage Sensing Why It's Important

Sulfation & SOH Impact Bulk Charge Time:

A sulfated battery or a battery in poor state of health (SOH)will quickly rise to absorption voltage despite not yet actually being charged. Simply put until a battery reaches the voltage limiting set point, absorption charging, all regulators, smart or dumb, simply "*full field" the alternator to what ever the regulator can produce in field voltage/ field current. Battery chargers and solar controllers operate the same way.

If your battery bank starts out at 50% SOC and you;re attaining the voltage limit in a short period of time the battery is likely shot. At a charge rate of .2C, or 20% of Ah capacity in charge current, it should take an hour or more to attain the absorption voltage limit.

*The exception is an alternator with a thermistor/temp gradient regulator.

Can Internal "Dumb" Regulators Really Do Bulk Charging?

Yes they absolutely can, though there are certain things that can impact just how well they do this compared to an external regulator.

The question below was posed on an external alternator regulator manufacturers web site. This company builds smart external regulators and alternators.

Question:
As I understand it most of the regulators regulate voltage not amperage? Before the regulator hits the absorption set point, mine is 14.4 volts, they are simply full fielding the alternator. So do both dumb and smart regulators do the same to the alternator, apply full field until the absorption voltage is reached?

Answer from Manufacturer:
You're correct, during the bulk phase, the alternator is 'full fielded', by all regulators. But the term 'full fielded' is loosely defined as applying the maximum voltage that can be applied by the regulator. If you measure the voltage drop between B+ and field during the bulk cycle you'll find that an XXXXX Regulator drops the least voltage of any regulator. More voltage on the field means more Amps.

While the external regulator can produce a higher field potential, is this always necessary? The answer is no, it is not always necessary. We should consider that an external regulator must be able to drive any alternator it is fitted to, and it will need the capability to deliver a wider range of field potential to any alternator out there. External regulators can deliver upwards of 15A to drive the field. An internal "dumb regulator" only needs to produce enough field potential to drive the specific alternator it was designed to be fitted on in order to attain its maximum output rating. For some alternators this may require as little as 4A. There is no reason for Delco, Bosch, Paris Rhone, Leece-Neville etc. to design an internal regulator capable of 15A when the alternator is only needing 4A to attain its full output. In industry pennies count. A general fit external regulator must be able to drive any alternator so they are built to do this. While the statement above is technically true it is misleading at best.

A few years ago I spent an entire Saturday at a friends shop conducting experiments with many different internal dumb regulated alternators. This shop has a $30,000.00 alternator testing machine I got to play with for hours.. I loaded random internally regulated alternators into the machine and tested them for max alternator rated output.

Bottom Line? Every single internal dumb regulator applied enough field voltage/current to achieve the max rated output of the alternator, every one. Keep in mind however this was "cold testing" and as some alternators heat up they reduce the voltage limit based on internal thermistors. I will get to this later.

While you may be able to apply more field potential, as most external regulators have the ability to, you can't exceed the alternators physical capabilities. If the alternator can hit its maximum output rating with a *dumb regulator, then a smart one, set to the same voltage and sensed at the same spot, will not increase charging times in bulk stage.

*Excludes thermistor equipped/temp gradient internal regulators

This video may help pull some of the above together:
https://youtu.be/GC1jIKpC7Zw

reed more https://forums.sailboatowners.com/th...ion.125392/ore