Another alternator hits the dust and not under warranty

Discussion in 'Parallel Universe' started by C5!, Jul 11, 2011.

  1. Hicks

    Hicks der Überluber

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    it looks good! -- that one for ST is different from ours?

    Mine having a second alternator + regulator... I'm expecting another alt. failure :(
  2. Cesar Serpa

    Cesar Serpa Adventurer

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  3. JoelWisman

    JoelWisman Long timer

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    I haven't finished testing a solution for the F8 early stator toast issue, but, have identified the problem.

    Virtually zero oil splash and magnetic saturation that is a little too high to keep the stator cool enough for longevity with anything short of exotic magnet wire insulation.

    I posted some info in this post, http://www.advrider.com/forums/showpost.php?p=18262767&postcount=34

    And there is a little more buried in that same battery thread, but this is a better place to post about it as that is a genuine battery thread started by none other then myself lol.

    The skinny is that BMWs oem stator is already using absolute top of the line 200c insulation for the stator and it is still failing early because the stator is simply running too hot.

    Most quality rewinders use magnet wire with 180c insulation which is still considered very good insulation, but in the F8 that is way too low which causes very early failure.

    Barring someone using a glass sleeve, an expensive and difficult proposition I can't think of what to do besides inserting external resistance which will slightly de-rate the alternator output.

    I have a test setup running on a few bikes, but while the fix is vetted, I would keep the aftermarket leeds on that stator full length as that will increase the external resistance at least slightly.

    Also a voltage regulator with a higher charging voltage in the 14.3 - 14.5 volt region will help, as would a series voltage regulator, a LOT, as long as the rest of the bike can tolerate noisy regulation.

    Good luck.
  4. Indy Unlimited

    Indy Unlimited Long timer

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    I might design an external cooling fin and drill the case and conduct the heat outside the.bike. Thanks for your research Joel !
  5. ebrabaek

    ebrabaek Long timer

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    Next mod .... liquid nitrogen stator injection system......:lol3

    :thumb:thumb

    Erling
  6. JRWooden

    JRWooden Long timer

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    Indy ... I thought about that also ...
    Side cover is pretty thin metal, but I'll bet there'd be a way...
    I remember back in the really old days they sold finned side covers for the Honda 750s :wink:


    IIRC there did not seem to be a lot of contact area between the stock stator and the side cover either which isn't helping...

    Also, a modification that would dribble a small stream oil into the stator area might help... but I think we came up blank on where to source the oil from without risking something important....
    Pity ....

    I wonder if there is some heat pipe arrangement that we could stick in the open center of the stator and conduct heat away without making too big of a hole in the side cover?

    At the very least we should all likely get the SH541-SC R/R .... I wonder if we could do a group buy on that puppy?
    I'm not sure where we could source it from, but I would think that with a decent sized group we could get the cost so something less than $100... ???
  7. MTrider16

    MTrider16 Ridin' in MT

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    Joel thanks for posting a summary here. I will be keeping an eye on mine.

    Why does higher regulator voltage help out? Our company control guys think 13.8 is a high voltage for a lead acid battery for thier backup DC systems.

    Regards,
    David
  8. JoelWisman

    JoelWisman Long timer

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    De-rating is simple, but of course you will loose some power to run accessories.

    The stator runs much hotter then any surface of the case cover, so a thermally conductive potting compound between the stator and cover would help quite a bit I would think, as would a radiator (heat sink) if you could get good transfer to it.

    A nozzle to flow oil over the stator would work awesome, and there are oil ways that could be tapped in the area. The question is: Can components downstream survive the loss of oil pressure? I sure wouldn't want to be the one to find out!

    Note: IR guns are useless for measuring temperatures, especially on surfaces with varied emissivity such as these.

    Once I am done using it on my battery test project, Indy or anyone else is welcome to barrow my 4 channel thermocouple.

    It is handy because you can measure 4 places at once, min/max/average. It is what I used to measure stator temperatures but could be used to measure stator, cover, heat sink, or whatever.

    Average temperature needs to be below 160c for the stator to last the life of the engine. It currently runs 180-200c

    As to the voltage regulator, yes one with a higher voltage clamping level will help, though how much is beyond my skill set to determine without simply trying it.

    I have the new oe SC regulator, but was leaning towards selling it as I need the money lol.

    FET is better then SCR. a sensing wire is very nice. external leeds good. look up any modern bike with a 400 watt or larger charging system. BMW is probably the only manufacture that got this part wrong in modern times
  9. JoelWisman

    JoelWisman Long timer

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  10. Gangplank

    Gangplank Advenchaintourer

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    So am I reading this correctly that stators are failing upwards of 50,000 miles?

    Also does running an after market cooler regulator/rectifier help cool the stator? If so that seems like a fairly easy solution.

    And what farkels and/or what battety are people running on the bikes that fail? Surely they aren't running the stock batter with that kind of mileage.
  11. JRWooden

    JRWooden Long timer

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    I'm starting to get a tad depressed...

    My warranty has expired.
    * I'm on my second gas tank and it is cracking (likely I'll get this replaced under the 2-year parts warranty later on),
    * even though I've run nothing but regular H7 55W bulbs, my headlight reflector will be shot soon - the metalization is
    crap and the reflector not being available separately means $450 out of pocket unless I can get some goodwill
    somehow...
    * and we've got this regulator issue....

    :cry

    Ok ok ... no more crying in my beer for now...

    Joel: Seriously, thanks for your help - not having much regulator design knowledge: is the FH012AA still a shunt type design, or is injecting noise on the CAN-BUS a worry, or does FET design sidestep the whole shunt/series problem? :huh

    It sure would be nice to have thermocouple runs to compare the "standard" setup to the "SC" to the MOSFET
    I'll chip in a 5th of libation to anyone that could take on that job, I'll bet a few other guys that are subscribed to this thread would do likewise if someone could assemble all the stuff in one place ...

    Hey I got another idea:
    we can re-route the coolant lines that go down to the oil cooler to run past the stator :lol3
    < he says ... only half in jest >
  12. JRWooden

    JRWooden Long timer

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    I'm no expert but I'll take a stab:

    Yeah... the regulator design is such that regardless of the actual "demand" for power from the bike, the stator runs at full load all of the time. The stator is inside the flywheel and has no oil splash or other cooling and as a combinded result it gets too hot - up to or exceeding the temperature rating of the stator wiring and fails ... it seems to happen in the 40K - 60k miles area....

    The OEM regulator is a "shunt" design and runs the stator flat-out. Some regulator designs "series" style do NOT run the stator flat-out, and thus it would not get as hot, there is concern that the series style might inject electrical noise into the system and screw up the CAN-bus... I don't think we know how valid this concern might be....

    I don't think the battery is specifically part of this issue, but there is a related issue in that the regulator that is installed on most bikes the - SH541-12 is set to a lower voltage (13.x volts) than some of the alternative chemistry batteries desire - e.g. the Shorai. A different model regulator seems to be showing up in the parts channel and on newer bikes - SH541-SC which regulates at a higher voltage. This helps with the stator cooking problem but we don't know how MUCH it helps... it is also helpful to folks that want to run an alternative chemistry battery ...

    ok time for more coffee...
  13. vtbob

    vtbob wanderer

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    There is not much we can do about the low cost/low weight shut electrical system. Putting a field regulated alternator is a major mod...both to the stator/rotor (not sure the on alternator electronics/rectifiers would survive in current location) and of course a totally different regulator.

    Re higher charge voltage to alternate technology batteries. This too is likely not as simple as it sounds...especially for Lithium based batteries. there are several Lithium chemistries...managing the charging voltage is not consistent across lithium aternatives....and if not improperly managed/charged, lithium batteries can self destruct. For this reason, I do not think you will see either auto or motorcycle manufactures offering "lithium" compatible charging systems....mainly because the lithium technology has not settled down to a common charging, discharging, maintenance set of parameters.

    The lithium battery manufacture put "stuff" in their batteries to attempt to manage this....It does not seem they have really gotten a reliable handle on that part either. i.e. the bleeding edge of technology
  14. JRWooden

    JRWooden Long timer

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    I agree, my point here was that even by AGM battery standards, the twin's R/R puts out substandard voltage.
  15. 'Flagger

    'Flagger ..this space for rent..

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    I searched .... and failed.

    Can someone point me to the post ... I think by Joel ... that describes how to test or monitor a stator for pending failure?
  16. JRWooden

    JRWooden Long timer

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    Simple tests would be:

    Disconnect 3-wire plug from Regulator to stator.

    Test resistance from pin 1-2, 2-3, 3-1 (this measures the resistance of the 3 phases of the stator)
    All three readings should be low and approximately equal.
    If any of these three readings are high or infinite you have burned out (open) windings

    Test from any of the leads to chassis ground the reading should be very high or infinite (10M-ohms or better)
    If the reading is low your stator has shorted to ground ...

    Joel had another test ... that actually did a quick test of each phase's output....
    I *THINK* he took a piece of small gauge wire (24g ?) and shorted each of the phases (1-2, 2-3, 3-1) with the bike running... A good stator winding will "smoke" the wire :evil
    Do this one at your own risk... :lol3

    Fail any of these tests and I think you need a new stator, but they may not warn of impending failure....
    Monitoring these values over time and checking resistance to ground with a "megger" might give advance warning...
  17. Cesar Serpa

    Cesar Serpa Adventurer

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  18. 'Flagger

    'Flagger ..this space for rent..

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  19. 'Flagger

    'Flagger ..this space for rent..

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    Tests 1 and 2 will done before dinner. Test 3 ... maybe not. :lol3

    Thanx!
  20. JoelWisman

    JoelWisman Long timer

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    I am told by a person that would know that the failure rate of the stators exceeds 50% by 50,000 miles. Many fail earlier and many fail later.

    This is on stock bikes but extra load doesn't matter unless your load actually exceeds stator output and drives the voltage down, which is not going to be common as under those conditions your battery would also run dead as you rode.

    All motorcycles that have permanent magnet internal alternators use shunt style regulators that simply ground out the excess capacity of the stator. In effect, they use up any excess capacity the charging system has to keep voltage at their set point.

    Most F8s use a regulator that shunts voltage at a lower voltage then is ideal for AGM or LiFePO4 battery charging. This is not a defect as the bike continues to work with the usual oe regulator and none are going to get changed under warranty unless they actually break.

    To an unknown degree, installing a regulator that shunts at a higher voltage will in addition to making AGM and some LiFePO4 batteries last longer, will allow the stator to run at least slightly cooler because the stator will produce slightly less current at the higher voltages of 14.2 - 14.5 volts, then it does at 13.84 which is what most F8 stock regulators are set for.

    The stator is also not defective unless it fails during warranty, it just sucks from a longevity / reliability standpoint because the totality of design runs it at the raggedy edge of heat it can tolerate and as such it ages quickly and tends to fail early which is not ideal but not THAT uncommon on motorcycles.

    A shunt style regulator is the opposite of a series style regulator. I am not aware of a single bike that has ever come oe with a series regulator and there are reasons for that.

    1: series style regulators cost more

    2: series regulators are bigger and weigh more

    3: series regulators of the past have been electrically noisy and caused interference with other systems such as fuel injection and ABS computers.

    4: series regulators cause high voltages in the stator which along with something called "ring" can damage stator insulation of stators and age them as fast or faster then the heat load from shunt style regulators.


    The benefit of series regulators are:

    1: unless you are using 100% of stator capacity, the stator will run cooler.

    2: the bike will get better fuel economy because the stator isn't sucking as much horse power from the engine when you aren't using the full output from the stator


    Recently, series regulators came onto the market with advertisements that they had technologically solved all of the previous negatives.

    I don't know if this is true, but could tell likedysplit if someone bought one and rolled by my place with it installed. It could be advertising BS or it could be the truth in which case series regulators are the way to go.

    The link I provided ( http://www.ebay.com/itm/UNIVERSAL-M...ies&vxp=mtr&hash=item588e7e9386#ht_1428wt_781 )

    Is for a quality mosfet shunt style regulator with a nice kit. The guy selling it is NOT me and I don't know him from Adam, but he is also in Missouri, which I like, and is in Joplin which got mowed down by a tornado last year so could probably use the business.

    It is a 6 wire regulator. 3 for stator, 2 for connection to the stock B+ and B- wires, and an extra wire called remote sense. You run one additional wire from the regulators remote sense direct to the positive battery terminal. this wire carries no load so is not confused by voltage drop or ring into lowering the high rpm voltage like the F8 oe regulator does.