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GS Stator

Jim, my Kawasaki manual states "maximum alternator output" at 238 watts.

If as you say, and I believe you, the vehicles consumption is 203-217.5 watts, that leaves roughly 20-40 watts extra to be returned to the stator.

These charging systems are permanent magnet, so as I understand it they will produce the power whether the bike needs it or not.

It's certainly possible that a Suzuki GS stator makes more than 240 watts, but I don't think it's more than 270 watts or so.

You apparently do not believe me. They are only specifying total delivered to the load. It is also very easy to measure this as I have done.

This does not include heat losses in the R/R or the stator.
 
Eating popcorn and watching here, always up to learning new stuff!
 
Tom how did you convert current into watts?
I took an overly simple approach.. As usual

In balanced 3 phase power.......P=1.73VI
where I is the measured leg AC current and V is the Dc voltage of the r/r output.
with the shunt unit I=11amp... with the series I=6.8 amp
V was 14.2 volts in both tests.
 
I took an overly simple approach.. As usual

In balanced 3 phase power.......P=1.73VI
where I is the measured leg AC current and V is the Dc voltage of the r/r output.
with the shunt unit I=11amp... with the series I=6.8 amp
V was 14.2 volts in both tests.

Unfortunately you are mixing stator current with DC output voltage.
We know for a Series R/R that the average stator current is going to be proportional to the DC output current whereas that relationship is more complementary shunt (rising DC current decreases stator current).

To turn this current into power you either need the stator resistance or the stator leg to neutral voltage.
 
You apparently do not believe me. They are only specifying total delivered to the load. It is also very easy to measure this as I have done.

This does not include heat losses in the R/R or the stator.

I believe you measured power...and your bike had one of those high powered stators too...which burned to a crisp.
 
I believe you measured power...and your bike had one of those high powered stators too...which burned to a crisp.

You can believe this as well.
I should add for total redundancy that the 14-15 amps I quoting is not a constant. It is a nominally charged battery with bike at approximately 3500 RPM headlamp, tail lights BUT with blinkers and brakes OFF without other accessories.


Stator_power_zpsynxhlp1e.png


Ed you make it very laborious having to repeat the same information over an over again. I would have thought you would have remembered by now that the total maximum output of a stator can not be changed by rewinding it short of not winding it. It is completely determined by the rotor which I did not change.
 
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If anyone needs another stator, I strongly suggest contacting Tim Parrot... http://tpe-usa.com/

...you get a higher output, etc....and his prices are great....a LOT better than some of those offered on Ebay, btw....this guy knows his stuff....
 
The higher the stator output, the more you need a series r/r. Member Steve also has a rewinding guy.
 
quote_icon.png
Originally Posted by Gorminrider

and then there's a few oddities that make me wonder:
if you goto the link offered in post 31 http://www.thegsresources.com/_forum...97#post2130797 and look at the pictures of the Stator heat, you will note a discrepancy in the colour scale. The white Hot of the series colour scale picture is 174C while the upper whitehot of the original shunt is 150. This means the series will appear somewhat cooler, I think.

3) isn't this Aprilia in the above example (an Aprilia) water cooled? a detail per "stator heating" might be how long the bike was running before each heat-picture was taken.

I think that was the point of the pictures.

So do I, and that's what worries me. the 'original" appears to be hotter due to the "white hot" being 150c versus the new regulator with 'white hot' being 174c. It occurs to me both pictures would be more similar using the same scale. I'm not impugning the author but when I test things, it's always pleasing to get the results I am looking for, if you know what I mean...:)

File: IR Lima cover original Spannungsregler.jpg





File: IR Lima cover Compu-fire.jpg


 
Please allow me to interpret the graphs........................


In German, Messpunkt means "measuring point". You will note that in the upper lefthand corner the original is 114 degC and the Compufire is 97.7 degC. That is a 16.3 degC differential. In something more familiar to us not use to Celsius, 117degC converts to 242.6degF and 97.7 converts to 207.9 degF. That is a 34.7 degF differential.


From looking at the image and the reticle centered on the stator (as well as the high resolution of the image) I think it is safe to say that the Messpunkt, is an average in the near region of the center retical. This does not imply that the engine oil will be 34.7 degrees cooler using the Compufire, but that the stator is running substantially hotter with the shunt R/R.

The fact that the image temp autoscaled does not preclude a comparison of the images, but in fact none is nessesary as the Messpunkt reading tells you the absolute differential at the stator cover center.
 
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Stock stator was 180W, high powered aftermarket stator was 300W. No wonder the aftermarket stators fry out.

There is more to those numbers than what Electrosport is marketing them as. The maximum current is always limited by the rotor. You can't change the stator and get more peak current. I would say the chart is an outright lie but I can not detect the caveats being applied to the data where it might be not so blatant.

The much heralded 20% increase power that Electrosport claims on their stators is only at RPM's below peak current.


In simple terms the motor is making ever more power available to the charging system with increased RPM. In fact the power available is going up as the square of the velocity (i.e. RPM). So why does it flat line? What happens to the "conversion efficiency". The answer is that the rotor magnets can only support so much current. Once you get to that peak no matter how fast you spin the rotor you only get out so much current.

So any two stators will both hit the same peak current. Depending upon how they are wound the only differential will be in at what RPM that occurs. The high output stator will do it at a lower RPM.
 
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On the other hand, purchasing a shunting R/R borders on lunacy in this day and age since series R/R's are readily available and cheap. May as well.

nessism, I have 3 suzukis, 1 Honda . I guess it depends what you consider to be "cheap". Tires come first. All have shunt r/r's. All work fine. 3 get considerable use-200km rides are common for any of them in the summer and for the Honda, 2000 km on occasion.....only the Honda has its original stator and the original shunt R/R
I have replaced all 3 Suzuki stators and only one of these has its original R/R ( a 650 that has not yet been broken in) One even has a $22 ebay generic shunt RR that seems to be hanging in there....

I think where people get into big trouble with cooked stators is when using one of those "heavy duty" type stators (like an Electrosport) that produce more power than stock and too much power for a normal GS to consume, thus the stator winds up cooking itself.

Nessism, this is an interesting point ..... When people are busy converting to LEDs on one hand and then going for Heavy Duty-Hi-Output stators on the other hand, they are making some kind of mistake, unless they are running other hi loads as well- a heated vest and gloves maybe.
It even got me to think of the much unloved "stator loop". Imagine if a stator leg WAS dropped when output overmatched the loads. Or when an led'd bike was not needing the rider's heated vest....Perhaps using a relay versus the original long-wire to a headlight switch....
 
Nessism, this is an interesting point ..... When people are busy converting to LEDs on one hand and then going for Heavy Duty-Hi-Output stators on the other hand, they are making some kind of mistake, unless they are running other hi loads as well- a heated vest and gloves maybe.
It even got me to think of the much unloved "stator loop". Imagine if a stator leg WAS dropped when output overmatched the loads. Or when an led'd bike was not needing the rider's heated vest....Perhaps using a relay versus the original long-wire to a headlight switch....

You are absolutely correct on both points. In fact there are several posts and discussion warning about LED modifications without changing to a SERIES R/R else your SHUNT R/R will overload the stator and burn it out.

As far as matching output to load you are also absolutely correct, Suzuki started doing this 40 years ago except unfortunately the accumulated environmental exposure was too much for the connector and switches to endure. I'm sure a modern stator leg loop relay modification could be developed but you better look for a high voltage relay; probably Solid state to stay in this century.

Of course anybody looking to just solve the problems and move on would simply just install a SERIES R/R and all these revelations, and workarounds would become mute.
 
Electrosport has this little blurb on their website where they mention how dropping out one leg of the stator cause "imbalance" in the system. Might be more BS, not sure, I'm not sure what the real world effect this has either. I do know I'm not a fan of high output stators though. I'm no expert on the subject but I do know that the number of turns and the size of the wire influences output when winding stators. The strength of the magnets is also a factor in how much current is generated and at what rpm. I think that Kawasaki's KZ bikes have lower output charging systems than Suzuki GS's, and they don't seem to have as many failures. Less output current flowing through the stator causing insulation breakdown for one, and less shunted current going back for another. Sort of counter intuitive to improve the system by downgrading the output but that's the reality.
 
Electrosport has this little blurb on their website where they mention how dropping out one leg of the stator cause "imbalance" in the system. Might be more BS, not sure, I'm not sure what the real world effect this has either.

The imbalance is in the 3 phase stator output (all three phases are not identical).

A three phase power source applied to a full wave rectifier generates DC with something on the order of 5% or less distortion (residual AC in the output). I don't recall the exact number but it is in this range . When you create imbalance in the phases, then the residual AC increases. On a GS the AC is in the audible range and varies with RPM.

On my GS750 which idled quietly it was actually audible when the leg was switched in and out and would lower the idle slightly. It was obviously as well looking at the AC using a scope. Other than creating more ground bounce (i.e. noise) it is not really an issue as pertains to "imbalance".

You can get an idea about what this means from looking a this chart. It shows the residual AC from ideal rectification. If the three legs are different it just gets more AC at the output. You can use higher number of phases and teh conversion gets better but as you can see more complicated. 3 Phase is popular because of this low distortion with only 3 phases at 120 degrees relative phase difference.

https://en.wikipedia.org/wiki/Rectifier#/media/File:3_phase_rectification_2.svg
Rectifier


https://en.wikipedia.org/wiki/Rectifier
 
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I went thru 3 Electrosport stators in one season.....they made good on all, but the swapping really wasnt worth the few bucks you save, IMO....Ive had the TP in 2 different engines now, with no issues....

These Ebay distributors....a buddy of mine haz a KZ1000 (Concourse)....he insists on buying the junk from Ebay, like the Electrosport stuff, spends a week installing, rides for a month, and stuff is shot......I cant understand why some dont "get" that sometimes you need to pay a lil more for quality. Research the manufacturers before you buy. And ya, sometimes ya pay more.....but at least it will LAST....

Theres another guy on Ebay who sells bike electrics....cant remember the name...but thats another loser....oh yeah..."Rick's"...
 
I went thru 3 Electrosport stators in one season.....they made good on all, but the swapping really wasnt worth the few bucks you save, IMO....Ive had the TP in 2 different engines now, with no issues....

These Ebay distributors....a buddy of mine haz a KZ1000 (Concourse)....he insists on buying the junk from Ebay, like the Electrosport stuff, spends a week installing, rides for a month, and stuff is shot......I cant understand why some dont "get" that sometimes you need to pay a lil more for quality. Research the manufacturers before you buy. And ya, sometimes ya pay more.....but at least it will LAST....

Theres another guy on Ebay who sells bike electrics....cant remember the name...but thats another loser....oh yeah..."Rick's"...

I prefer Electrosport and with a Series R/R they are no problems. The GS1100E stators have been high quality like this one. Heavy epoxy to immobilize the winding. Most people probably do not realize that the are Electromotive forces on the winding which will cause flexure if not supported. A thermal epoxy as you see here is what is used. It is not just for insulation, it is to keep the winding from flexing under the EMF forces. If you see winding that do not appear to have anything but a thin insulation cover, they are going to be less tolerant to usage.


I don't know that all of Electrosport product coating are this heavy but there are superior to most I have seen from any other vendor. If you are still using Shunt R/Rs and burning stators well there is not much anybody can say to help...............

This picture was to document heat damage from a MOSFET Shunt R/R after a 250 mile ride on a brand new ES stator. It was getting hot.

attachment.php
 
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I'll take a Rick's stator over most others. Less reported issues in my experience. They are more expensive though.
 
I went thru 3 Electrosport stators in one season.....they made good on all, but the swapping really wasnt worth the few bucks you save, IMO....Ive had the TP in 2 different engines now, with no issues....

These Ebay distributors....a buddy of mine haz a KZ1000 (Concourse)....he insists on buying the junk from Ebay, like the Electrosport stuff, spends a week installing, rides for a month, and stuff is shot......I cant understand why some dont "get" that sometimes you need to pay a lil more for quality. Research the manufacturers before you buy. And ya, sometimes ya pay more.....but at least it will LAST....

Theres another guy on Ebay who sells bike electrics....cant remember the name...but thats another loser....oh yeah..."Rick's"...
It's stories like yours or maybe yours that convinced me to follow posplayer and convert to a Series R/R. Electrosport sells Shunt R/R's and that or any other Shunt R/R and electrical system condition is the culprit, not the stator in the majority of cases. In this you do not know what you are talking about. Electrosport actually makes good stators along with Ricks and many of our members have had real good luck with Ebay stators. I have only heard of a couple of cases on an 1150 I believe where an Electrosport stator failed that had been fitted with a Series R/R and that was a fit problem with the stator where some wires were out of place and got pinched in installation. You are complaining about the result of having used Shunt R/R's not crappy stators. It's not your fault because that is the majority of R/R's on the market and you wouldn't have known, but now you are in a place that knows better and you can correct that problem and incorrect statements with the information posplayr has brought to everyone's attention. I'm talking about bikes with three phase AC generators like the GS so anything with another system I can not answer for and is not within my experience. Posplayer's picture below of a failing Electrosport stator is exactly the results of using shunt R/R's no matter what the quality of the unit and not the stator at all.
 
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