Increasing Stator Output - Rewinding Stator.

[bmccrary]

Ok so with this senior design project I am putting to standard lights on the trailer. However these added lights will possibly put me over the max stator output, so I had to do some calculations...

We all know the stator has 310watts, and the bike pulls 240w. This leaves 70w.

Add the dual head light mod, and depending on the power of your H4 bulb, there goes a good chunk of power. Add a high wattage high beam like 100/55w I have and your screwed... In addition, a intercom/CB system and I am not sure how my bike is even charging.

I found a company called Custom Rewind out of Birmingham Alabama that has agreed to rewind my stator. This company is well known in the Gold Wing community as they are usually able to rewind a stator and increase its output over the factory numbers. After playing phone tag with the owner, Gary, he said that he had never rewound a FZ6 stator and wasn't sure how much more juice he could get out of it, but felt fairly certain he could get something.

I pulled the stator off earlier this week and shipped it to him on Thursday. He told me he would get this done ASAP and have it back with some numbers recorded.

As usual I will be sure to post the results when I find them out and I will ask him what the going rate will be for this service. I am sure many of you will be interested in having this done if the results are positive.

-bryan

 

[dean owens]

depending on price i could be pretty interested in this. i'd also be very interested to know if a larger stator from another bike (say an fz1) would be able to fit or not).

 

[RJ2112]

This is the first time I have heard of someone taking the time to develop a modification that may increase the alternator output.

Not being an alternator guy, I understand them in a loose theoretical sense, and know what the difference between a generator and an alternator are. As the alternator spins the electric field, which induces the current in the windings of the stator..... can the field strength be increased, to generate more current as well? I would expect the FZ6 to have a 3 phase alternator..... that's pretty much the standard; can you get the alternator shop to confirm that when they do your rewind?

Hitch hiking on Dean's question, can you also have them get the physical dimensions of your stator ring, before and after the rewind?

 

[simonwb]

As usual I will be sure to post the results when I find them out and I will ask him what the going rate will be for this service. I am sure many of you will be interested in having this done if the results are positive.

-bryan

Yes, please and I guess we'll be able to find someone to do something similar this side of the Atlantic.

 

[bmccrary]

From my understanding he will be rewinding the stator and adding more windings from the stock size. In our bikes, the stator remains stationary while some sort of hub spins around the stator. Stator cover can be easily removed, just be ready to catch a little oil when this is pulled off. There is a strong magnetic field on this, so it will take some force to get it off. In addtion there is a small spur gear that connects the starter motor to the flywheel an dthe pin it rides on is held in place by a boss in the stator cover, so watch for that.

You could cross reference the part numbers on the stator between the Fz6 and Fz1... that might start answering some questions.

-bryan

 

[Cali rider]

It is my opinion that rewinding the armature will not increase output as the voltage regulator/rectifier is the choke point. The test I ran a few years ago demonstrated that the 3-phase voltage from the alternator continued to rise with RPM but the peak DC output from the R/R module hit a maximum output of 14.4 volts/22 amps somewhere around 2200 RPM regardless of load applied.

If I was going to attempt to increase the electrical system power output, I would acquire a R/R from an FJR 1300, which I beleive is rated @ 490 watts. Plug it in to the harness (or modify as needed) and take some readings of power available with a substantial load.

I'm not being negative with the preceding comments, just hoping to add another point of view. If rewinding works, I will be the FIRST to admit my error in analysis.

 

[bmccrary]

It is my opinion that rewinding the armature will not increase output as the voltage regulator/rectifier is the choke point. The test I ran a few years ago demonstrated that the 3-phase voltage from the alternator continued to rise with RPM but the peak DC output from the R/R module hit a maximum output of 14.4 volts/22 amps somewhere around 2200 RPM regardless of load applied.

If I was going to attempt to increase the electrical system power output, I would acquire a R/R from an FJR 1300, which I beleive is rated @ 490 watts. Plug it in to the harness (or modify as needed) and take some readings of power available with a substantial load.

I'm not being negative with the preceding comments, just hoping to add another point of view. If rewinding works, I will be the FIRST to admit my error in analysis.

Thank you for your input. The reason I headed down this road was due to my off road experience. When adding lights to a MX bike the first thing to do is to increase the output of the stator, which in most cases is just a replacement. I will look into the R/R from a FJR as there will be one next to the FZ in the basement when I get home. :innocent: might have to "borrow" it from dads bike...lol.

-bryan

 

[RJ2112]

It is my opinion that rewinding the armature will not increase output as the voltage regulator/rectifier is the choke point. The test I ran a few years ago demonstrated that the 3-phase voltage from the alternator continued to rise with RPM but the peak DC output from the R/R module hit a maximum output of 14.4 volts/22 amps somewhere around 2200 RPM regardless of load applied.

If I was going to attempt to increase the electrical system power output, I would acquire a R/R from an FJR 1300, which I beleive is rated @ 490 watts. Plug it in to the harness (or modify as needed) and take some readings of power available with a substantial load.

I'm not being negative with the preceding comments, just hoping to add another point of view. If rewinding works, I will be the FIRST to admit my error in analysis.

I had the time to put my Fluke model 87 accross my battery, via the quick disconnect for my Widder vest, and monitored the voltage at that point in a number of scenarios..... looking to see what the available output was and where it 'peaked'.

I'm sure this is 'old ground'; I don't know that I would agree that the peak output occurs at 2200 RPM.

My testing was pretty straight forward, I monitored for the regulation of the output of the alternator/regulator, and increased RPM until I got back to 14.2 volts, under various loads.

With the OEM lo beam (single H7 lit) I could maintain 14 volts and change at idle.

Adding the second lo beam element from the H4, it took more than 1500 RPM to maintain that regulated voltage... output from the alternator was not providing enough current to need regulation at idle any more. I'm going to have to dig out the spread sheet I built for that.

With the H4 on Hi, and the H7 lit, it took more than 2K RPM to maintain the regulation..... as I recall , it was much closer to 5K on the tach to get back to where the system was producing a 'hard' 14 VDC........ this would indicate to me that the alternator was continuing to produce more current with RPM; at least up through 5K.

I suspect that the increase available by rewinding is not going to be huge.... 10-20% more would be about as much as I would expect, and I would wonder at the longevity due to the increased heating.

 

[Cali rider]

....My testing was pretty straight forward, I monitored for the regulation of the output of the alternator/regulator, and increased RPM until I got back to 14.2 volts, under various loads....

....With the H4 on Hi, and the H7 lit, it took more than 2K RPM to maintain the regulation..... as I recall , it was much closer to 5K on the tach to get back to where the system was producing a 'hard' 14 VDC........ this would indicate to me that the alternator was continuing to produce more current with RPM; at least up through 5K....

That is my point. When the R/R sees a voltage resistance of ~14.4 Volts on the battery side it stops increasing output. Until that happens current will increase with RPM up to a MAXIMUM of 22A.

When I performed my tests, I ran a shunt inline with the positive wire going from the R/R to the battery and measured voltage before and after the R/R simultaneously. You can rev the motor all you want but the system output hits a limit when either of the values listed above are met. I varied loads and saw the results of low voltage as increased amperage up to 22 amps. Rev the motor slightly more and voltage would creep up but current remained fixed. If voltage hit 14.4V, current would slowly taper off. It was 100% consistent.

A different R/R will net an increase in current capability, up to the limit of the alternator. Obviously, at some point you will overwhelm the alternator but I'm sure there is excess current to be used. The R/R dumps it as heat now.

EDIT: Here is the chart I made to show the relationship of RPM, voltage and current.

 

[Cali rider]

..I will look into the R/R from a FJR as there will be one next to the FZ in the basement when I get home. :innocent: might have to "borrow" it from dads bike...

There you go. Let us know if it mates up directly or requires some cutting/splicing to join. Be sure to monitor all voltages and currents as you run your tests.

This might turn in to the Next Big Thing...

 

[dean owens]

great info. thanks for sharing guys. i'm even more looking forward to the outcome of this thread.

 

[bmccrary]

So its my understanding the the voltage regulator is the filter for the system. It prevents the system from boiling the battery and over powering the lights. Limits the volts to each system correct? So if the charging system produces more, the regulator still limits the overall output to each system. However, as it stands now I am not producing enough power to efficiently charge the system with all the addition draws. With more current supplied to the system I will now be able to maintain that charge with the extra power supplied. Think of the rewound stator as a reservoir of current to be used.

One problem with changing the a FJR regulator is that the entire system is designed to run on 12 volts or what ever, not what the FJR is set for. I.E. I could pop important components such as the ECU....

-bryan

 

[alanrim]

One problem with changing the a FJR regulator is that the entire system is designed to run on 12 volts or what ever, not what the FJR is set for. I.E. I could pop important components such as the ECU....

-bryan

The main purpose of the RR is to regulate the voltage, and that voltage is the same on all modern bikes, eg a nominal 12V system.

The FJR is a standard 12V bike so using the RR shouldn't cause a problem on the FZ it will still limit the voltage just the same as the standard RR does. It MAY allow more current to the bike when needed but the 22amp current limit mentioned is more likely a limit of the internal resistance of the alternator than the RR.

In the good old days the Honda Superdream RR became the usual replacement for a lot of manufacturer RR as it was bullet proof (all our Suzuki GS550 had a Superdream RR fitted).

 

[D-Mac]

I'm anxiously awaiting the outcome of this project. I would LOVE to be able to run more heated gear/aux lighting on my bike without killing the battery.

 

[bmccrary]

I'm anxiously awaiting the outcome of this project. I would LOVE to be able to run more heated gear/aux lighting on my bike without killing the battery.

Yea I was thinking about you when I found out this is an option. I am hoping this works out well!

Going to call Gary at Custom Rewind tomorrow and try to dig up some answers for yall.

-bryan

 

[ant_mb]

Yea I was thinking about you when I found out this is an option. I am hoping this works out well!

Going to call Gary at Custom Rewind tomorrow and try to dig up some answers for yall.

-bryan

That's awesome Brian. I've been over loading my system for a while now, and would love a solution as well.

 

[buzzbomb]

The main purpose of the RR is to regulate the voltage, and that voltage is the same on all modern bikes, eg a nominal 12V system.

The FJR is a standard 12V bike so using the RR shouldn't cause a problem on the FZ it will still limit the voltage just the same as the standard RR does. It MAY allow more current to the bike when needed but the 22amp current limit mentioned is more likely a limit of the internal resistance of the alternator than the RR.

In the good old days the Honda Superdream RR became the usual replacement for a lot of manufacturer RR as it was bullet proof (all our Suzuki GS550 had a Superdream RR fitted).

RR stands for Rectifier/Regulator, so it has two purposes. It has to firstly convert 3 phase alternating current (AC) to a DC current so the system can use it. Then it has to limit the voltage to 14.4 volts, and also regulate the current supplied to the system. It's limited to 22 amps, but it only supplies up to 22 amps when it's needed. The battery is the "storage" not the generator. And these bikes are fitted with generators, not alternators. Alternators have field windings, and the regulator varies the current through the field windings to produce higher outputs in the stator depending on electrical load, so they can generate higher outputs at idle than generators; generators have a permanent magnet which rotates around a fixed stator. The moving flux (magnetic lines, like on earth going from north to south poles) cuts through the windings in the stator and induces a voltage. The windings are wound in a 3 phase configuration, so you will have 3 white wires coming from the stator, which are converted by the RR to a DC current.

Hope this helps. I'm interested to see if a different RR could increase the wattage of the charging system. According to the service manual for the 2005 FZ6, it's meant to produce 310watts at around 5,000rpm. Not sure about the S2 FZ6s...

 

[Motogiro]

Here's another interesting article with some variation on theory and design with reference to these charging systems. An interesting concept is regulating the output with a load across the output of the charging system which to me seems very inefficient because you're still using energy (converted to heat) regardless off actual requirement of the electrical system. I'm wondering if our RR system is the same shunting type regulator. I would hope that it would be more like field regulation in an alternator but realize we're not using an electromagnetic field but then we might use stator regulation instead. It would be more efficient than shunting.

Good post friends!

Technical Article: How a Motorcycle Charging System Works - ElectroSport Industries

 

[Cali rider]

...And these bikes are fitted with generators, not alternators. Alternators have field windings, and the regulator varies the current through the field windings to produce higher outputs in the stator depending on electrical load, so they can generate higher outputs at idle than generators; generators have a permanent magnet which rotates around a fixed stator....

Yes, technically you are correct. I am using an obsolete term "alternator", but operating principles are still relevant. People of my age were familiar with both devices in our youth and tended to categorize AC-producing units with external R/R as "alternators" and DC-producing units as "generators".

I will refer to it as a generator from this point forward.

Here's another interesting article with some variation on theory and design with reference to these charging systems. An interesting concept is regulating the output with a load across the output of the charging system which to me seems very inefficient because you're still using energy (converted to heat) regardless off actual requirement of the electrical system. I'm wondering if our RR system is the same shunting type regulator. I would hope that it would be more like field regulation in an alternator but realize we're not using an electromagnetic field but then we might use stator regulation instead. It would be more efficient than shunting.

Good post friends!

Technical Article: How a Motorcycle Charging System Works - ElectroSport Industries

Nice find, Cliff. It explains the system with absolute accuracy, especially the dispersal of excess generator output as heat. This image shows the FZ6 layout:

 

[alanrim]

"Dictionary of Automotive Terms
Alternator
A device which produces alternating current (AC) by converting the engine's turning (mechanical) energy into alternating electrical current at all engine speeds. The AC must be rectified (converted from AC to DC) before reaching the car's electrical system . The alternator is driven by a belt at the front of the engine. Alternators replaced the direct-current (DC) generators used up to the 1960's because they were less efficient especially at idle. The electrically demanding options like air conditioning forced the use of alternators over generators. "