As the title of the topics says, about a month ago I had a stator failure. This is the second stator failure on my '13 Glee.
From your description it sounds like you got two -12 stators with the glue defect. As others have mentioned, the recent recall was due to a manufacturing flaw and the misapplication of glue that allowed the wires exiting the coil to vibrate and thus abrade the insulation causing a short.
This is a different failure mode than the general (and unavoidable) degradation of the stator coil insulation due to heat over time. This is the failure mode that the series R/R is suppose to address but it comes with caveats. Based on the original design (with or without a series R/R) the coil insulation is a wear item
due to high current densities in the stator coils and the always-max-output (at a given RPM) of a permanent magnet generator.
Just wanted to put this out there as a heads up to any of you that think you are out of the woods for a stator failure, just because you've gone with a series regulator. I can tell you all that this latest failure coincided exactly with a quick run to red line. Red line is seen fairly regularly on this bike, but on this occasion it seems high RPMs may have been the cause of the stator failure. No idea what exactly the latest redesign of the stator is supposed to address, but I'm hoping it's rev related. Think I'll send the old stator out for a rewind just in case.
The shunt type regulator dumps excess power into a resistor and is dissipated as heat in the R/R. The series type regulator temporarily (and rapidly) "unplugs" the generator from the circuit to match loads. By disconnecting the load from the generator the current goes down and the voltage goes up on the coils (conservation of energy). The lower current spares the insulation from resistive heating of the coils so it minimizes insulation degradation over time. The higher voltage means that coils will fail with less insulation damage (or a manufacturing defect in your case) compared to shunt R/Rs. I'd bet that your first stator lasted longer behind the shunt R/R than the second stator behind a series R/R (assuming they were both -12's) due to the difference in coil voltage.
Yeah, I'm aware that the stator doesn't move, but the magnets move. The faster they move, the more voltage is generated. I've seen it reported that some regulators have issues with higher RPMs, though I'm not recalling which or what those issues are at the moment. Not being an EE, I don't know how voltage might play a part in frying a stator. I just know that I ran the motor up to red line, and there was immediately no charging voltage/current.
This is correct and with the higher voltage there is a greater chance of insulation breakdown and thus a short. The run to redline probably spiked the voltage on the coils and caused the insulation to fail at the glue flaw. The bottom line is that a series R/R will actually make a defective stator fail sooner than a shunt R/R because of the higher voltages on the coil. The gambit with the series R/R (assumng a non-defective stator) is that the insulation will not degrade as fast with the lower currents and that this more than compensates for the higher voltages. This seems to be a good gamble because many OEMs now use series R/R and the history of real-world proof.
Because of the higher voltages and the fact that the series R/R only prevents insulation degradation and can't undo that damage, I recommend only using new stators behind a series R/R to increase your chance of success. The problem is that if you install a used stator (that was previously behind a shunt R/R) the degradation of the insulation has already begun and there is a good chance that the higher voltages of a series R/R will push it into failure. Used stators are plentiful and cheap on ebay for my model and I didn't want to drop $400+ for a new OEM stator and a series R/R. I bought a used stator for $50 from an SV racer who had a whole cabinet full of stators and I picked up an open-box mosfet shunt R/R kit for $100 which was much cheaper than the series R/R kits. I went with the mosfet for the tighter voltage control and cooler operation which allowed me to move it to the left rear quarter panel but most importantly since its a shunt R/R I can continue to use $50 used stators without worry (so far, no problems).
Regarding the recall, I was doubtful any dealer would want to deal with my customized system. I'll see if I can go the reimbursement route, otherwise, I guess I'll just eat the cost.
I thought I'd read that other DIY'ers got reimbursed for the part but you need a receipt and they want the old stator back.
At the time of the failure, I wasn't running any extras. I do have heated grips, and a heated vest, but neither was being used at the time. My girl also has a heated vest and heated glove liners, but hasn't used them in about a year. Never caused any issues when she did.
With a shunt R/R the bike loads have no effect on what the generator sees because the R/R insures that the bike loads plus the R/R load = generator output. With a series R/R the lower bike loads imply higher voltages on the coils (more power to dump which ends up in coil voltage) but I think this is probably a minor effect.
Interesting that you say a series regulator would draw more current at full load. I was under the impression that the series R/R was more efficient.
The efficiency of the regulator (shunt or series type) is not really relevant to most riders and probably minor. It really only comes into play when you are drawing max power. For example, my K7 DL650 is rated at 375W max output at 5000RPM. Say I am cruising down the road drawing max power to run all my gear and the bike. In that state the OEM, shunt type R/R is not shunting any load but it does have some minimum load to do its job. However that load is not counted in the available 375 watts because that loss is part of the system. Say the OEM R/R minimum load is 10W and I replace it with a series R/R or a mosfet shunt R/R that are 50% more efficient so minimum load is 5W. So that extra 5W would now be available for use but its only a 1.3% increase of the available power. I made these numbers up because I don't know what the actual minimum numbers are for R/Rs but it can't be more than a few percent of rated power. Below rated peak power draw the efficiency of the R/R does not matter because the R/R (of either type) is dumping power so the more efficient R/Rs, to continue my example, would just be dumping an extra 5W instead of using it like the OEM R/R.
I need to find the article but from what I read they level at about 2/3 of the load IIRC.. maybe it was just the heat produced by RR.
I'd like to read it if you can find it.
IMHO if you switching to series replacing head/tail/auxiliary bulbs only makes sense as you are freeing capacity for heated gear.
This makes sense, regardless of R/R type. If you are trying to use more power than the system can supply you have to reduce loads somewhere to free up power for the heated gear or other use. If you have a series R/R and you lower the loads with LED lights, & etc. you are raising the voltage on the coils (the power has to go somewhere if you aren't using it). I think this is a minor effect and probably fine if you started with a new stator as I discussed above.