| Author | Message | ||
     Curve__carver |
There seems to be more bad information than good in regard to the charging harness. Hopefully this proves useful. This is a copy of an email exchange. It is OK to share. Mods, maybe this can be a sticky.... ---------------- Can you explain the logic in the 1125R Race ECM that controls the operation of the charging harness relay? I am trying to better understand the operation of my charging system. ----------------- For starters it is the same as the updated OE strategy. The charging system has a narrow RPM band where the output of the system is high but the oil flow to system is low resulting in the system generating more heat than it can dissipate and overheating if operated in this band for an extended period of time The ECM monitors time the engine operates in this band. If the engine is in that band for an extended period of time it uses the relay to open one leg of the 3 phase charging system reducing charging output and heat generated. After a period of time it will turn the leg back on returning the charging system to full output. The ECM monitors battery voltage while doing this and will turn the leg back on if it ever drops below a minimum threshold. The system has logic built in so that short excursions out of the RPM band do not reset the timer resulting in the strategy not activating to protect the charging system. The exact time the relay remains on or off is not a fixed value. It is calculated by the ECM based on several factors. ------------------- Thank you for the explanation. Can you tell me any of the actual parameters, such as the minimum threshold for voltage when the 3rd leg will kick on? On public forums, there is quite a bit of mis-information on how the charging harness actually works. It's hard to know for sure if it is working as designed or if I have a legitimate charging issue. ------------------- There is indeed a huge amount of very bad information on the forums. It has caused a great deal more trouble than help. As mentioned below, the ECM calculates using information from a 3D table based on a time and battery voltage, with hysteresis both in the RPM band and time, so there is no direct or simple answer to that. Voltage fluctuations are normal in the affected RPM band as the leg is turned off and on. Some people watch for this and think it is an indication of a problem. In most cases it is not. If the system goes bad, it will go down in output considerably. | ||
| Reepicheep |
A very clever hack! | ||
| Puddlepirate |
Thanks for posting this! (Message edited by puddlepirate on March 13, 2012) | ||
| Curve__carver |
So...the charging harness isn't a perfect solution, but it is a solution. A better solution is the EBR kit with no charging harness. Let's face it, HD wasn't about to put $900 in parts into your 1125 when the charging harness cost them MUCH less. On a cold start, the the voltage should be around 14 for the first minute or two. Depending on the variables that the ECM is monitoring, voltage will fluctuate after that. At idle, with both fans running, your voltage may drop to the point where the battery light illuminates. That DOESN'T mean you stator is failing. It means the harness relay is protecting your stator from burning up, at a cost of less than perfect charging. It's a compromise. If voltage begins to climb when the motor is back at higher rpms, your stator is most likely just fine. Voltage fluctuations will put more strain on your battery, which may shorten battery life. I think battery tenders are a good idea for most motorcycles, I think they are an especially good idea for an 1125 with the harness relay. I personally have 12k on my stator with the harness relay. Most of my rides take me hundreds of miles from home. It can be unsettling to see voltage drop or to see a battery light at idle, but I've never had to push. Hopefully, this is helpful. | ||
| Bartone |
So... this only applies to the race ECM and not the oem one? Curve, what ecm are you running? | ||
| Curve__carver |
This goes for the current flash of the stock ECM and the EBR ECM. | ||
| Puddlepirate |
So with the EBR kit, the harness is not needed or recommended? | ||
| Curve__carver |
Others have reported that EBR doesn't recommend the harness relay with their stator kit. | ||
| Baf |
Correct, the harness isn't needed or recommended with the 08/EBR kit. | ||
| Timebandit |
> "If the system goes bad, it will go down in output considerably." That's the important take-home point that I've been driving home all along -- that when your bike is stuck in the 12V range, then you're running off of the battery and the charging system is broken and needs to be fixed. For some people, this problem can be as simple as making sure that the relay hasn't been toasted. One thing that's important to keep in mind before a latecomer starts professing that people are posting "wrong" information is that people who have been providing insights into how the electrical system works have been doing so by disclosing bits and pieces of the system logic. Nobody's offering you the complete picture -- not on the forum, and not in that email. We have Gemini to thank for disclosing the RPM-based logic thresholds. In the field testing by several different BadWebbers has confirmed that his disclosures are correct. Anyone with a VOM can confirm that RPM is first criterion upon how the charging system switching logic is based. There are secondary considerations based upon measurements of Vbatt and some hysteresis to avoid over-switching. that really shouldn't surprise anyone who understands these systems well enough to design them. It's funny that someone wants to huff and puff that the people who provided us with this helpful information are "wrong" because they didn't provide us with a complete disclosure about every logical aspect that is included in controlling the charging harness. To complain that the RPM-based information is "WRONG" is just not accurate. The RPM-based information is RIGHT. It's just that there are also other factors that come into play that nobody told you about... yet. Look at the Ducati vreg patents and you'll see that Duc has patented designs for "smart" controllers, which adjust regulated voltage based upon the state of the battery. People who have done their homework have known this for a long time. They've also known about ECM interfacing with the charging system. This is nothing new. When it comes to hysteresis, that's not an earthshaking disclosure to anyone who knows what he is doing when it comes to design engineering. Smart design engineers know that the process of switching the stator from 3-phase to single-phase output has thermal cost associated with it -- when the stator legs are switched on and off, there is a significant back-EMF that's generated due to the inductance within the stator coils. Any smart design-EE isn't going to go switching the stator legs on/off willy-nilly (looking only at RPM), as the back-EMF that is generated with the cut-offs creates it's own heat in the stator. If you're interested in minimizing heat, you want to be selective about how often the switching takes place; if you weren't, then the thermal cost of changing phase paradigms could end up generating more heat than it saves! If you designed a switching system that didn't take this into account, you could have a switching system that generates more heat than it saves. Doing that would be pretty effing stupid. No smart engineer would go there. I'd be reluctant to profess that other people had it "wrong" just because they didn't tell you the whole story. It's possible that they dumbed-down the engineering mumbo-jumbo, simplifying the overall explanation to the point that everyone could easily understand what was going on, and left out some of the details. As an example, it was difficult enough to overcome the longstanding belief on this forum that the harness relay switched off one leg of the stator. It took a lot of effort to lead people to the point that they could think their way through the problem to realize that in a 3-phase circuit, two legs are cut off by interrupting one. The whole 3-phasing vs. 1-phasing concept took a long time to sink-in. Doing that got people to understand the most significant aspects of how the charging harness update actually works. Now that we're at that basic level of understanding, people are ready for more details about how the system works. To nitpick and say that the people who explained things were "wrong" is nothing short of disingenuous. The information that was posted here is right, it may have just been abbreviated as an intentional act of making it comprehensible for the majority of the end users in easily-digestible bites, with the intent of adding more information as the community was able to assimilate it. | ||
| Zac4mac |
Don't worry too much Bob. Reverse engineering rarely is a perfect fit with development disclosure. Close is good, often good enough. You did well on this front IMHO, no need to be defensive. "Latecomer"'s info looks like it comes straight from EBR. works for me. Fine tuning a "different" solution is what Buell was always best at. Z | ||
| Curve__carver |
Zac, A well thought out perspective. | ||
| Nattyx1 |
This is all endlessly fascinating... and it reminds me why I spent all my collegiate time on the other side of campus. :-) I've always been a pretty good Wrench, but once my science classes started getting HARD (namely because they began demanding a lot of icky math!), I skedaddled over to the arts.  Which begs my question (perhaps already answered in one of the other 4398 threads on this subject - apologies if so): What should a non-scientist with skills and tools like me actually DO? My bike: 2010 CR, 9k miles, has had 3 stators - harness installed between stators one and two. Running EBR ecm matched to pump gas and fmf pipe. I have 1500 miles on the current stator and all seems fine. (Yes I am knocking on wood as I write this.) Would one of you boy-geniuses please point me to the threads where there's a concise and reliable plan laid out as a course of action? I'd like to ride my bike to Laguna for MotoGP (for example) but I don't wanna get part way there with my group of fast friends and then get stuck. That would be an ignominious outcome of the highest order. Thank you. | ||
| Reepicheep |
I'm watching the threads because there is a great engineering exercise going on here. But I am not invested (I have a Uly, so my stator is fine). I think there are two clear "happy paths". The best is to get the EBR stator kit. Very pricey, but the problem is solved. Second best is to go to the earlier system (2008, right?). Might be cheaper, but might be just as much as the EBR kit, so why not get the machined stator bell as well). So also pricey. Third is to start getting creative. Re-wrap and re-pot the stator. If it were me, I would do it with a little thicker wire and a few less windings (I'd aim for 10% to 15%). And send your stator bell to EBR (or somebody else) to get that hole machined. You are exploring, but it could be a lot cheaper. Fourth is to wait and see if Harley is, out of integrity and their commitment to their customers, actually going to own and fix the problem... or if they are just waiting out the clock on warranty claims to dry up. Ha. Ha ha ha. ha ha ha ha ha ha ha ha ha ha. | ||
| Sparky |
Reep, if by "stator bell" you mean "rotor", please refer to it as a rotor for the benefit of those who may be not as familiar with the charging system as others. We don't want to have people trying to find a stator bell in the service or parts manual, not find it and be even more confused.  For my 2¢, I would likely be exchanging my '09 rotor for a modified EBR one AND go for a series VReg like the CE 605 SB from Roadstercycle.com and hope for the best. |
