Charging system 99 RSV

[hmlemons0608]

I'm going to throw this out there for feedback, hoping that I am wrong with my diagnosis. Back in July my RR took a dump. I replaced it with an aftermarket RR from DB Electrical after checking the stator resistance and output to make sure that it was not also faulty. I made a 2000 mile solo road trip at the end of August with no problems. Everything seemed to be fine. The bike is my daily driver so there isn't any down time. About 2 weeks ago, on my way home from work, it started to sputter an misfire and then it just died. I called a friend and 2 jump starts later I made it home. When I pulled the RR I found water in the plug and considerable corrosion on the connections. Since the problem was cause by moisture and not a defective RR, I purchased another one from DB Electrical. I charged the battery and my charger malfunctioned and cooked the battery. I replaced that with a lithium battery. With the new battery installed and the RR and connector replaced I proceeded to check the charging system out. The stator still checks out good. The winding resistance is .3ohms with no continuity to ground and the output AC voltage is 26v at idle up to 110+v revved to about 4k. The Lithium battery has a no-load full charge voltage of 13.4v. When I start the bike and check the voltage at the battery I would expect to see about 14v but all I get is battery voltage and it drops when I increase the RPMs. I disconnected all accessories and pulled the headlight fuse and the idle charging voltage rose to 13.6 volts but still drops to battery voltage when RPMs are increased. I'm not sure where I should go from here. The only added accessories I have are incandescent passing lights and an LED tail light bar.

[MiCarl]

I had a customer bring me a VT1100 Shadow that he said wasn't charging. I put the meter on and it was 14.2V at idle. I thought he must be mistaken. As soon as I gave it some throttle the voltage dropped to battery voltage.

 

In his case it was the Regulator/Rectifier.

[hmlemons0608]

That is where my suspicions are leaning but I didn't want to admit that I just threw away 75 bucks on the aftermarket R/R.

[Rick Butler]

Henry,

 

I've attached a fault finding diagram I found on the ElectroSport site (one of the manufactures of motorcycle stators and rectifiers), which I've found to be very helpful in situations like this. And they also provided a diode testing procedure for testing the diodes in the rectifier which I've also attached.

 

Hope this helps,

 

Rick

Electrical fault-finding-diagram.pdf

Diode-testing-guide.pdf

[hmlemons0608]

Just a quick update. Since everything was pointing to a loose connection somewhere, I rechecked all of the connectors again for the 10th+ time. Then I went back to where it all started; the R/R connector. The new plug connector came with crimp on ends, so that is what I did when I first changed it; so I took it back apart and soldered all the ends on to the wires and put it back together. I then started the bike and put the meter on it, not expecting any change, but there it was 14.1 volts at idle and when I rev it up it drops to 13.9. I think I can live with that. Who'd a thunk it?

[hmlemons0608]

on the positive side; I lightened the weight of the bike by about 14 pounds by switching to the lithium battery. The new battery weighs just over two pounds. Has anyone else changed to a lithium battery? How well do they hold up over the long haul? Just curious.

[Condor]

Most of us are switching to AGM batteries. Yes they are heavier than even the OEM Yuasa's, but perform very well. Lithium's seems to have a problem in rough environments, and are also susceptible to premature failure caused by excessive heat and even fire. These are the same batteries that grounded the 787 fleet due to them failing. As far as saving 14 pounds in weight, I don't feel it makes all that much difference when dealing with an 850lb bike plus the rider...or two...

[hmlemons0608]

I know that 14 pounds don't mean squat, but I was looking for a positive to all the problems of the last 2 weeks. The battery that I fried when the charger malfunctioned was an AGM battery. It was in the bike when I got it and never gave me any headaches. If the lithium gives me any grief I'll switch back; providing the bike survives.

[uechi kid]

Maybe I'm wrong but I thought I read that when replacing the stator and R/R with a high output set the connections should be soldered.