Ducatti VR/Rectifier 912 ULS. Help!

So just to give an update on this ordeal which apparently came down to one of G connectors from the stator into the rectifier. After all the previous troubleshooting,  the battery was charging intermittently. This time instead of hitting my head against the wall, I called a friend who is a electronic engineer and soon to be A&P to help me further investigate. First thing we did was to rule out the stator with an oscilloscope. According to my friend if the stator is good it should produce a smooth sine wave which it did with the exception that there was a momentary drop at the top of the wave. We are not sure why it does that (if you have any insight on this please share). Next was to measure the DC current at the terminal which produced 15.4v at 2000 rpm.. Bear in mind that I have previously replaced the rectifier/voltage regulator, capacitor, the battery and the 25v circuit breaker. And early in this troubleshooting saga I have replaced the connectors/ wiring to the rectifier. Finally, this time, upon checking one of the G connectors, it looked like it was producing some resistance. We fixed that and now (finally!) the battery is charging although only up to 13.9v.

Hi Calo

13.9 is just fine, it is normally 13.7  up to about 14..2 but of course there are many variables.  As long as you are producing more than 12 you are charging the system.  

Cheers

I ended up eliminating the black plug altogether a few months ago. That ended up being the culprit on my 912 when I had R/R issues. One of the G terminals apparently was a bit loose or corroded and it even slightly melted. All good after re-terminating all of the wires, adding some dielectric grease, and reconnecting them individually. 

Thanks Nicholas. That sounds like a great idea. Do you mind sharing a few pictures of your work?  I am curious to see how it looks without the black connector.

Rotax Wizard wrote:

Hi Calo

13.9 is just fine, it is normally 13.7  up to about 14..2 but of course there are many variables.  As long as you are producing more than 12 you are charging the system.  

Cheers

Yes to the first part, 13.7 to 14.2 is fine, but as to the second part, not exactly.  A voltage of over 12v does not necessarily mean you are charging the battery.  

The fully charged nominal voltage of the EarthX battery is 13.3V. At 13V the battery is about 50%, and at 12.5V the battery is down to 20%. So if you are showing a maintained voltage below 13V, the system is likely discharging.