Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > 998 / 996 / 916 / 748 > Different Regulator Problem?

[bigtwin]

I have read many of the posts on this topic and all seem to relate to a lack of charging. I suspect that I am suffering from an overcharging problem. A summary of my experience follows:
After experiencing high voltage measured at the battery terminals I suspected a regulator problem. After undertaking extensive tests including checking the alternator continuity/voltage, regulator diode checks and regulator earthing I concluded that these were all ok. However I was unable to verify (no means available) that the regulator was operating satisfactorily. I also concluded that the battery was defective (couldn't be sure if this was an inherent battery failure or as a result of prolonged exposure to a high charging voltage) and replaced this.

After fitting the battery I undertook further battery voltage tests and found that the voltage was stable around the 14 - 14.5 v level regardles of how high the engine was revved. In order to give confidence that everything was ok, I rigged a cheap DVM to the battery so that I could monitor the voltage when riding. Everything seemed ok on my test runs.

However on my last ride, after around 40 miles the voltage started rising slowly to a peak of around 17v. After stopping for around half an hour I set off on my return journey and the voltage had returned to around the 14v mark. After 10 miles or so the voltage started rising and peaked at over 18v!

Can I conclude that the regulator has given up the ghost and any idea how much to replace?

PS
My bike is a 98 900ssie with the three phase alternator and shares, I believe, the same rectifier/regulator as the superbikes.

[Felix]

Try Electrex.

[Shazaam!]

The actual charging voltage can range betwwen 13.5 and 15V (depends on the battery type) according to Ducati. So your regulator's not regulating at 18V. I use a (trouble-free) RR51 from Electrex after going through four Ducati RR's.

[moto748]

Ha! I was going to ask if Electrex do a three-phase unit, but, checking their website

http://www.electrexworld.co.uk/

I see they list a RR51 for the 748 and a RR53 for the 996. (£75 + VAT + carriage)

So I take it that the RR53 would be right for all late models?

[Shazaam!]

For 1999, Ducati redesigned the electrical system, going from the 350 watt design to a 500 watt three-phase system. (Three-phase alternators have three wires coming out of them, single-phase have two.) They produce an AC output that has a higher frequency than the earlier single-phase design so the regulator presumably has to do less work (i.e. less heat) conditioning the waveform and converting it to DC. The RR51 is a single phase unit, the RR53 is a three phase.

Some people have asked whether you can convert a single phase to a three phase system. Not very easily. You'd need to replace the crankshaft, rotor, stator, alternator side engine cover, clutch slave and pushrod, etc.

[Nigel C]

how do i know if i have a single phase or 3 phase ????

[moto748]

Easy. By reading Shazaam's post above.

[Nigel C]

easier said than done my bike is a 99 but has brake calipers from a 98 bike (1 retaining pin not 2 ) so could be a late 98 bike on a 99 plate but has the reg/rect that is from a 99 bike (so i have been told) so i presume louigi at the factory had a set of 98 calipers to get rid of so stuck them on the next bike on the production line .

so i was hoping that someone could tell what i should look out for to tell the difference between the two
(the electric bit that is )

[rockhopper]

Count the wires coming out of the alternator!!

[bigtwin]

Thanks for the replies. Looks like I need a new regulator then - I guess I knew that all along!

Any views on how long before the battery cries "enough enough, I cant take all this voltage any more!"?