new reg, new stator, new battery, still poor charge

[LaGrasta]

Admin: starting a new thread, merge if needed.

I was stranded on the freeway this past weekend, dead battery. The system is doing the same as it has been for some time, in spite of all new items. It began over a year ago by melting the 30a fuse holder. I replaced it with a circuit breaker per forum suggestions, and it breaks often. Regardless of rpm, just over 13v is all that happens. I guess there is a harness drain/short/problem. Although I have inspected it numerous times, I will begin again.

Thoughts, suggestions?

[PJPR01]

Have you replaced the alternator?

[LaGrasta]

the stator is the alternator.

 

https://www.electrosport.com/collections/street-motorcycles-moto-guzzi-2003-v11-sport

 

Edited February 11 by LaGrasta

[gstallons]

Set the record straight.

 Stator=the portion of the alternator charging system that remains stationary.

 Rotor= the portion of the alternator charging system that rotates/spins .

[Weegie]

I'm not quite sure I understand, you state poor charge then say a 30A breaker is tripping often? I'm unaware of this mod but guessing it's replacing fuse 3 on the output from the charge circuit to the battery.

If it's tripping at 30A then sounds to me like the Alternator is doing its job, but system voltage isn't rising above 13.0 V.

Could be a short, but I'd have thought you'd find that quickly either through blown fuses or smoke.

Obvious start fully charge the battery with an exeternal charger then let it rest for a few hours and check the float voltage.

Battery acts like an accumulator (or resevoir), if its voltage is low it can drag down system voltage and although a long shot it wouldn't be the first new battery that's been found defective

Next thing after that would be to check battery voltage not being dragged down by parasitic load or small leakage. So the battery is low when you set out and will take time to rise in voltage.

I'd also shoot a mail to Electrosport and ask them what the RR output voltage is set to as well, 13.0 volts sounds a tad low to me too, I'd think 13.5-14.0 volts is where it should be. It isn't catastrophic IMHO but is a bit low.

EDIT

Just to add I'm ASS-uming the rectifier ground/earth/chassis is good and of course battery ground, poor grounding usually results in higher system volts AFAIK, but it may be worth checking.

Brighter minds will chip in soon (I hope)

Edited February 11 by Weegie

[PJPR01]

I can see why someone would change only the stator instead of the whole alternator due to cost issues...but it doesn't make sense to me that the conclusion is that the alternator is working properly...otherwise, the battery would not be draining.  If while the bike is running (not just at idle), but also at revs, and you're only seeing 13 V and not 13.5 to 14.2V, somehow the charging system is not working.  Unless you have some serious chafing somewhere, that points back in my experience to a failing alternator, so even with a good stator, the charge is not developing.

I'm probably wrong...but if you can't find any smoking/burnt wires or loose connections, I'd try a new alternator.

Edited February 11 by PJPR01

[LaGrasta]

Hmmm, so I didn't consider changing the rotor. I did clean it a bit, before reassembling the new stator, looked good.

I did fully change the battery (lithium), and it's been sitting on the bench for three days, let me go measure now… 13.43.

[audiomick]

6 hours ago, LaGrasta said:

... changing the rotor. ...

That was the problem on my V35 Imola. It has a Bosch alternator originally, not the Ducati one, but anyway...

I didn't actually have battery problems, but noticed that the charge light came on at higher revs. Seems like the problem was, the surface on the rotor that the brushes run on was a bit out of round, and maybe the springs behind the brushes a bit long in the tooth. Result: at higher revs the brushes started to float and loose contact.

A new Bosch rotor would have been fairly cheap, but I bought a very expensive one from Silent Hektik to match the electronic ignition from them that was already in there. Not sensible, but I had the money at the time...

[PJPR01]

Another thought…how old is the alternator belt?  Is it hard and cracked…perhaps it’s actually slipping on the alternator and not rotating the pulley rotor constantly?

[docc]

1 minute ago, PJPR01 said:

Another thought…how old is the alternator belt?  Is it hard and cracked…perhaps it’s actually slipping on the alternator and not rotating the pulley rotor constantly?

The alternator rotor of the V11 is crank driven inside its "stator", no belt.

[Weegie]

Doesn't sound like the battery then

Usual check on the Alternator is to measure the output wire with a multimeter set to AC Volts

Figures are in the manual I believe, if the same as the Sporti they are

15 V AC @ 1k RPM

40 V AC @ 3k RPM

80 V AC @ 6k RPM

I'm not ruling it out but still leaning toward something amiss in the system wiring or the Reg/Rec

One other thing that intrigued me, it looked like the Reg/Rec was for a 3 phase Alternator, that's fine its just 2 of the phases aren't used.

Oh and the manual also has current figures for the system, looks like it's meant to max out at a little over 27A

Where's @Kiwi_Roy when you need him?

 

[LaGrasta]

Thanks @Weegie, I'll reference your numbers and do this again.

15 V AC @ 1k RPM

40 V AC @ 3k RPM

80 V AC @ 6k RPM

[PJPR01]

12 hours ago, docc said:

The alternator rotor of the V11 is crank driven inside its "stator", no belt.

Thanks Docc...I stand corrected!

[po18guy]

On 2/11/2025 at 9:09 AM, LaGrasta said:

Admin: starting a new thread, merge if needed.

I was stranded on the freeway this past weekend, dead battery. The system is doing the same as it has been for some time, in spite of all new items. It began over a year ago by melting the 30a fuse holder. I replaced it with a circuit breaker per forum suggestions, and it breaks often. Regardless of rpm, just over 13v is all that happens. I guess there is a harness drain/short/problem. Although I have inspected it numerous times, I will begin again.

Thoughts, suggestions?

You have traced the battery ground cable to the transmission case and cleaned/tightened it?

[thumper]

I had high volt readings on mine 14.8 - 15.1 @ 3000 RPM

took each fuse and relay out gave a shot of Deox to them.

14 volts now