This morning I took the bike for a visitation at Dr. Louigi Moto, known to some of you on these pages.
I charged the battery overnight on Thursday, not Friday, so it could be left disconnected for a day or two. It was OK this morning and the bike fired up no prob at all. Rode over to the good Doctor's (say about 15-20 miles), taking a meter with me. Check the voltage on arrival: all fine. 12.4V on idle lights on. 12.7V on idle lights off, 14-14.2V at 3500rpm lights on.
That looks spot-on to me!
We both agreed that the most likely source of the prob is not the bike at all, but our old friend, the alarm.
The alarm has been giving trouble; in fact, the alarm fitter was supposed to replace the unit last week. I'll be chasing him up at once. Although the alarm doesn't stop me using the bike, all is clearly not well with it. When I hit the zapper, the indicators flash, but the alarm only gives a whimper, instead of the normal "beep". As Louigi said, it's entirely possible that an internal short in the alarm unit is draining current from the bike. After all, the voltage dropped to under 10V after a couple of days when connected on the bike, but only dropped a fraction when charged and disconnected from the bike. Back home from my run out, the reading is now a healthy 13V again.
So who ever said Ducati rect/regs and batteries where unreliable?
Good news is, if this is the case, I'll cost me nowt.
Tha way forward seems to be to get a new alarm unit fitted ASAP next week (this'll be done under warranty), and then see if I still have a problem.
Hopefully, not!
Of course I knew all along that the alarm was a bit dodgy, but because of past experience with batteries and rect/regs, I'd (wrongly?) dismissed it as a cause.
[Edited on 2-10-2004 by moto748]