[McLovinST3]

Hi folks, need some tech support here. 2005 ST3 with a 4 year old battery. Always plugged into a tender. I went for a beautiful 40 minute ride and bike ran great, as it always does. As I was returning and going down my driveway, I stalled the bike (very rough driveway, so I go really slow). Or maybe it just chose that moment to die.
Lost all electrics. I switched off the ignition then switched back to on. No power. Nothing. No display to instruments, and pressing the starter button produced nothing and no sounds. Tried a few times. Dead Duc.
I then proceeded to check and reseat all fuses, disconnected the battery leads and cleaned the contacts and reattached same very tightly. swapped underseat relays with eachother. Finally, I removed the Magic Blinker units that I had recently installed and reconnected all lighting wiring back to original.
Tried igniton again: Totally dead instrument panel and ignition.
Put battery on tender for a few hours, and tried again, still dead. Voltage measured at battery was around 13.86.
This is the biggie: connected car battery to Duc batt, and bike electrics came back to life and engine started. All indicators on instrument panel looked good. I ran the revs up above 3000 and the voltage at duc batt measured 14.something. (this may have been the car voltage.) When I disconnected the jumper leads, the bike died, and would not restart. Only if jumper cables from care were attached. So, I cannot really measure the stator output or RR goodness because once I disconnect the running bike from the car batt, the bike goes totally dead.
Here is a very weird symptom to add: now, when I connect the bike battery, the immobilzer light and the turn signal indicator blink very rapidly, and a faint buzzing sound is coming from the instrument panel.
This makes me think that maybe the RR is bad. But, would a dead or marginal battery do this?
I am willing to buy a new batt to try, but only if the concensus is that it is the batt. Otherwise, to the shop she goes.
Thanks and hope to hear all the collected knowledge out there.

 

[tonered]

A battery is cheap, much less than a shop to diagnose. Give it a try.

BTW, what is your batt voltage immediately after it stalls?

Also, I am more and more pleased with Stick's recommendation to keep the battery on a tender for only a certain amount of time a day using a vacation light timer. I have it set for 10p to 2a. I see the exact same voltage every morning, 13.1V and consistently see higher volts during the day than when I was cooking the battery day and night on the tender.

Have a good one.

 

[Gearbox]

Quick question - If you set the fast idle lever to give you a steady , say , 3000 rpm and then disconnect the jumper leads does the engine still die ....By then she should be running on the alternator ?

What if you just take the bike battery out of the equation and clamp directly to the bike leads , if you still get the 'electrics' and she starts and runs OK then it would suggest the battery is faulty in some way.

 

[rspcharger]

Quick question - If you set the fast idle lever to give you a steady , say , 3000 rpm and then disconnect the jumper leads does the engine still die ....By then she should be running on the alternator ?

Definitely try this. If it still dies then there is no charging going on, ie a dead alternator or something supporting it. Whatever it is could have died on your ride and you were eating up the stored energy in the battery until your arrival in your driveway. If that's the case you need to go buy a lottery ticket, cause your a lucky unlucky man.

 

[KarlFitt]

I had an issue with mine, all electrics going dead.
would come back to life after some rest.

Under the front fairing are two relays, one is the headlight relay, the other is a main power relay.
My main power relay was bad, replacing that fixed my problem.

And as far as leaving a battery on a tender all of the time, if you use a smart charger that sense battery voltage, leave it on all the time.
I use one that not only senses battery voltage, but it has a mode which is supposed to actually reverse sulfation (and prevent it of course).
Bought my bike 2 years ago with a used battery. Always on the charger when I'm not riding it. So battery is at least three years old and i have never had a starting issue that was battery related (Just that before mentioned relay)

This is my charger (I don't make any money off of this recomendation)

Battery Minder Plus BM12v117 | Batteryminder 12v 1.3 Amp Battery Charger / Maintainer

 

[JasperST4]

And as far as leaving a battery on a tender all of the time, if you use a smart charger that sense battery voltage, leave it on all the time.

+1
My ST was used when I bought it and I got another 6 years out of the battery on a Battery Tender Jr. A good charger should adjust and give you a float charge to just keep the battery in top shape.

Go through all of your wiring, it could be that the amps from the car battery are enough to overcome the resistance in your connections while the bike battery (even in prime shape) is marginal. Clean and use dielectric grease on everything.

 

[McLovinST3]

It was the battery after all!
All my angst and deep thinking when it was indeed the simple explanation. Occam's Razor has it right.
Ducati electrical systems are a deep and mysterious area; much like a woman's...you get the idea.
Thanks for the help, this forum is The Best.

 

[Gearbox]

Good outcome and cheap too !

 

[tonered]

Excellent. You might want to give Stick's method a try. I have both a Deltran Battery Tender maintaining our car and Schumacher 1.5A tender for the ST. The 4hr cycle allows each to go into float mode for a while, but I believe that allowing the battery to rest is a good idea also.

A month or two won't hurt, but monitoring the volts may surprise you.

Have a good one.