Battery sucking wind lately?
You might have 1 or more shorted cells. There's 6 cells in a 12V lead-acid (auto/moto) battery. Fully charged, and at no load, each cell should be 2.2V, so 2.2 x 6 cells = 13.2V. You should try to measure the battery to see if it's close to 13V. If it was just charged, let it sit for 15 or 30 minutes before measuring it. (Good time to grab a beer, grab 1 for me while yer at it.)
If it's 11 ish, one cell is gone. 9V ? 2 cells are gone. If you doubt your meter, double-check it on a car, or another 12V auto/moto battery.
When a cell shorts, the battery will try to overcharge itself, because what's normally a 13.x V (trickle) charger, is now trying to pump 13 V into a 9 or 11V battery, and this battery wants to stay at say 11V. So it does this with more current. You may also get excessive bubbling from overcharging from the remaining cells that are OK. You might even ruin a cheapo trickle charger (ask me how I know!).
It's even worse running the bike, because these newer DUCs (1999 and on) have a 520 Watt alternator. They can push out 40 Amps, and these amps are going to go where they think they're needed---right into your defective 11V or 9V battery. The charging system thinks the battery is low, and it’s going to be pumping a lot o juice into it to try to bring it up to 13.x Volts. Can you say Mr. Bubble?
What the funk is that?
Ever see a bit of fuzz on the posts of your battery? Maybe or maybe not. Keep these posts clean! I was on a trip a few years back, and this gent’s ST2 just stopped. 10PM on an unlit road. Let me tell you, it was not fun trying to get at that ST2 battery at night. Turned out to be the minus post had just enough funk on it to make it an open connection. Dunno why he had a test light with him (the bike was less than 1 year old) but it came in handy when I was able to “find 12V” sitting on the negative wire, where it should have been ZERO VOLTS!!! Oh, and guess who carries a home-made test light with him now…ME!
The above event left such a bad impression with me that I modified the right air conveyer on my ST2, so that I can not only put a wrench on the + battery terminal, but I can actually jump start the bike without the need of removing the fairing.
So wire-brush your terminals, and apply a light amount of grease to them to keep the crud to a minimum. And make sure the battery connections are VERY TIGHT!
While your bike (car) is sitting, your battery is being drained…Someone in here measured 0.6 mA (0.0006 Amps) leaving their battery (with nothing turned on), and while this is not a huge drain, it stresses the need for a trickle/float charger (battery maintainer). The 0.6mA is called a parasitic drain, and if ignored over longer periods of non-use, it tends to discharge the battery and make it susceptible to sulphation (the whitish creepin'crud that "grows" on the battery plates).
I think my ST2 is closer to 2mA of parasitic drain.
Also, I recall reading where some older DUCs in the 1990's had a rubber boot that held the starter solenoid that needed to be trimmed back from the + wires because the rubber was impregnated w/ carbon, and was conductive, and was adding too much to this drain amp #. So you might want to glance at that, too.
When a battery is fully charged, it won’t sulphate.
The other nice thing about a topped up battery, is that the charging system on the bike does not have to work as hard to recharge the battery, as compared to say, a battery that was only ½ charged to begin with.
Charging system on a DUC:
Most of the Ducatis from 1992 thru 1997 had 350 Watt alternators, with 2 wires (single phase AC) on the output. These 2 wires carry AC voltage and current up to the RR (Regulator/Rectifier) which changes the AC to DC, and Regulates it to about 14V AT HIGHER RPMs. At idle, the bikes are not really charging the battery. My ST2 (1998) actually DISCHARGES the battery at about 1 Amp at an idle. On my ST2, I can see a decent amount of charging, even at 2000 RPM. And I’ve seen as high as 14.5V at full charge. I thought this was a bit high, but the OEM battery never boiled or lost any of its acid over time, and I ended up getting over 7 years out of it, so 14.5V must be an OK number….
There’s a big fuse on the newer DUCs, close to the battery. One might assume it’s a “main” fuse. Nope…it’s a big fuse (30 or 40 Amp) that sits between the battery and the RR. I know it will blow if you connect your battery backwards (NOT RECOMMENDED). We’ve had a few people that have mistakenly done this, and it takes the fuse out, and LUCKILY, they didn’t damage the RR. Newer, most 1998 and on have a 3 wire (three phase), 520 Watt alternator (and the 40 A fuse).
Older 2 wire systems were notorious for overheating the connector between the stator (the alternator windings) and the RR. Up until 1998, these connectors were really sub-standard, kind of a cheapie “pin and barrel” connector. My 1998 ST2 had an automotive-style, weatherproof connector, so I thought I was all set. Well, at around 22K miles, it decided to become a crispy critter like it’s older cousins. I decided to remove the connector, and went with solder, heat-shrink tubing, and some wire loom. No more problems, unless I want to remove the engine, which hasn’t been removed in it’s first 26000 miles…. BTW, the 1997 (Euro) ST2 and 1998 ST2 had a 420W, 2 wire alternator. I pound the crap out of mine (with 110W of added lighting, and 30W heated grips), and I have not had any other problems with it.
Hey Gino, where canna I stick this thing?
On the older SBKs (916, 748, 996, 998) DUCATI, in their infinite wisdom, placed the RR BELOW and BEHIND THE BATTERY box. This places the RR close to a hot front head pipe. At speeds of 60 to 160 mph, this MIGHT be ok, because the RR wants to shed heat from its aluminum fins. But in town traffic, the RR will be stressed from the added heat. Some gents have opted to rewire and relocate the RR to a cooler area. After going thru a few RR’s, one place that Mr. Buckelew chose was the “muddy” side of the license plate.
Plenty of cooler air back there, and Mark said that he hasn’t blown one since. I recall Mark also added a 20 A fuse in the AC wires as an added level of protection. But I do recall him saying that these occasionally would blow…
‘Nuff 4 2 nite, I might toss together an electrical diagnostic session for your starter circuits as a future article…