Battery Blues, and DUCATI Electrical

[Stick]

Battery Blues:

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!



Battery Tenders:

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…

[jwsparkes]

Great read, thanks for the info,

funny, I'm currently working on a small electrical circuit (PCB about 25mm by 65mm) which connects to the ground and positive wire of the ignition harness and this monitors the voltage of the system and displays as red, green or blue color of a tri-color led. My 996 has a spare position in the dash which was for the alternator failure warning light which for some reason they removed. The led glows red for low voltage (below 12.5) switches to green between 12.5 and 13.5) and above 13.5 glows blue. Circuit draws 30mA while in operation and zero when ignition is off (A later revision might include a timer so that the light only flashes once per second say and hence reduces battery drain and could be wired all the time, a quick glance at the dash will show when it's time to tricke charge).

Anyway, thanks for the read, if anyone is interested I'll write a "how to" for the led voltmeter.

Regards, James.

[Stick]

Geez, I forgot one important thing: Battery Ediquette...When you go to R+R a battery:

Step 1) Remove the wedding ring !!! or other jewelry. I've seen what a few hundred Amps can do if your ring gets between the wrench and chassis. And it ain't pretty. Real pain is you can't get that sizzling hot ring off fast enough, so buddy, you are branded!

2) For most modern vehicles, (-) is chassis. This - lead is "First to break, last to make". Reason being, if you over swing your wrench and touch the frame, if you're on the + post, you've got hundreds of amps flowing, sparks, and might be replacing things like wrenches, alternators, and you're lucky if all that sparking and surging doesn't blow the top off the battery. So going from - to chassis with a wrench is like the - wire itself. Nothing happens.

3) No SMOKING PLEASE! Lead acid batteries emit H2 gas. Remember reading/seeing the Hindenburg? That's what blows the top off of batteries, and simultaneously covers your face with sulfuric acid. Neat, acid trip, eh? This can even happen when you're connecting booster cables, chargers, etc. It's more likely to occur on an auto battery, because they vent right out the top. Ours, if the vent is good, is a tube leading down under the engine. Call me weird, but I always take a deap breath, and blow across the top of mine to disperse any hydrogen gas that might be lingering, before I connect/ disconnect. That's right, Stick blows...

I'm sure there's more, but these are the "top 3" in my book.

[hank]

Great post - thanx!

[Stick]

With all this battery talk, I forgot to mention some IMPORTANT SAFETY PRECAUTIONS:

1) Ditch the wedding ring and other jewelry when working on or near batteries. Under certain conditions, if you over swing your wrench and your ring happens to be between the wrench and chassis, you’ll have a kilowatt heater on your finger. You’ll be branded for life, maybe even lose the digit. Or the massive current might blow the top right off the battery. Can U say acid trip? Ya, right to your damn garden hose…
2) The “-“ terminal. First to break, last to make. When you’re removing connections on your battery. This keeps the likeyhood of #1 from occurring to a minimum. (This assumes a – gnd. System, like our DUCs from the late 70s onward.)
3) Hydrogen! Remember the Hindenburg? Lead-acid batteries liberate H2 when they’re charging or discharging. So, no smoking!!, and try to minimize any sparking near the battery. Positive venting batteries have a slight advantage, assuming the tube is intact. But all you need is one mistake, and you’re paying a trip back to the garden hose, you hoser! This is true when connecting or removing jump starting cables. I tend to take a deep breath and blow across the top of my battery to disperse any lingering H2. All it takes is the right combo of H2 and ambient air, spark, and “pop” (or BANG!). It happened to my cousin who’s a knowledgeable auto mechanic (he’s aware of this issue, yet it still made him a hoser).

I’m sure there are others, like never carry an auto battery up against your clothing (your jeans will disintegrate after the 1st washing), but these are my “top 3”.

[nathanTX]

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!

Very true. My buddy with a M750 had a no-start problem that seemed to be classic bad/dead/disconnected battery. First check I did was terminal connections. Everything was tight and there was no visible corrosion. After troubleshooting every other possible option I could think of, he took it to a mechanic. The mechanic disconnected the cables and discovered a thin, film-like substance that was apparently some kind of corrosion between the terminals and the cables and not really visible without disconnecting them. A few seconds with a wire brush and he was up and running. So, just because your terminals don't look fuzzy, doesn't mean they don't need an occassional cleaning.

Good write up, Stick. Electrical gremlins are the most frustrating to chase, and often the most daunting for the shadetree mechanic to decide to tackle.

[XnewducX]

I have a 99 duc 996s with a 3 phase regulator....then I bought a race motor from a guy and I put it in only to find out that it has the older two phase pre 99 charging system...what am I going to do now?

thanks for the info

jonah

[Ducoddy-SS]

There is NOTHING you can do...you may as well send me the worthless engine,frame and parts...I will do my very best to recycle them so they dont end up in the local landfill..
Mike S

[DukeDesmo]

Originally Posted by jwsparkes

funny, I'm currently working on a small electrical circuit (PCB about 25mm by 65mm) which connects to the ground and positive wire of the ignition harness .

interesting but why not just fit one of these?.......

[SouthsideDuc]

I've got a Battery Tender, but I actually prefer my Battery Minder. It keeps a little higher voltage and the desulphation mode seems to work pretty well. One unit is enough to keep up to five batteries in shape.

http://www.vdcelectronics.com/batteryminder_12117.htm

Tony