Kawasaki Vulcan Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
19 Posts
Discussion Starter #1 (Edited)
Just found out the battery on the Vulcan (that I just bought) is dead.

I bought the motorcycle last Sunday and it has been sitting in my garage while I search for a phantom oil leak. Two days later, when I went to start it today to warm it up before an oil change, I discovered the battery was dead.

It is reading 8.7Vdc. I guess the previous owner charged it up enough to show me that it was running, then told me it was a new battery.

Hopefully he was lying and its really not a new battery, because if it is, that means it's not being charged properly…a much bigger problem. Sheesh. Every time I start working on the bike I find something new.

So, does anyone happen to know what the charging voltage at the battery terminals should be when the bike is running? I'm trickle charging the battery now, and will put it back in just to test the regulator voltage with it running.
What idle speed should I test at?

I'm hoping that it's really just a dead battery and not a bad charging system..ugh.

This poor 900 has been neglected for so long by the previous owner I'm almost tempted to social services.


Thanks!
 

·
Registered
Joined
·
7,620 Posts
You're right to diagnose instead of assuming.

1) What year is the Vulcan 900? 2006 and 2007 models were notorious for charging system failures, specifically; the Stator.

If the battery is not sealed; check the water level. But the battery voltage is concerning. A dead 12v battery is 12.00 volts (without load). Fully charged is 12.6 volts. Below 12.4 volts is where the battery can be damaged. 8.7VDC tells me 2 cells have completely failed; which is common when sulfating has occurred and they have shorted out to one another from corrosion. If voltage comes back up you're fine, but it's unusual for a battery to dip that low and 'survive'.

Charging voltage at 3,000 RPM's (rev it, and hold it, to about what it sounds like cruising on the highway. Use the idle adjusting screw on the right hand side if you have trouble, just don't forget to adjust it back down) should be between 13-15v, per the manual. Double check your manual (I don't have mine in front of me), but I believe that's the spec on the 900. If it's not, post here and let's diagnose it before we start throwing parts at it.

If the battery is brand new and has failed, then it probably has a warranty. There should be a date on the battery. What's very possible is that it has a charging system problem, in classic fashion of "throw a part at it", when it died after a ride and wouldn't start the PO bought a new battery, when it died again they decided to get rid of it. Let the battery discharge or stay discharged and it's now internally corroded. BUT, if it IS new, then it should be replaceable wherever it was bought from.
 

·
Registered
Joined
·
19 Posts
Discussion Starter #4
Thanks for the suggestions. I have a battery tender and will likely have to buy a replacement battery. I don't see a date on it anywhere. I can pull the battery from my other bike and test the charging currents with it in the meantime.

Now about that oil leak….

thanks!
 

·
Registered
Joined
·
19 Posts
Discussion Starter #5 (Edited)
Greetings,

I posted a video my charging voltage. It seems to be in range at idle. When i barley increase the rpm it goes up to about 14.2. But if I increase the rpm higher it drops off to 13.9. Also, no matter what rpm it won't seem to go over 14.2 vdc. I'm not sure if this is normal.

Peek at my Youtube video I made today and let me know what you think. (View in HD so you can see the meter readout.)

https://www.youtube.com/watch?v=LvXaxduQvtE

Was the test done correctly?

FYI - After the test I went to Autozone to load test the original battery and they said it was toast. So I bought a new one which is charging right now.

Lastly, Can someone please tell me where the plastic connector for the stator plugs into the R/R? I'd like to check the three AC wires for resistance while the bike is not running. Then i'd like to check them while the bike is running for AC output.

Maybe I'll just replace the stator at this point. Mine is a 2007 model that has issues with the stator.
 

·
Registered
Joined
·
11,756 Posts
Your charging voltages look fine.
I recommend against digging around looking for faults that are not there for fear of introducing one.

As an add, resistance readings between stator yellows are useless.
 

·
Registered
Joined
·
19 Posts
Discussion Starter #7
Your charging voltages look fine.
I recommend against digging around looking for faults that are not there for fear of introducing one.

As an add, resistance readings between stator yellows are useless.
Your comments are reassuring. But can you please explain why reading between stator yellows are useless?

thanks
 

·
Registered
Joined
·
11,756 Posts
1. Your meter probably is not that accurate.
2. If the specs call for, say, 3.2 ohms and yours reads 3.5, is it bad? Not likely.

The only useable test is the one where you check for a yellow wire to be shorted to ground.
Any fault that may exist between yellows can be detected in other more reliable tests.
 
1 - 8 of 8 Posts
Top