Battery - Electrical Issues

WarrenJ · April 17, 2010, 06:33:43 PM

I seldom ride at night, but tonight I took a 20 mile spin and noticed when I pulled the clutch in at stops, the lights would dim quite a bit. The last several times I have been out, after the ride I noticed a strong acid smell near the top of the bike. Am I having voltage regulator issues or is it something else - thoughts?

ducpainter · April 18, 2010, 03:37:09 AM

You need to put a voltmeter on it to find out.

Howie · April 18, 2010, 03:42:48 AM

It sounds like you are overcharging, which would kill your battery and cause other problems. Put a voltmeter across the battery. With the bike running at 3K RPM, if you read over 14.2 volts, you need a regulator.

WarrenJ · April 18, 2010, 04:37:39 PM

Put a voltmeter on it tonight. Started out at 14.4V then suddenly went to 18 - 19volts. The bike is a 2000 750 with 7600 miles on it. When I bought it @ 2600 miles last year, the voltage regulator was shot and the seller put a new one in before he sold it to me. What eats the regulators? I see CA Cycleworks has regulators that are from Honda for the Monsters - how are those working out? What can I do to cure the problem instead of treating the symptom of fried Voltage Regulators?

Oldfisti · April 18, 2010, 04:50:18 PM

Quote from: WarrenJ on April 18, 2010, 04:37:39 PM
Put a voltmeter on it tonight. Started out at 14.4V then suddenly went to 18 - 19volts. The bike is a 2000 750 with 7600 miles on it. When I bought it @ 2600 miles last year, the voltage regulator was shot and the seller put a new one in before he sold it to me. What eats the regulators? I see CA Cycleworks has regulators that are from Honda for the Monsters - how are those working out? What can I do to cure the problem instead of treating the symptom of fried Voltage Regulators?

A defective stator just plain won't charge anything so it sounds like that's fine.

I do recall some of the older superbikes had issues with the regulators failing due to the part overheating. Did the previous owner replace it with a brand new part or used?

Replace it and see if you can do anything to keep it cooler than it now is.

Sorry that's all I got for the moment.

WarrenJ · April 18, 2010, 05:26:35 PM

Thanks - looks like replacing the regulator is the first step in any case. I did some reading about putting heavier gage wires and better connectors on, also saw some things on using heat sink compound behind the regulator - I'm not sure that was done when the last one was replaced. Looks like I get to learn some new stuff again!

WarrenJ · May 15, 2010, 07:31:51 AM

So I put in a new voltage regulator and installed some heavier gage wiring. I have run the bike a couple weeks and it seemed to work fine. Took it for another night drive last night and I'm having the same dimming issues and checked the voltage across the battery this morning and I am back to 19 volts. WTF!!!!

Any ideas on what is frying my regulators??

2000 Monster 750 w/8300 miles

Speeddog · May 15, 2010, 07:53:10 AM

Got nothing right at the moment.

I'll think on it.

suzyj · May 15, 2010, 02:24:38 PM

Did you replace the battery when you replaced the regulator?

The battery and regulator work as a team - if the battery is shot (and your battery is shot if it's reading 19 volts) then it won't put any load on the regulator, and the regulator will have to dissipate more power than usual, resulting in its early demise.

Another thing I'd check very carefully is the wiring. If there's a loose connector in the battery/regulator circuit, either in the ground lead or positive lead, it can kill the regulator in short order.

Finally you should check your stator voltages. It's possible for one of the windings to be damaged but for the stator to still appear to work, as it has two other windings. What happens here though is that all the power is running through a couple of the diodes in the rectifier bit of the regulator, stressing them and eventually causing failure.

So you need to be methodical in your testing - don't just replace parts without an understanding of what's happening. Measure voltages at different points and different RPM, and note them down, and that will quickly identify what's wrong.

The regulator is a pretty crap design, but not so bad that it will blow inside a week.

WarrenJ · May 15, 2010, 02:42:47 PM

Thanks for the input. I went through the test procedure for checking the stator and the regulator out of the bike and they both tested within parameters. (if I did everything right) I am coming to the conclusion that it is the battery. These issues started last fall (Northern Hemisphere) when I had a low speed lowside. After that I noticed staining on the left side of the frame from acid from the bike. I assumed(you know what that does) that the acid was from the drain hose being knocked off the battery but it may have been that the battery was damaged at that point.

The question I wanted to ask you is - would a defective or damaged battery in the system cause a reading of 18V across the battery terminals during operation or would it have to be from one or more of the other components of the system?

I appreciate your help and I am certainly interested if you come up with an upgraded regulator system for the monsters!

suzyj · May 15, 2010, 02:56:15 PM

Quote from: WarrenJ on May 15, 2010, 02:42:47 PMThe question I wanted to ask you is - would a defective or damaged battery in the system cause a reading of 18V across the battery terminals during operation or would it have to be from one or more of the other components of the system?

Yes. There's a term called load regulation that's used to specify regulators. A good regulator will have "tight" load regulation, so the out put voltage will be (say) 14.2 V with no load, and only drop to (say) 13.8V with a heavy load (charging the battery).

On most vehicles, the load regulation isn't important, as the lead-acid battery will hold the voltage within spec. On a healthy battery, the voltage only changes by maybe half a volt between no load and heavily loaded, and indeed between no charge and heavy charge.

I haven't pulled a Ducati regulator apart, but from everything I've read and witnessed, it's a terribly crude affair, so will have very poor load regulation. This is the reason I wouldn't want to use one with A123 cells, as putting more than 3.8V across each cell (15.2V for the series connected pack) will shorten the lifespan of the pack.

As you've seen, the ducati regulator doesn't mind putting out well over 15V if it doesn't have a healthy battery to hold it within spec.

WarrenJ · May 15, 2010, 03:02:47 PM

Thanks for confirming my sketchy diagnosis. Hopefully the battery store has one in stock so I can ride tomorrow. I had to eat my heart out today as about 500 bikes went past the farm and I was sitting here with my Duc in pieces.

WarrenJ · May 16, 2010, 11:17:04 AM

Added new fully charged sealed battery - still 18V across the terminals when running. NOW WHAT!!?

suzyj · May 16, 2010, 11:58:40 AM

At this point I'd get someone else to have a look - a fresh set of eyes can be very useful.

Possibilities:

Your multimeter is shot, and giving you incorrect readings.
Your new regulator is shot, either from when you bought it or from its week running with a stuffed battery.
Your new battery is shot. How long have you run it at 18V?

WarrenJ · May 16, 2010, 12:33:51 PM

I checked my readings with a second good multimeter and the readings agree.

I ran a series of tests from Electrosport - a flowchart for motorcycle charging systems and except for the high voltage across the battery when running, the regulator was within specification

I checked the regulator using the diode test function and everything checked out to spec from Electrosport.

I ran the battery 30 seconds - just long enough to check the voltage across the terminals.

News:

Battery - Electrical Issues