Scoot overcharging battery? By glavey (Read 11,720 times)

[glavey]

Well, I bit the bullet and bought a flywheel puller designed for the 139qmb. As soon as it gets here, I'll post pics of the stator.

[Bashan]

I messed up, that's all I can say. I've been telling people something for a couple years and I think it's wrong. If you're wrong the best thing to do is admit it.

I was testing my wife's old Bashan for a project and I started getting findings inconsistent with what I expected. I tested the stator and got the following results. I'm testing the stator wires at the R/R. They run right back to the stator so it's just like testing off of the stator pigtail. The first two are OK, what I would expect.

This is how I was telling people to test the stator, one wire at a time. It used to work for me, I did this countless times. The first one is not all that much of a shocker, kinda low but I've seen it, this is with RPM:

But the yellow...huh? It should have been less than the white since it's center tapped. Again this is with RPM:

So let's take both wires off and try it, this is pretty high for a white, or so I thought.

At least the yellow follows the center tap theory although still awfully high:

With the wires hooked up and regulated I didn't find this all that abnormal":

I'm not sure what happened. Did I have a massive brain fart? Is this stator toast? Have R/Rs changed that much? I'm sorry Glavey, I think I steered you wrong. However, I do think it's either your stator or R/R so I don't think you've spent any bucks that you wouldn't have spent anyway. I'll just to have to go do some more metering and figure out what happened. I'm sorry folks if I gave you bad info...very sorry. Rich

[glavey]

No worries Bash, people make mistakes. If there is any testing I can do (albeit with my half-working electrical system) to help you confirm or deny any ideas/theories/hypotheses let me know.

[Bashan]

Thanks man, that's very gracious of you. I've been doing some testing since I posted that and I think the problem is the myriad of R/R's that are out there. They all tend to deliver the same results as far as voltage but do it in much different ways as far as internal components. When you pull one wire off of a R/R now the internal components react much differently from one R/R to the next. While before they all seemed to be pretty much the same as far as reacting to yanking a wire. I have a box of different R/R's and I've been going through them getting bizarre results. So I think the R/R's are the problem and I'm going to have to figure out a way to test stators without throwing in the variable of each R/R reacting differently. I'm still not sure why this stator is cranking out those high voltages. It's a carbon copy of the one I floated the ground on for the Trail Tech R/R and I never got those readings off of it. I'll figure this out. Rich

[Bashan]

I just talked to Jack about this, I think he has it figured out. We'll work this out, I'll keep y'all up to date. Rich

[Bashan]

Just an update on the testing debacle....I think my stator is bad and the R/R is toast too, I'm going to have to start over with good components. I'm in the middle of swapping an engine out though and will have to put this off for a bit. The only spare stator I have around here is a three phase. In the meantime we still need to pull the flywheel and check out the stator on your bike Glavey. Rich

[glavey]

Ok. The package is due by Wednesday so I should have pics by then.

This whole situation really makes me wish I knew enough about electronics to design and build a R/R myself.

[Bashan]

OK, I got it figured out. You can't use the one wire tests anymore on the modern R/R's. They use such diverse internals on them now to do the same thing they all react differently. So here is how you check out your W/Y/G stator charging system:

1: Unplug your stator pigtail.
2: Set your multi to AC voltage (up to 100v AC if not an auto ranger) and ground one probe IN THE STATOR GREEN CONNECTOR OF THE PIGTAIL. Do not ground it to the frame to avoid interference. Put the other probe in white wire and start the engine. Give it some RPM and you may get up to 60v AC or even a little more. Down to 40 would be acceptable.
3: Same procedure for the yellow wire, it should be a little less. If the voltages aren't within these ranges your stator is bad. Plug the stator back in.
4: If the stator voltages are good start on the R/R. Leave the R/R PLUGGED IN. Set your multi to AC low volts, no more than 50. Ground one probe to the R/R green to avoid interference. Test the yellow wire, you should get 10 to 13 v AC depending on RPM and what lights are on.
5: Test the white wire the same way, up to 15v AC is acceptable, less than 12 suspect.
6: Test the battery terminals set at DC with some RPM, 13 to 14.75v DC is acceptable. Anything outside of the above parameters is a bad R/R.

[glavey]

Ok, I will do those tests tomorrow.

P.S. How often is your avatar going to change? I swear I saw that... thing in my dreams last night.

[Bashan]

My avatar changes when it beckons me to do so. Yes Eeky? I hear and obey.

[glavey]

More test results!

All tests were at about 6k rpm except for the battery test; I got up to about 4k rpm.

With the multimeter probes at the disconnected stator pigatil:
Yellow: 45v AC White: 57v AC

Probes at the connected R/R:
Yellow: 14.12v AC White: 18.27v AC

Probes at the battery:
15.28v DC

[Bashan]

Stator tests are normal, the regulator/rectifier tests are marginally high on yellow. But the white wire is dedicated to charging the battery, it is high as is the charging voltage. The regulating circuit for the charging circuit is failing. The diodes are still cranking out DC voltage but they will soon fail under the stress. At that point the DC voltage will plummet. In any event, your R/R is toast. Rich

[glavey]

That's good to hear. I'll still probably take the flywheel off and see if anything looks bad; I bought that flywheel remover and I'm going to use it at least once!

I'll order another R/R from someone different this time.

One question, on page 2 of this thread, I posted a screen shot from partsforscooters. In it, the bottom left R/R was just for the 139qmb (50cc) and the bottom right was for the 157qmj (150cc); so 2 different R/R's, one for each engine.

In all of the ebay and amazon listings I see, they say that the same R/R will work for 139qmb and the 157qmj.

Thoughts?

[Bashan]

I just used my flywheel remover twice today. If you are going to mess around with scooters you will not regret having one around. I will now go look at the pics you referenced and get back in a bit. Rich

[Bashan]

As long as it says it's compatible with a 139QMB, AND the regulator and connector look exactly the same, AND the original did not have FLP stamped on it anywhere, AND then the new one is not FLP, you should be OK. I know that sounds paranoid, but these R/R's are NOT universal, I don't care what these vendors say. Did John ever get back to you? Rich