Scoot overcharging battery? By glavey (Read 11,716 times)

[glavey]

I just did a few tests with a multimeter and a 55w headlight connected to my scoot. With the scooter off battery voltage was 12.92. With the scoot on and having the brake lights and turn signals on, the lowest reading I got was 12.56. With the scoot running at idle without the headlight on the voltage at the battery was 16.2. Peak voltage w/o headlight at the battery was 17.34. AC voltage measured at the headlight connector was 17.9 at idle.

Those seem way too high for me. I'm assuming I need a new rectifier/regulator, correct?

[Bashan]

Yes, that's too high. Yes, you need a R/R. Don't run it like that, you'll toast your battery. The max voltage while the bike is running should be 14.5v DC.

[adamhoyer]

I replaced mine and my battery is still at 13.50 off and 16.50 at rev

[Bashan]

I'm sorry Adam, but that is outside of spec. Either your R/R is faulty or the stator is cranking out way too much juice for the R/R to handle. 14.5v DC is the top limit at the battery terminals. I have hooked volt meters up to every bike I've ridden and that's what comes in with RPM, and that's what the manuals say. Rich

[adamhoyer]

I read some electricity off my face with the multimeter too.

[Alleyoop]

If it charging at 15 and over it is overcharging and will eventually kill your battery(PERIOD). Even your cars the charging rates are the same if it is charging in the 14.5-14.7 that is OPTIMAL.
Alleyoop

[glavey]

I got a new Regulator/Rectifier from scrappydog and since I just drank an energy drink, I couldn't resist doing some testing on the old and new R/R, scooter wiring, and charging/lighting coils in the stator.

I used this service manual's specs to test everything.

The charging coil on the stator measured 0.8 ohms, spec is 0.2-1.2 ohms. Lighting coil measured 0.6 ohms, spec is 0.1-1.0 ohms.

In the service manual, the way the wires were connected were different than what I observed on my scoot; the yellow and red wires were switched. Perhaps this is what killed my old R/R (and battery). Below are the measurements I took using the manual and my observed connections.

Here are the manual specs:

I'm not quite sure what to make of all of this. All of the values measured from terminal-to-terminal are way more than what the manual says and there is continuity between wires that shouldn't have it and vice versa. The old R/R didn't have any continuity to the outer metal case and the new one does.

Honestly I'm a little scared to connect this R/R to my scoot for fear of the battery going boom or shorting out something that I can't afford to replace.

Can someone else look at the wires coming from their R/R and tell me if they are the same as the manual or like I observed, or even something different still?

I should mention now that my scoot is a 2011 taotao atm50-a1 with a 1p39qmb.

[Bashan]

The old manuals are toast on this subject, the wire config on an R/R is now this:

The top has cooling fins, the bottom doesn't. If the wires are different than this it's hooked up wrong and that is your problem. I've had a lot of trouble ohming out a modern R/R. They are all different and resistance doesn't mean a lot anymore. Check the stator voltages, if they are correct and the R/R is hooked up like the diagram, it should be 12v AC on the white and yellow hooked up, and 14v +-.7 DC at the battery. Read this article by Mike Floric, it says it all.

[glavey]

Thank you for that link, it explained quite a bit to me.

As you said; testing resistance seems to be pointless now, but what about basic continuity; specifically the way my old R/R had no continuity between any of the pins and the exterior metal case and the new one seems to have the case grounded?

One interesting thing about the R/R from scrappy; it has a clearish slightly squishy potting on the bottom so you can see one side of the pcb and the components on it. Most of the soldering is quite good although the joints near the pins are a little... unsavory. I'll take a picture tomorrow.

Also, is there a current pdf/text/anything documenting 50cc/150cc chinese scoots?

[Bashan]

About the only continuity you'll get is from the ground pin to case...on MOST of them. Sometimes not. Some of them ground through the case to the frame and you have to have a clean frame mount. Others, it's the ground pin completes the circuit back to the stator. In the past, I have wired the ground pin to the frame, ground the stator to frame, and made sure the R/R attachment to the frame is a good contact. , cover all bases.

So you want something documenting Chinese scoots? You mean a good, hard and fast reference/manual?....no. You have to find your way using the manuals as a loose reference. Just like with the R/Rs, some of it applies, some doesn't. That's why you've got to learn concepts, get a multi, and get a feeler gauge. If you understand what's going on, you can find your way. Hmmmmm..a manual..good question.....maybe some of you other boneheads could offer a suggestion. Here's one I like that is so often overlooked....The Z Bike. But again, it's not going to match everything you need...use it as a guide. And there's always the clinic for posting question if the manual lets you down. Rich

[glavey]

For those interested, here is a picture of the new R/R with clearish potting along with a few terminals I cut off and re-crimped. The crimps were actually quite good, but the material used was poor.

[glavey]

Another update: Dammit. I got the new R/R hooked up along with the newly re-crimped battery-to-starter solenoid and battery ground-to-engine ground cables also with a new I'm guessing 10 gauge battery ground-to-frame cable.

Before I started the scoot I measured the resistance between various exposed metal frame bits, engine parts, and the R/R and all of them were at or near 0.3 ohms, which is what my multimeter zeros to with leads touching.

I started the scoot and checked the dc voltage at the battery 13.5 and climbing. 13.9... 14.2... 14.5... 14.7 (at this point I was screaming internally STAY THERE!!)... 14.9... 15.2 (Ah crap)... 15.5... 15.9. That's the highest it will go with full throttle and minimal running lights. On the AC side, things were much better. Measured at the headlight; the voltages never got above 11.9 with WOT.

One thing I did notice was that when I had the headlight, brake light, and turn signals all on, the battery voltage peaked at 15.1. I should mention now that I have led tail and brake lights, removed the stock headlight and headlight housing and have a 55w h3 headlight with an on/off switch. My thinking is that these R/R's could have been made to keep the voltage at 14.7 with all of the stock incandescent lights always on.

If my understanding of how the R/R works is correct, it regulates the voltages by feeding only what it is designed to feed to the respective wires and convert the rest to heat, thus the need for the heatsink fins on the metal case.

What if I just wired a 5/10/20/30 watt resistor into the scoot to bring the voltage down to where it should be?

[Alleyoop]

You are avoiding the real problem BAD R/R and are trying to compensate for it not regulating the DC power.
alleyoop

[Bashan]

Can you give me a link to that R/R? I can't find it on the Scrappy site and I've never seen one like that. What are those connections you took off? Those are not from an R/R. An R/R just has pins. Where's the heat sink on that R/R? I think you have the wrong part.

[Bashan]

OK I found one....live and learn: