Hi everyone,

I am having doubt here regard the charging for my bike, need some advice.
Thank.

As i follow the "Fault finding flow chart for motorcycle charging system", fully charge my battery (12.48 VDC and it hold there). After connected to my bike it read about 12.28 VDC.

Ok, here come the funny part which i don't really understand.

When i Rev to 2500rpm it read about 14.2 VDC, but when i rev to 5000rpm it read about 13.8 VDC.
Is this normal ? As according to the chart it still with in the range.
But according to the chart it should be higher then 13.8 VDC at 2500rpm and lower then 14.8 VDC at 5000rpm.
For my understanding is that, the higher the rev (rpm) the higher should be the voltage right?
In this case, is the other way round, what may be the cause? Or is it normal?

Thank.

Most likely the rectifier is faulty.

Hi, everyone.
Have check the charging again with a new rectifier. Notice the result i have the last time is correct just a bit more.
That is when rev at 2500 rpm measure at the battery (+) and (-) read 14.4 VDC. And rev at 5000 rpm it read about 13.8 VDC to 14.0 VDC.
So correct me if i am wrong, the higher the rev the less will be the charge, of cause there is a minium amount it should charge. Have check with two more bike and even my small little van also the same (rev a bit more then 5000 rpm, it have the same charge as 5000 rpm.)

Thank you.

Charging voltages are only approximate. Any voltage between 13,5 and 14,5 are OK. The battery itself will charge as soon as the voltage is above 12.4 V.

Why did you start measuring in the first place ? Did you have any problems ?

If it ain't broke, don't fix it.
_________________
Poul
"If Life Gets Boring, Risk It!"
MC21SE, KISS box
MC21SP, HRC box, racing loom

Hi, pbekkerh

Thank for the kind reply.
I start to measure it, due to two issues.

1. My battery won't last me, i have change quite a few of them and wondering where goes wrong.

2. Last week during my joy ride, all the sudden the bike dies off, and since the bike is still moving, i release the clutch as if perform a push start, the bike start but without headlight. So i disconnect the headlight while riding. When reaches home the bike dies off, cannot start at all. I waited till next day and try again, well it started. That is when i start to measure the charging and the battery. Because i ever have such issues before, by disconnect either one headlight or charge the battery, the problem will goes off for a while.Well this issues have been there for some years, have went to a lot of workshop, but no one can give me a good answer, but just ask me to disconnect one headlight and ride....

That is why i am hungry for an anwser.

Thank you.

It sounds like a charging problem. It could be intermittent. A short or an open circuit, only sometimes.
What is the battery voltage when driving with the headlight on? Maybe install a small voltmeter, so you can check it while riding.
_________________
Poul
"If Life Gets Boring, Risk It!"
MC21SE, KISS box
MC21SP, HRC box, racing loom

Hi, pbekkerh
Just got myself a voltmeter for the bike. As i know there are ways of connecting it up, but is there any recommended way? As MC28 are running on card rather then key. I thought of connecting it direct with a switch and a fuse in between, but still not the best way.
Can anyone give me some advice?

Thank you.

Normally you just connect it after the ignition key. That way, it'll turn off when ignition is off. I guess there will be a fuse for the ignition, so you don't need to install that either. Check out the MC28 schematic in the members section for a suitable place to tap the voltage.

For testing purposes, connect it directly to the battery via an inline fuse, like this.


You could then use the fuse as a switch. This way you can check the batt. voltage before and after, you turn on the ignition.

Later when problems are solved install the voltmeter as described on top.
_________________
Poul
"If Life Gets Boring, Risk It!"
MC21SE, KISS box
MC21SP, HRC box, racing loom

Hi pbekkerh,

Thank for the advice, have install the volt meter on my bike.
Notice something that i would like to ask, hope you don't mind.
Is like that;
During idling my rpm is about 1k to 1.2k (Is it a bit low) the volt meter read about 12.0 to 12.2 vdc.
When i start to move normally it goes up to around 13.0 to 14.5 vdc max, rpm about 2.5k to 5 ~ 6k.
Ok, if i increase my idling a bit high and let it stay around 1.5 k rpm, the volt meter will read about 12.8. Of cause the fuel consumion will be more, but will it help regard the charing, or is it meaningless.

Please advice, thanks.

At 12.2 the batteriy is not being charged but how long time are you idling ? Normally you only idle a short time.

The other readings are looking good.

The normal idle for a NSR is 1500 rpm anyway.
_________________
Poul
"If Life Gets Boring, Risk It!"
MC21SE, KISS box
MC21SP, HRC box, racing loom

Hi pbekkerh,

Thank for the reply,

Well in the country i am staying (Singapore), there are a lot of traffic lights around. Unless moving on highway, almost everywhere about a few hundred meter will have a traffic light. We have to stop if it turn red, if not we will get into trouble. Therefore, idling are very common here.
By the way i have adjust the idling a bit higher about 1.5k rpm. Now the volt meter read about 12.5v, hope it will help a bit.


Thank.

kyocrane wrote:Hi pbekkerh,

Thank for the reply,

.......................... We have to stop if it turn red, if not we will get into trouble. ...............................

Its a bit like everywhere else in the world

You could change the bulbs for the brake- and rearlights to LEDs, that will save a few watts. If you drive with lights on in the daytime(like the EU) you could install a LED drivelight for daytime driving, that could save 30 watts.
_________________
Poul
"If Life Gets Boring, Risk It!"
MC21SE, KISS box
MC21SP, HRC box, racing loom