Charging system question/issue

[Anonymous]

No, actually I am thinking about it all wrong. My contention would be true if the wire in question set the total resistance for the circuit. As the current through the circuit is determined by other components, you are right. Resistance in the wire will heat it. Too many years, and too many beers! :roll:

But I am certain that automotive and cycle electrical systems are compatable.

[earlfor]

Having the car running puts you in the position of having two charging systems charging the same battery. The 100 amp output of the car alternator is going to fry the bike battery. Maybe in theory, you can do this, but in practice, I can say youre going to be very sorry you did.
I have never seen a charging circuit with two alternators charging the same battery. Two batteries connected by jumper cables is one battery as far as a charging system is concerned.

I=E/R is perfectly clear. No problem there. :-) I am interested in hearing your explanation of this.

With a corroded wire and increased resistance in the wire, if you apply a load to the wire (say a headlight), the headlight may have a consumption of 6 amps. It requires 6 amps regardless of the wire condition. Consequently, if the added resistance in the wire is equal to 3 amps, then the drain on the battery is 9 amps through the wire up to the point of resistance/corrosion. Its like a strainer, what goes through the strainer is 6 amps. The other 3 are converted to heat. I have observed a lot of wires melt their insulation off and turn yellow at the point of resistance. If device load/draw remains constant, then amperage must increase to overcome resistance. Heat increases. If this were not true, then no wires would ever burn up.

Earl

I'm sorry, but this is not really the case. A (12v) motorcycle system runs at 13.8 - 14.6 volts, or thereabouts, just like a car. Having the car running won't hurt anything. Regarding resistance, I=E/R where I=current, E=voltage, and R=resistance. You can see that, as R goes up, I must go down. This means less current at higher resistance. Since energy (watts) = current times voltage, this means that the circuit (the wire, in this case), is dissipating less energy, therefore, less heat.

Hope this helps.

[Anonymous]

That would be true if you hooked them in series. Of course, when jumping you are hooked in parallel. The amps available doesn't determine the flow, rather the ratio of voltage to resistance does. The fact that the car voltage is identical to the bike means that no more current will flow with the car up hooked than without it, when when the bike is running. In practice, I have jumped many bikes from a car, and have never had an issue.

[earlfor]

So you are saying it is OK to have alternators from two different vehicles charging the same battery simultaneously?

Earl

That would be true if you hooked them in series. Of course, when jumping you are hooked in parallel. The amps available doesn't determine the flow, rather the ratio of voltage to resistance does. The fact that the car voltage is identical to the bike means that no more current will flow with the car up hooked than without it, when when the bike is running. In practice, I have jumped many bikes from a car, and have never had an issue.

[schinae]

Jumping a motorcycle from a running car seems to be the cause of about 80% of the electrical problems we diagnosis and fix at the shop where I work. I wouldnt do it.

[earlfor]

Agreed. Dont do it. If you need to jump from a car, do it without the car running and everything will be fine.

E.

Jumping a motorcycle from a running car seems to be the cause of about 80% of the electrical problems we diagnosis and fix at the shop where I work. I wouldnt do it.

[earlfor]

Hmmmm, I would have to say yes, but only in some ways. :-) :-)

Earl

But I am certain that automotive and cycle electrical systems are compatable.

[Anonymous]

The 6 amps for the headlight and 3 amps for the bad connection totalling 9 amps is wrong. Think of it as 2 ohms for the light and 1 ohm for the bad connection. The total of 3 ohms will result in a reduced current flow in total considering that the origanal resistance was only 2 ohms.

[earlfor]

OK, that makes sense. So why does reducing flow cause the wire to melt?

Edit............strike that question. :-) It was late last night and I was obviously running on about 2 out of 4 cylinders. :-)

Earl

The 6 amps for the headlight and 3 amps for the bad connection totalling 9 amps is wrong. Think of it as 2 ohms for the light and 1 ohm for the bad connection. The total of 3 ohms will result in a reduced current flow in total considering that the origanal resistance was only 2 ohms.

[Anonymous]

It isnt the reduction of flow that melts the wire it is the bad connection alone. Even if there is reduced fow, it is still enough eventually to cause heat at the point of resistance. Think of the amount of heat given off by the bulb. It is designed to do this. The bad connection has trouble radiating its heat especially as the insulation acts as a thermal insulator.

[earlfor]

I think we have finally come round robin to agreement. :-)

Earl

It isnt the reduction of flow that melts the wire it is the bad connection alone. Even if there is reduced fow, it is still enough eventually to cause heat at the point of resistance. Think of the amount of heat given off by the bulb. It is designed to do this. The bad connection has trouble radiating its heat especially as the insulation acts as a thermal insulator.

[Anonymous]

Alright, so did I screw things up using the charger on not? You guys seem to know your stuff pretty well, compared to myself whom admit am really in the dark regarding this stuff.

Everything from the wiring to the the stator, the regulator/rectifier, to the battery has been mentioned as being my problem. I know you guys, even knowing as much as you do, can't be expected to just diagnose my bike in an online forum, but all the help I can get is useful. With all that I have mentioned, is there any kind of a concensus on what my problem most likely is?

Thanks for all the replies, the help is appreciated!

[Anonymous]

Thanks, 3phase. Regarding damage to cycle charging systems from jumping, it isn't due to too much amperage. But it sounds like experience suggests not to do it, so I'll defer on that point. Although... why were they jumping in the first place? Electrical problems? Maybe a self selecting sample? Anyhow, OP, a bad connection anywhere in the charging/battery circuit will cause a voltage drop that will make the lights go dim, blinkers not blink, the coils go weak, etc., and there will be heat at the point of the bad connection. The same symptoms will happen if the charging system is not working, but if you charge the battery on a charger, they will disappear for awhile, then come back. If that helps at all.

[earlfor]

OK, lets first try to isolate the cause, then we can work on how to fix it.
You may have shorted your new battery by overcharging. I would disconnect the battery from the bike and charge it at a 2 amp rate (the lowest on a charger usually) and check the battery voltage with a meter every hour or so until the battery shows 13 volts. Then disconnect the charger from the battery and let it sit for 12 hours or so still not connected to the bike. Check the battery voltage. If the battery is still showing that its holding a charge greater than 12.8 or so, then it is probably ok.

Then reconnect the battery to the bike wiring harness. As you said, the red wire on your regulator/rectifier is hot, so I suspect your R/R is history.
However, the first check you need to do is the stator. Oftentimes, a faulty R/R will fry the stator also. Your stator is 3 phase and should produce 80 volts AC at an engine rpm of 5000. Three wires on your R/R will be from the stator. Those three wires are normally yellow. There should be 5 wires in total on your R/R. Black is 12 volts negative and goes to battery negative. Red is 12 volts positive and connects to battery positive. The 3 yellow (or remaining three wires if they are different colors than yellow) are AC input to the R/R.

To check the stator, disconnect the three yellow wires from the R/R. Set your multimeter to the AC 200 scale . You said you were not familiar with the meter, so the scale should be located at about 2 oclock on your dial and be noted ACV. If we number the three now disconnected stator wire 1,2 and 3, you want to connect your meter probes between 1 and 2 and run the bike to 5K rpm. that phase is good if it reads around 80 volts at that rpm. Next, connect the meter leads between wire 2 and 3, run bike to 5k and you should see 80 volts on that phase. finally, connect the leads between wire 1 and 3 and at 5K rpm you should see 80 volts there also. If all three phases show voltages above 70 volts, your stator output is within limits. 80 volts on each phase is factory spec.

If your stator checks OK, then reconnect the stator to the R/R. Set your meter to the DCV scale 20. Connect the red meter lead to the battery positive and the black meter lead to the battery negative. Run the bike to 5K rpm. The voltage at your battery terminals should peak between 14.3 and 14.8 volts. It should not rise above 14.9 volts regardless of any rpm increase. If voltage is below 14.3 or above 14.9 at 5K rpm, then your R/R is faulty.

Also, tighten the wire connection to your starter and check the battery ground wire between your negative terminal and the top of the transmission where it is bolted down. Make sure both are clean and tight.

Lemme know what you get and we can go from there.

Earl

Alright, so did I screw things up using the charger on not? You guys seem to know your stuff pretty well, compared to myself whom admit am really in the dark regarding this stuff.

Everything from the wiring to the the stator, the regulator/rectifier, to the battery has been mentioned as being my problem. I know you guys, even knowing as much as you do, can't be expected to just diagnose my bike in an online forum, but all the help I can get is useful. With all that I have mentioned, is there any kind of a concensus on what my problem most likely is?

Thanks for all the replies, the help is appreciated!

[Anonymous]

Excellant! Steps an idiot like me can understand. I will follow those steps this weekend. I have already tightened the wire at the starter and the ground at the trans is also good, I checked that the other day as you had instructed.

Thanks to all of you for help, I'll get back with the results.