Charge Voltage

loudhvx
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Re: Charge Voltage

01 Jul 2018 18:35 - 01 Jul 2018 18:37

Sustained 15 volts is too high under any RPM. The manual was written at a time when accurate 1/10 volt readings were not very possible for the home mechanic.
In the summer, 14.3 would be a more reasonable target. You might get away with 14.6 to 14.7 in colder weather, but in the summer it is hard on the battery.

A new reg/rec should not be so high. I would suspect the voltmeter before I would suspect a brand new Shindengen reg/rec (series type or other). Do you have another voltmeter?

Are you sure you have the reg/rec wired directly to the battery? Is the battery in good condition? Does it easily start the bike?

1981 KZ550 D1 gpz.
Kz550 valve train warning.
Other links.

Last edit: 01 Jul 2018 18:37 by loudhvx.

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Nessism
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Re: Charge Voltage

01 Jul 2018 21:15

#786271

What kind of R/R did you get? It looks like a Shindengen but there are tons of fakes on the market so gotta ask.

14.5V at 5000 rpm a good level. I agree that 15V is too high.

Ed
Carb O-ring Kits : www.kzrider.com/forum/3-carburetor/61807...-o-ring-kits?start=0

www.kzrider.com/forum/faq-wiki/618026-new-owner-things-to-know

1981 KZ750E2
www.kzrider.com/forum/11-projects/604901...z750e-project-thread

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gordone
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Re: Charge Voltage

02 Jul 2018 11:56

#786292

Nessism wrote: What kind of R/R did you get? It looks like a Shindengen but there are tons of fakes on the market so gotta ask.

14.5V at 5000 rpm a good level. I agree that 15V is too high.

It`s not original Shindengen, but seller say it`s identical and have sold a lot of them without any bad review, I can see that on ebay also...
I haven`t have time to to alot of testing, but today I measured the battery before I started up (engine stone cold) measured 13.14v.
When I started up and let it be on idle, engine had maybe runned total 20 seconds I measured 14.40-14.44v....

I increased the RPM to 4k and 5k, but the voltage was stable and actual some lower, not much.....

So what is these ? today the test was good, maybe the stator was cold ? it start to make problem when its hot?

The battery is new, but I made a blaim... I was able to cross wire plus and minus in the seat baseplate.... so the battery got warm.....

I talked with seller today of the regulator and he said:
the battery with the motorcycle off must measure 12.80
when the motorcycle is on it must measure 14/14.50 a second if the battery is charged or nop
if the voltage exceeds 14.50 it also controls the stator for the sh775
they go up if the stator is broken

Maybe the battery is broken ?
Maybe the stator is good ?

I can try to take more measurement when the engine is warm?

What do you think ?

1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).

Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine

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loudhvx
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Re: Charge Voltage

02 Jul 2018 12:45

#786294

Since you measured 13.14v on the battery after it has sat a long time, maybe your meter is reading high. Like the seller said, after a long time the battery should be just under 13v, like 12.9 after a day, or 12.8 after a few days. I would try to borrow another meter if you keep measuring high voltages.

1981 KZ550 D1 gpz.
Kz550 valve train warning.
Other links.

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gordone
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Re: Charge Voltage

02 Jul 2018 12:58

#786296

loudhvx wrote: Since you measured 13.14v on the battery after it has sat a long time, maybe your meter is reading high. Like the seller said, after a long time the battery should be just under 13v, like 12.9 after a day, or 12.8 after a few days. I would try to borrow another meter if you keep measuring high voltages.

Will see if I can borrow a PRO one at work and not a cheap one I have

1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).

Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine

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old_kaw
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Re: Charge Voltage

02 Jul 2018 13:13 - 02 Jul 2018 13:44

#786297

gordone wrote:

Nessism wrote: What kind of R/R did you get? It looks like a Shindengen but there are tons of fakes on the market so gotta ask.

14.5V at 5000 rpm a good level. I agree that 15V is too high.

It`s not original Shindengen, but seller say it`s identical and have sold a lot of them without any bad review, I can see that on ebay also...
I haven`t have time to to alot of testing, but today I measured the battery before I started up (engine stone cold) measured 13.14v.
When I started up and let it be on idle, engine had maybe runned total 20 seconds I measured 14.40-14.44v....

I increased the RPM to 4k and 5k, but the voltage was stable and actual some lower, not much.....

So what is these ? today the test was good, maybe the stator was cold ? it start to make problem when its hot?

The battery is new, but I made a blaim... I was able to cross wire plus and minus in the seat baseplate.... so the battery got warm.....

I talked with seller today of the regulator and he said:
the battery with the motorcycle off must measure 12.80
when the motorcycle is on it must measure 14/14.50 a second if the battery is charged or nop
if the voltage exceeds 14.50 it also controls the stator for the sh775
they go up if the stator is broken

Maybe the battery is broken ?
Maybe the stator is good ?

I can try to take more measurement when the engine is warm?

What do you think ?

Whoah, thar a minute.. Now if you hooked the battery up backwards and the battery got hot, do ya THINK ya might have damaged the rectifier diodes inside your counterfit regulator? And in turn, your regulator just MIGHT not be working properly?

I would suspect the "close but no cigar" counterfeit regulator before I suspected the counterfeit Chinese meter. I realize it's hard to find anything that isn't a cheap Chinese knockoff now days, but the meters are more accurate than one would think, since the counterfeit meter chips are pretty much standardized now days.

I tend to agree with the guys, that a fully charged new battery voltage is ~12.89 VDC fully charged, and charge voltage with the bike running and lights on should be enough to compensate for the lighting and the required current to power the ignition and accessories. (turn signals, brake lights etc)

1981 Kawasaki Kz1000K1
Located in the Saint Louis, Missouri Area.

Last edit: 02 Jul 2018 13:44 by old_kaw. Reason: more deep thoughts by jack handy :-)

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loudhvx
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Re: Charge Voltage

02 Jul 2018 13:25

#786298

The reg/rec was out of the picture when measuring the resting battery voltage, and it would have no way of making the battery reading high. That is why I am suggesting the meter should be verified.

1981 KZ550 D1 gpz.
Kz550 valve train warning.
Other links.

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old_kaw
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Re: Charge Voltage

02 Jul 2018 13:42

#786299

loudhvx wrote: The reg/rec was out of the picture when measuring the resting battery voltage, and it would have no way of making the battery reading high. That is why I am suggesting the meter should be verified.

Good point. I was not even considering this, and at this point any more suggestions seem to be confusing the OP. There is no way that a new battery, that is at a stabilized charge level (as if it was sitting overnight and the float charge level dissipated) would be over 12.9X volts.. unless of course the china men jammed a few more plates into that counterfeit battery. Also unlikely, since lead plates matter.

When a battery is hooked up backwards, the rectifier diodes in the alternator do not approve.

1981 Kawasaki Kz1000K1
Located in the Saint Louis, Missouri Area.

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gordone
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Re: Charge Voltage

02 Jul 2018 23:15

#786336

Sorry for my bad english, I was not able to cross wirer positive and negative... but I made a short circuit to earth from the battery direcly....
the positive pol was hitting the seat base for 5 seconds some times maybe... so the posititve and negative has not been swapped.

The short curcuit was not over the regulator, since the short curcuirt was from positive pol to earth it should only be the battery who was effected as I see it.

1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).

Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine

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Nessism
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Re: Charge Voltage

03 Jul 2018 07:20

#786346

Good news: if you are getting 15 VDC max. charging then your stator is good.

Bad news: 15 VDC is too high. Something is wrong with the R/R and/or your wiring (which is unlikely if you are wiring direct.)

Since the bike seems to be charging at 14.5 VDC max now then maybe everything is okay. If the charging climbs up to 15 V again then the R/R is bad.

Ed
Carb O-ring Kits : www.kzrider.com/forum/3-carburetor/61807...-o-ring-kits?start=0

www.kzrider.com/forum/faq-wiki/618026-new-owner-things-to-know

1981 KZ750E2
www.kzrider.com/forum/11-projects/604901...z750e-project-thread

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gordone
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Re: Charge Voltage

03 Jul 2018 07:37

#786349

Nessism wrote: Good news: if you are getting 15 VDC max. charging then your stator is good.

Bad news: 15 VDC is too high. Something is wrong with the R/R and/or your wiring (which is unlikely if you are wiring direct.)

Since the bike seems to be charging at 14.5 VDC max now then maybe everything is okay. If the charging climbs up to 15 V again then the R/R is bad.

Thank you for your clarifications, can bad battery do these also ?

Option:
Battery ?
Regulator?
Wiring?

1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).

Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine

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gordone
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Re: Charge Voltage

07 Jul 2018 15:35

#786587

I haven’t been able to borrow a multimeter yet...

I measured the battery after 4-5 days without charging and I got 13,09v

After a hour drive today I measured 13,75v after I killed the engine. Then I started it up and after some seconds I measured 14,40-14,44v on idle.

1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).

Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine

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