Low charge rate with lights on

[JTGS850GL]

A shunt regulator is a specific design rectifier/regulator that was very common for the period and still used on some bikes today. Basically it "shunted" any unused current back into the stator winding. This had the tendency to generate a lot of heat and eventually fry the stator. If yours does not say SH-775 on it then it's more then likely a shunt type regulator.

 

[posplayr]

well, where to start, since you ask? ....and I wouldn't say "without merit" or "erroneous" given my assumption that somebody must have get these readings- just not me. I haven't discerned any reason why I need these same readings either. But that said, the trend is ok.
Quick Test Steps:

1.) key off................Normal 12.7 volts-12.9 volts I dont have any bike that does this. 12.5+ is good to go on a resting wet battery ,IMO.

2.) key on (but not cranking with lights for 10 sec).....Normal 12.2-12.5 volts uh,uh. I think Not on any bike I have, given this says headlamp and tail light are ON for 10 seconds . Perhaps the average temperature in Canada has an effect on this, but I don't have any 12-14 ah batterries that can display so near what my "resting voltage" is when they have 40+ watts load. But the batteries down there must be different, apparently Always reading 2-4 tenths higher to start.

3.) at idle (1500 rpm).....12.6volts - 13.2volts mmm. without an exact rpm match(mine is lower on 3/4) I still will offer....= 14.2 or more on 2/4 bikes...the other 2/4 bikes do show voltage very similar to what is shown 12.6-13.2) even at lower rpm and even with headlamp on. Brakelight and turn signals will lower vdc on these though. On the 400, displayed voltage can be easily be less than 12.0 at a stoplight with signals and brakelight on. But my rpm is less too.

4.) at 2500 rpm 13.5 -14.0 volts "I dunno". No consequence to me. I never bother specifically and don't ride at this rpm at all.

5.) at 5000 rpm.....14.0 -15.0 volts yes on 2/4 ... but say, 13.5 to 13.8 on the other two with headlamp( lo beam) and tailight on.

6.) key off.....slightly higher than measurements # 1 (12.8-13.0 v) ....for a short while ...not something I worry about unless it's below the original "key-off" =12.5+

I lost my response but is was basically about low battery voltage. here is some text from the Quick test referring to the provided link.

P.S. The voltages are indicative of state of charge as described in the file below. There are some variations in voltage but the shape of the curves is pretty representative.

http://www.scubaengineer.com/documents/lead_acid_battery_charging_graphs.pdf


Rule of thumb C/10 would have the R/R output set at 14.V/100% SOC which is pretty typical. The Suzuki R/R's are pretty loosey goosey with an upper allowable range of 15.5V IIRC.

Anyway, this is really relatively independent of the at rest battery voltage which is not really even given in the curves as they assume at least C/100 Charge / Discharge and there is a significant discontinuity there.

Taking a closer look at the last chart is showing 12.7V at C/100 discharge and 13.35 ish at C/40 charging. So the lower chart confirms voltages in high 12's even possibly over 13V for topped off batteries.

So immediately after a ride if you are are at 12.5V I would say you are probably not charging very well

.

 

[suzukizone]

A shunt regulator is a specific design rectifier/regulator that was very common for the period and still used on some bikes today. Basically it "shunted" any unused current back into the stator winding. This had the tendency to generate a lot of heat and eventually fry the stator. If yours does not say SH-775 on it then it's more then likely a shunt type regulator.

OK, Thanks for the clarification there. I probably should know that but must have cut class that year!

I can't find the specifics as to what I got, installed it back in March 2012. I know it was one of the Honda R/Rs that were touted here on GSR forum but closest my memory does is CB(R?)900?????? (Surprised I don't have the info as I try to write this kind of info in my repair "diary" but all I got is the date.)

Going through the checklist right now, will post results when I'm all done in a dropbox folder so won't bore anyone unless I have a question or anyone out there is so bored that those detail would entertain.

Negative results show up on the initial battery quick steps test except for the key off battery reads which were better than specs. One coil had real low output, other 2 were 70 v & 90 v if I did it right with 1 at 20 v.

Thanks again, I'm learning but with my brain, I must write it down or I'll forget more than I learned.

DH

 

[wymple]

I understand your point, but to me bike is worth about 50 grand. To you, the bike would look like crap, not clean, weird **** hanging off, oil leaks, the world's strangest fixes, scraps, scratches & scars. But every time I walk up to Roadkill, I always say to myself,.."Man what a beautiful bike!." Just because Donald Trump feels the need to keep trading in spouses every few years for a newer model, don't mean that some of us love our old babes to death. Not to be offensive, but there are many kinds of beauty and value. If not would wart hogs be able to reproduce with out poking their eyes out first? Wow, how zen is that?

BTW, it is possible that Roadkill has up to 170k as she looked like **** when I got her used with 20k on the speedo but many many signs that 20k might have been a whole lot more. She has broken so many speedo cables, speedo drives and speedos that I know use a SIGMA bike speedo & love it.

DH

Well, now that you've cleared that up, I'd say go for it. You have reason to ignore the cost/benefit ratio of an old bike. I have 2 like that. I got my old 850 from my son so it's worth far more to me than to anyone else. So when it becomes necessary I will do whatever it takes. There is damn little original to the bike as I have tagged TWO deer with it. I don't even know what the tach is off from, the rear rack is homemade, the seat (for my butt) is from a Yamaha venture. I made the mounting structure for the Windjammer. I will ride it as long as the battery stays up, then ride my other DD while I fix it.

 

[Gorminrider]

I lost my response but is was basically about low battery voltage. here is some text from the Quick test referring to the provided link.


P.S. The voltages are indicative of state of charge as described in the file below. There are some variations in voltage but the shape of the curves is pretty representative.

http://www.scubaengineer.com/documen...ing_graphs.pdf


Rule of thumb C/10 would have the R/R output set at 14.V/100% SOC which is pretty typical. The Suzuki R/R's are pretty loosey goosey with an upper allowable range of 15.5V IIRC.

Anyway, this is really relatively independent of the at rest battery voltage which is not really even given in the curves as they assume at least C/100 Charge / Discharge and there is a significant discontinuity there.

Taking a closer look at the last chart is showing 12.7V at C/100 discharge and 13.35 ish at C/40 charging. So the lower chart confirms voltages in high 12's even possibly over 13V for topped off batteries.

So immediately after a ride if you are are at 12.5V I would say you are probably not charging very well

...well, I think they all work fine. As I said, I don't care what it says after a ride as long as it's not less than I started with, because it's a very transitory reading then. also, "12.5+" is >12.50.... 12.57 on one I just turned on according to the little VM on it...

I have plenty of battery charts already.
No battery is brand new for long.Especially cheapo MC batteries. They have limited cycles. If any ever read 12.65 I can't remember it! Not for long anyways. 12.57 would be @ 85% or so? according to a chart that needs temperature measured and also states plate composition is a factor and that voltage is not the best indicator anyways? ....The hydrometer read in the green for all a month ago. After more than a year of use and or just sitting, that does not indicate a charging problem to me.

Not to say you are wrong. YOU asked for an example and I am giving one. Perhaps meeting these high standards to the second decimal on a 35 year old motorcyle every day is not really "trouble-shooting" as I experience it. merely a difference of philosophy.... Looking at the example(per Quick Charging) makes no broad sense to my real case in the beginning - my ADD kicks in. You can refer me to a ton of documents but what I would care about in a "quick test" is getting the battery to "Charge" so the bike will "Start" after a period of not running. Getting a new battery is a good thing, but fixing the charging with a 3/4 or half charged battery is also a possibility.

 

[Nessism]

I helped a member here install a new R/R on his 750 and best we could do was 13.7 volts or so. He didn't have money for a new stator and said he'll just monitor the situation closely and get back in contact if there were any running issues, only I haven't heard from him since. One other thing, if the stator power is low there won't be much extra current to shunt back to the stator thus you don't need to worry about that sort of deterioration.

 

[posplayr]

...well, I think they all work fine. As I said, I don't care what it says after a ride as long as it's not less than I started with, because it's a very transitory reading then. also, "12.5+" is >12.50.... 12.57 on one I just turned on according to the little VM on it...

I have plenty of battery charts already.
No battery is brand new for long.Especially cheapo MC batteries. They have limited cycles. If any ever read 12.65 I can't remember it! Not for long anyways. 12.57 would be @ 85% or so? according to a chart that needs temperature measured and also states plate composition is a factor and that voltage is not the best indicator anyways? ....The hydrometer read in the green for all a month ago. After more than a year of use and or just sitting, that does not indicate a charging problem to me.

Not to say you are wrong. YOU asked for an example and I am giving one. Perhaps meeting these high standards to the second decimal on a 35 year old motorcyle every day is not really "trouble-shooting" as I experience it. merely a difference of philosophy.... Looking at the example(per Quick Charging) makes no broad sense to my real case in the beginning - my ADD kicks in. You can refer me to a ton of documents but what I would care about in a "quick test" is getting the battery to "Charge" so the bike will "Start" after a period of not running. Getting a new battery is a good thing, but fixing the charging with a 3/4 or half charged battery is also a possibility.

Well I did ask you to be more specific about your broad swipe at technical info on teh GSR you made earlier in the thread. Thank you; you have made it clearer.

With respect to the battery voltages, the reason I referred you to the battery charts was to point out (perhaps you had missed it ) that the descriptions in the Quick Test tried to make the point that while battery voltage is very important there are variation due to various factors including temperature. The Quick Tests voltages seems to be written around the nominal battery voltages in the charts. This is instructive to the reader as they then should understand what the intent of the Quick Test is and should know better how to make adjustments as required depending on the variety of factors that affect the voltage. In your case it is largely temperature and you should make appropriate adjustments down in voltage to reflect your lower temperatures.

Further to you comments of the usefulness or purpose of the Quick test; for some reason reading your various responses you seem to think that the Quick Test is a battery test?

The QT does has a specific set of objectives which are largely to do with diagnosing a charging system. The diagnosis is to determine if there is a charging system problem and where it might lie or at least be a way to determine the approach to a second phase of more detailed testing. Basically is there and what is indicated about issues with battery, R/R, stator or wiring. It is not a "pre flight" check that you seem to be suggesting you see more value in. The Quick tests purports to give someone the ability be able to walk up to a bike of generally known condition and in 3 minutes (using just a voltmeter) give a clue as to the operational state of the various components of the system.

I would have to agree, there are distinct difference in the way I treat integrated diagnostics and the way you do.

 

[posplayr]

I helped a member here install a new R/R on his 750 and best we could do was 13.7 volts or so. He didn't have money for a new stator and said he'll just monitor the situation closely and get back in contact if there were any running issues, only I haven't heard from him since. One other thing, if the stator power is low there won't be much extra current to shunt back to the stator thus you don't need to worry about that sort of deterioration.

Ed in using the Quick Test in combination with the Stator Pages, a 13.7V reading at 5K RPM would be 0.5-0.7V low (corresponding to a 14.25-14.5V R/R reference independent of the battery). A quick check in Phase A of voltage drops would have indicated whether this was due to bad connections. In the absence of voltage drops the conclusion would have to be that the stator is failing. In either case your friend is living on "borrowed time".

Just because you never heard from him again does not mean that he never had a changing system failure any more than the fact that you never heard from him again means he never needed any further maintenance of his bike.

 

[Nessism]

Ed in using the Quick Test in combination with the Stator Pages, a 13.7V reading at 5K RPM would be 0.5-0.7V low (corresponding to a 14.25-14.5V R/R reference independent of the battery). A quick check in Phase A of voltage drops would have indicated whether this was due to bad connections. In the absence of voltage drops the conclusion would have to be that the stator is failing. In either case your friend is living on "borrowed time".

Just because you never heard from him again does not mean that he never had a changing system failure any more than the fact that you never heard from him again means he never needed any further maintenance of his bike.

There was no losses in the connections, the stator was just weak. Borrowed time? Maybe. The point is that 13.7 volts will get you down the road at least half way decently, and maybe even long term. We had this same discussion on KZ Rider and some of the members there said their charging systems put out similar voltage and they have been riding for YEARS like that.

As you have taught us all here at GSR, a Series R/R eliminates excessive charging system current from being shunted back to the R/R. But in the case where the charging system isn't producing much if any excess current that's a moot point. I believe that is the reason why Kawasaki KZ bikes don't have anywhere near the same number of issues with stator failure compared to Suzuki GS's. There is an incremental difference in the total charging system output, KZ bikes being slightly lower, and said output is a better match for the bikes needs than a GS's.

At any rate, a slightly weak stator can often get the bike down the road for some time. Mid 13 volt range isn't the worst thing imaginable. Might be a good idea to ride with the headlamp off where possible to boost that a little. Or throw the battery on a charger every other week or so. To each their own.

 

[suzukizone]

Well, now that you've cleared that up, I'd say go for it. You have reason to ignore the cost/benefit ratio of an old bike. I have 2 like that. I got my old 850 from my son so it's worth far more to me than to anyone else. So when it becomes necessary I will do whatever it takes. There is damn little original to the bike as I have tagged TWO deer with it. I don't even know what the tach is off from, the rear rack is homemade, the seat (for my butt) is from a Yamaha venture. I made the mounting structure for the Windjammer. I will ride it as long as the battery stays up, then ride my other DD while I fix it.

Sounds like you're riding Roadkill's cousin! Keep 'er goin'

DH

 

[posplayr]

I think the direction this thread is heading has nothing to do with the OP's original problem .

He needs to be focused on the stator tests as his stator is likely going out, especially the leg to ground tests.

If there are any "non-mute" points you want to make about the Quick Tests , post them to that thread.

 

[suzukizone]

Just wanted to thank all of you who have helped me with this thread and the others I posted regarding Roadkill's charging syste,. I have ordered a new Polaris SH775BA & about to order a Caltric stator. Since you got me to this point, anyone want to buy any of my organs or other body parts to fund this process? Just spent a load on my car, upgrading of the propane system in the house, dental work, need new stove, and wife spent about 3 millino bucks on trees, plants, flowers etc. Now living on cardboard and dehydrated water for awhile.

THANKS!!!!
DH

 

[JTGS850GL]

Glad you've got things moving along with the bike. Just an FYI... Cut and past responses across multiple posts not so good.