82 GS1100EZ Charging at 15.63 Volts

[Muser3]

After replacing the Stator and R/R the bike runs and charges. The charging voltage I fear will cook my battery.
The battery is new and has been on a maintenance charger and consistently reads 12.63 volts. It spins the starter well and the system charges at 13.34 at warmup idle of around 3200 rpms. At 4500 rpms, it charges at 15.63 volts. I have used two different volt ohmmeters and they read the same. I rode the bike to town yesterday to have it inspected and it ran fine. Upon returning from the 20 mile round trip I felt for warm wires and found none. :-D (It was in the 70's here yesterday.) I have never had a vehicle with this kind oa charging voltage. Am I in danger of cooking the battery or melting insulation on wires etc? I like long rides and camping and I really don't think I can trust this situation in the summer heat. What do you think?
The Stator is from Electrosport and the R/R is one of those really cool Honda rebuilds from Duaneage.
Thanks,
Lee

 

[Jaguarjoe]

Check the voltage on the R/R's sense wire. If its below battery voltage it will cause the R/R to try and make up the difference overcharging your battery.

 

[Dave8338]

In my opinion...No. My bike charges slightly higher than the suggested 14.4V @ 4000+- and I've not experienced any problems with the battery cooking and have logged more than 2,000 miles this way. I think that mine is in the range of 15.4 and again, no problems. :?

 

[KiwiGS]

Check the voltage on the R/R's sense wire. If its below battery voltage it will cause the R/R to try and make up the difference overcharging your battery.

What he said and make sure all of your conections are sound as well (poor sense wire connection could reduce sensed voltage)
Cheers

 

[Muser3]

Hi v

Hi v

Thanks for those quick replies. I will check the voltage of the sense wire. It is a splice into the rear brake + feed. All of those new connectors were soldered before they were installed and dielectric grease was lightly applied. This GS is a completely new experience for me and I LOVE the beast! \\/
Lee

 

[earlfor]

A charging current of 15.4 is going to cause the battery to boil, shorten bulb life (headlight and tail) and will absolutely cause the death of an electronic ignition system.

Earl

In my opinion...No. My bike charges slightly higher than the suggested 14.4V @ 4000+- and I've not experienced any problems with the battery cooking and have logged more than 2,000 miles this way. I think that mine is in the range of 15.4 and again, no problems. :?

 

[Redman]

When you measure the voltage that the R/R is sencing (or measuring any voltage actaully) you must be be carfull to not only where you have the positive meter lead, but also where you place the negitive meter lead. In this case you want to measure what the R/R is sencing so put the positive lead where the R/R sence lead is AND put the negitive meter lead where the R/R negitive is. ANd by that I mean not just a ANY ground point, but where the R/R is connected to the ground. Better yet, put the negitive lead on the R/R case.

I say this because one reason for too high a charging voltage is that the R/R is not well grounded. If the R/R isnt well grounded, but you put the meter negitive lead to something that is well grounded, well, then your meter reading is not what the R/R is seeing.

If you dont want to understand all that.... just do this first.
With engine running: Measure voltage between the R/R case and frame ground, should be about zero (or just a small fraction of a volt). Measure voltage between R/R case and battery negitive, should be about zero also. BOth should about zero volts, because R/R should be well grounded, so those 3 things should all be connected together so all at same voltage. If R/R is not well groaunded, then the R/R will overcharge for two reasons.
.

 

[Guest]

When you measure the voltage that the R/R is sencing (or measuring any voltage actaully) you must be be carfull to not only where you have the positive meter lead, but also where you place the negitive meter lead. In this case you want to measure what the R/R is sencing so put the positive lead where the R/R sence lead is AND put the negitive meter lead where the R/R negitive is. ANd by that I mean not just a ANY ground point, but where the R/R is connected to the ground. Better yet, put the negitive lead on the R/R case.

I say this because one reason for too high a charging voltage is that the R/R is not well grounded. If the R/R isnt well grounded, but you put the meter negitive lead to something that is well grounded, well, then your meter reading is not what the R/R is seeing.

If you dont want to understand all that.... just do this first.
With engine running: Measure voltage between the R/R case and frame ground, should be about zero (or just a small fraction of a volt). Measure voltage between R/R case and battery negitive, should be about zero also. BOth should about zero volts, because R/R should be well grounded, so those 3 things should all be connected together so all at same voltage. If R/R is not well groaunded, then the R/R will overcharge for two reasons.
.

Excellent post. I learned something that actually makes sense to my subpar electrical knowledge.

 

[Muser3]

HiV

HiV

Thanks for those posts. The negative lead of the R/R connects the the negative battery terminal. The Positive lead is fused and connected to the Positive Battery terminal. I will compare the R/R case to the Ground and the sense wire voltage to the battery voltage.
I must tell you guys that this sharing of information and real concern is just too cool. :-D Please hang with me until this gets resolved.
Thanks,
Lee

 

[Redman]

What you find Muser?

Usally the R/R negitive is "grounded", but usally "grounded" to battery box, but then sometimes the battery box isnt very well grounded so therefor the R/R isnt well grounded. That is why you will hear recommendations to run wire directly from R/R negitive to battery negitive, and apparently someone has done that.
But still measure from R/R sence (where ever that is) to R/R negitive (where ever that is). Should be same as you read of battery positive to battery negitive. If its not, then the R/R aint measuring what it is suppose to be controlling, so how can it controll what it isnt measuring (dont mean to get phylosophicall har har har).

Get that thing running. Then look in Meeting Place forumn for the Texas Hill Country ride (in spring and fall).

.

 

[Muser3]

HiV

HiV

I think I 'm screwed!!
I ran a ground wire to the case from the neg. batt. terminal. No difference. Then my brake bulb burned out. Then after I replaced it with a 1157 which is all I have today, the charging voltage dropped from 16 to just under 13 volts. That is too low.
I've been playing with this all day off and on and the sense voltage is still 1 to 1.3 volts below the battery voltage while running.
I ride the hill country often. My sons and I did a week in May from the Dallas area to the Big Bend to Del Rio and Mexico and back up through the Hill Country. Took 7 days of riding and camping out. Total blast!!
I thought I posted this an hour or so ago, but it's not here. Probably on some other thread. Or maybe i just deleted it or whatever. I'm not too swift on these new-fangled gadgets.
Maybe you can give me an idea or two.
Thanks,
Lee

 

[earlfor]

Its possible the bulb was shorting and causing the high charge rate.
For what its worth, I had installed for the last three years I owned it, a voltage meter on my 1150 dash. When the battery was in a fully charged state, the normal voltage reading in the electrical system was 13.1 to 13.2 volts when I was cruising down the highway at 65 mph. If your charging system was overcharging, I think it likely your battery is fully charged and consequently the charge rate will/should be at its lowest. You didnt say what rpm you are getting 13 volts at. Its a little low for a cruising rpm of 4k, but its plenty high if you checked at idle rpm or slightly above. I would check battery voltage with the bike not running and everything off. If the battery is fully charged, it should show somewhere between 12.7 and 13 depending on age/condition of the battery. If the battery is fully charged, a charge rate of near 13v or so is normal. If the battery is discharged (hovering around 12v) then a charging rate of 13 is marginal.

Earl

I think I 'm screwed!!
I ran a ground wire to the case from the neg. batt. terminal. No difference. Then my brake bulb burned out. Then after I replaced it with a 1157 which is all I have today, the charging voltage dropped from 16 to just under 13 volts. That is too low.
I've been playing with this all day off and on and the sense voltage is still 1 to 1.3 volts below the battery voltage while running.
I ride the hill country often. My sons and I did a week in May from the Dallas area to the Big Bend to Del Rio and Mexico and back up through the Hill Country. Took 7 days of riding and camping out. Total blast!!
I thought I posted this an hour or so ago, but it's not here. Probably on some other thread. Or maybe i just deleted it or whatever. I'm not too swift on these new-fangled gadgets.
Maybe you can give me an idea or two.
Thanks,
Lee

 

[Guest]

My battery reads 12.8 not running and 13 and rising at 3000 RPMs. What does the battery read without running? This will affect the charging at idle. Mine actually drops a little. But at 4000 RPMs I'm at 14.9 but never over 15.

My batterys a couple of years old and was ran with a bad R/R for most of the that time. I too have a Honda R/R.

 

[Muser3]

Hi V

Hi V

Thanks, That's good info for me. The voltage of the battery is 12.63. If I keep connected to a maintenance charger it will hover around 12.9. So therefore if I do not need a lot of charge, 12.9 or 13 is good, right? So if I leave the key on for a while and deplete the battery down to ll.5 volts or so the charge rate should rise to over 13.5 or so? Might be something to try .
About the bulb-- could it be shorting and still be working properly? I just took the bike into town and had the mandatory safety inspection done and the tail and brake light were working then. I'm still puzzled, but then I've been puzzled for most of my life about one thing or another.
Thanks for the help.
Lee

 

[Guest]

You battery is at 12.63 fully charged?

 

[Muser3]

Hi V

Hi V

Yep! That's after several minutes at many different times charging at 15-16 volts. And after a 20 mile round trip to get the bike's safety inspection that's required here in Tx.
It's a two week old battery.
I'm just now getting the bike running. As soon as I figure how, I will post some pics of a scruffy, rusted, mouse and rat knawed, peed and pooped on pitiful excuse for a bike. She's got her dignity back now and she Rocks!!
Now all I've gotta do is get these details worked out.
Thanks,
Lee

 

[Suzuki_Don]

How long should a battery hold its charge when the bike is not being used. Should it last for a month without being used and still start off the starter motor. My battery is new and to me it does not seem to last as long as it should. Maybe it is discharging when not in use. Anyone have any input.

Cheers

Don

 

[earlfor]

A battery that holds a charge level of 12.63 after coming off a battery charger and initially showing 13 volts is a bad battery. If your charging system has been charging in excess of 15 volts, the first thing I would do is check the water level in the battery. It may have boiled half dry. At least add water to bring it back to the full line. I would replace it though.

The correct rate to set your battery charger to is 2 amps output for a motorcycle battery. Rate should be 10% of capacity. Motorcycle batteries (for GS's) are usually 10 to 12 amp, so a rate of 1 to 1.2 amps would be correct, but most chargers have a lowest rate of 2 amps. usually you will have to charge a 12 amp motorcycle battery at a 2 amp rate for 7 1/2 hours to net 12 amps. The rest is lost due to inefficiency of the process.
After charging, and removing the charger, let the battery sit overnight and then check the voltage level on the battery. That reading is what the charge holding potential of your battery is. If its less than 12.6-12.7, its ready for the trash pile. Personally, I discard any battery that will not hold 12.8 overnight.

Earl

Yep! That's after several minutes at many different times charging at 15-16 volts. And after a 20 mile round trip to get the bike's safety inspection that's required here in Tx.
It's a two week old battery.
I'm just now getting the bike running. As soon as I figure how, I will post some pics of a scruffy, rusted, mouse and rat knawed, peed and pooped on pitiful excuse for a bike. She's got her dignity back now and she Rocks!!
Now all I've gotta do is get these details worked out.
Thanks,
Lee

 

[earlfor]

I see about a 1/10v drop in a month on a fully charged battery not in use. I'm using sealed, glass mat batteries though. I wouldnt think a lead acid type would lose more than .2v per month.

Earl

How long should a battery hold its charge when the bike is not being used. Should it last for a month without being used and still start off the starter motor. My battery is new and to me it does not seem to last as long as it should. Maybe it is discharging when not in use. Anyone have any input.

Cheers

Don

 

[Suzuki_Don]

Thanks Earl