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R100 Charging Problem
- Thread starter arptra
- Start date
Where do these readings come from? Voltmeter plugged into the bike's harness? Generally inaccurate readings. Try to do the same thing with a known good multimeter attached to the battery terminals and the meter taped to the tank (blue painter's tape) or stuck in a tank bag. Likely you're getting ground fluctuations on the stock meter.
Charging problem or bad battery . . .?
My '93 R100RT usually reads about 13.8 on the voltmeter when running along at any speed above an idle. Yesterday (a 75 degree day) the voltage showed 13 at speed and dropped below 12 at idle. Is the alternator the problem or my 4 year old gel battery?
Thanks,
Campbell Tellman II
My '93 R100RT usually reads about 13.8 on the voltmeter when running along at any speed above an idle. Yesterday (a 75 degree day) the voltage showed 13 at speed and dropped below 12 at idle. Is the alternator the problem or my 4 year old gel battery?
Thanks,
Campbell Tellman II
bikerfish1100
New member
CT- just as likely that the issue is your factory voltmeter is wonky. "they all do that". test the system with an external unit that is known to be good.
I forgot to add . . . . .
It wouldn't start this morning. Good oil, charge and neutral light but click, click, and click.
I am probably going to replace OEM alternator w/ Motorrad Elektric system. I have been concerned about a electric failure leaving me stranded as I commute every day on my airhead.
Thanks,
Campbell Tellman II
It wouldn't start this morning. Good oil, charge and neutral light but click, click, and click.
I am probably going to replace OEM alternator w/ Motorrad Elektric system. I have been concerned about a electric failure leaving me stranded as I commute every day on my airhead.
Thanks,
Campbell Tellman II
D
doktortim
Guest
Before spending money, spend the time to verify both ends of both batt cables for clean and tight, then go inside the front cover and verify same for all the system terminals. Then add an aux ground harness linking the alt housing, diode board timing cover and engine block.
Verify while in there the brush lengths and spring tension and that the brushes move freely up and down in the holder. Also do the ohms test of the rotor.
Now you can verify just what is happening at the batt terms directly.
The stock VDO voltmeters can sure go south. Mine dropped a full volt like overnight, and multimeter proved it bad. The gen light is far more reliable.
Ensuring proper system connnections and the added grounds jumped me from 13.5 to 14.0 volts. That is no small improvement.
And before doing anything above, verify the batt will take a full charge and will rebound nicely from a load test, independant of the bike systems.
Verify while in there the brush lengths and spring tension and that the brushes move freely up and down in the holder. Also do the ohms test of the rotor.
Now you can verify just what is happening at the batt terms directly.
The stock VDO voltmeters can sure go south. Mine dropped a full volt like overnight, and multimeter proved it bad. The gen light is far more reliable.
Ensuring proper system connnections and the added grounds jumped me from 13.5 to 14.0 volts. That is no small improvement.
And before doing anything above, verify the batt will take a full charge and will rebound nicely from a load test, independant of the bike systems.
Seems premature to me to jump to buy a new alternator. How old is the battery? Have you had it tested? Likely all you need is a new battery.
I have to check things out . . . .
This AM is the first time I have ever had an airhead fail to start. I was suspicious yesterday when the voltage dropped. It could be a bad connection. I will charge the battery and start to see.
Thanks you all for your input. I can wrench pretty well but I have some problems with electricity.
Campbell Tellman II
This AM is the first time I have ever had an airhead fail to start. I was suspicious yesterday when the voltage dropped. It could be a bad connection. I will charge the battery and start to see.
Thanks you all for your input. I can wrench pretty well but I have some problems with electricity.
Campbell Tellman II
amiles
New member
My 83 Charges fine about 13.5 at 60 mph but at 70 it drops back down to 11.5. Does anyone have an idea of what the problem is? Also willing to hear upgrade ideas but I really don't want to spend the 500.00.
Reply With Quote
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I can't argue with your being unwilling to part with the $500.00. Just keep in the back of your mind each time that you need to replace components or have a failure that this money could be a sort of a "down payment" towards the $500.00 sum. These days adding supplemental electrics (bright lights in particular) to the machines is like an irresistible force. I installed an Enduralast last year & haven't looked back, I really like having my battery "right up to snuff" somehow it increases my confidence.
With the Enduralast The "old wiring harness (alt to regulator to diode board) is replaced. My old wiring looked a little dated & dried out, I felt it a big plus to not use it anymore. Perhaps just changing this out or at least cleaning it's connections would be helpful to you..
I suspect that the replacement systems keeping the battery at a closer to ideal voltage might tend to prolong battery life, more so than the up & down characteristic I saw with the stock system backed up by a smart battery charger. For what it's worth I am a fan of & continue to use the ancient lead acid battery, not the newer varieties.
I'm sure if I am wrong someone might kindly point it out to me.
Reply With Quote
////////////////////////////////////
I can't argue with your being unwilling to part with the $500.00. Just keep in the back of your mind each time that you need to replace components or have a failure that this money could be a sort of a "down payment" towards the $500.00 sum. These days adding supplemental electrics (bright lights in particular) to the machines is like an irresistible force. I installed an Enduralast last year & haven't looked back, I really like having my battery "right up to snuff" somehow it increases my confidence.
With the Enduralast The "old wiring harness (alt to regulator to diode board) is replaced. My old wiring looked a little dated & dried out, I felt it a big plus to not use it anymore. Perhaps just changing this out or at least cleaning it's connections would be helpful to you..
I suspect that the replacement systems keeping the battery at a closer to ideal voltage might tend to prolong battery life, more so than the up & down characteristic I saw with the stock system backed up by a smart battery charger. For what it's worth I am a fan of & continue to use the ancient lead acid battery, not the newer varieties.
I'm sure if I am wrong someone might kindly point it out to me.
R100 Charging
I just came in from riding and the generator light was staying on at any speed, changed regulator with a used one I had and tested and at 3k it is 12.5 and sometimes jumping up to 14-16 and back down to 12.5 and this was with speed consistent , never less than 12.5 with the new/used regulator.
I have a new thunderchild diode board may install.
I just came in from riding and the generator light was staying on at any speed, changed regulator with a used one I had and tested and at 3k it is 12.5 and sometimes jumping up to 14-16 and back down to 12.5 and this was with speed consistent , never less than 12.5 with the new/used regulator.
I have a new thunderchild diode board may install.
You should use a methodical process to isolate the problem. Snowbum discusses troubleshooting here:
http://bmwmotorcycletech.info/trbleshootALT.htm
Motorrad Elektrik has a book that is a must for Airhead owners...pretty inexpensive; top of this page:
http://www.motoelekt.com/goodstuff.htm
http://bmwmotorcycletech.info/trbleshootALT.htm
Motorrad Elektrik has a book that is a must for Airhead owners...pretty inexpensive; top of this page:
http://www.motoelekt.com/goodstuff.htm
glad you found the problem... normal charging range is 13.8 to 14.2v
motorrad elektrik also offers a 14.5v regulator should you want to increase voltage range.
your alternator will not put out any more watts, but those amps will be delivered at higher volts. pushing more current into battery before cut off.
currently using a 14.5v regulator from motorrad elektrik to better mate to lithium ion (LiFePO4) batteries that I'm testing.
now that your system is hopefully charging correctly again. charge your battery full with a battery charger. allowing alternator to charge battery up from dead could risk overloading an already weak alternator (280 watts)
much kinder to your low watt charging system by only requiring it to top charge up vs charging battery from dead.
a good way to check out your meter: go to a HVAC supply that stocks Fluke 87V meters. take a 3v lithium battery for a stable test source to check your old meter.
here's my Martel MC-1000 putting 1.2v test volt. Fluke 87V and Fluke 16 shows calibration is within spec's.
motorrad elektrik also offers a 14.5v regulator should you want to increase voltage range.
your alternator will not put out any more watts, but those amps will be delivered at higher volts. pushing more current into battery before cut off.
currently using a 14.5v regulator from motorrad elektrik to better mate to lithium ion (LiFePO4) batteries that I'm testing.
now that your system is hopefully charging correctly again. charge your battery full with a battery charger. allowing alternator to charge battery up from dead could risk overloading an already weak alternator (280 watts)
much kinder to your low watt charging system by only requiring it to top charge up vs charging battery from dead.
a good way to check out your meter: go to a HVAC supply that stocks Fluke 87V meters. take a 3v lithium battery for a stable test source to check your old meter.
here's my Martel MC-1000 putting 1.2v test volt. Fluke 87V and Fluke 16 shows calibration is within spec's.
