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#1020451 - 10/08/18 10:41 AM Charging Question  
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Rogerl Offline
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Rogerl  Offline
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Northfield, Ohio
I have a small volt meter on my 2013 R1200R. Typically when I am riding the bike the volt meter reads 14.0 to 14.1 volts. Over the last few weeks the meter has been reading 13.6 volts. I do not have the heated grip on or using the heated jacket. No extra lights were added. Nothing has been added to the bike. The battery is about 3 years old and it is on it's last legs. I am gong to replace the battery next spring. Is it just the battery that is causing the low charging voltage or is there a possible problem with the alternator. And information would be appreciated.


Thanks
Roger L

#1020456 - 10/08/18 11:45 AM Re: Charging Question [Re: Rogerl]  
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dirtrider Offline
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Originally Posted by Rogerl
I have a small volt meter on my 2013 R1200R. Typically when I am riding the bike the volt meter reads 14.0 to 14.1 volts. Over the last few weeks the meter has been reading 13.6 volts. I do not have the heated grip on or using the heated jacket. No extra lights were added. Nothing has been added to the bike. The battery is about 3 years old and it is on it's last legs. I am gong to replace the battery next spring. Is it just the battery that is causing the low charging voltage or is there a possible problem with the alternator. And information would be appreciated.


Thanks
Roger L


Morning Roger

Once started & running then the battery condition should not be effecting alternator charging voltage.

The BMW alternator/regulator is usually pretty stable so in your case I would first suspect that you have a problem with your on-bike voltmeter or have a problem with the voltmeter's connections.

Maybe put a good quality voltmeter on the battery posts to verify the true charging voltage.

Where is your add-on voltmeter picking up it's voltage input from?


D.R. ___
Sent from my rotory dial wall phone!
#1020477 - 10/08/18 04:09 PM Re: Charging Question [Re: dirtrider]  
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Rogerl Offline
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Rogerl  Offline
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Northfield, Ohio
Dirt Rider:
I need to look to see where the volt meter is connected. It has been a while since I installed it. I have a volt meter on my TPMS unit and it is reading close to the same voltage 12.5 volts. I will hook up another vole meter right to the battery and see what that reads.

Thanks
Roger L

#1020479 - 10/08/18 04:12 PM Re: Charging Question [Re: Rogerl]  
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dirtrider Offline
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Ohio
Originally Posted by Rogerl
Dirt Rider:
I need to look to see where the volt meter is connected. It has been a while since I installed it. I have a volt meter on my TPMS unit and it is reading close to the same voltage 12.5 volts. I will hook up another vole meter right to the battery and see what that reads.

Thanks
Roger L


Afternoon Roger

12.5 volts is a pretty dead battery.


D.R. ___
Sent from my rotory dial wall phone!
#1020506 - 10/09/18 12:35 AM Re: Charging Question [Re: Rogerl]  
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Rogerl Offline
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Northfield, Ohio
More Data.
The volt meter is hooked to the auxiliary fuse block under the seat. Tonight driving home from work the volt meter read 13.9 to 14.0 volts. When I got home and shut off the bike the voltage read 13.2 volts. I went inside changed cloths and came out and took off the seat. I connected my digital volt meter to the battery with the bike ignition switch off and the voltage was 13 volts. I turned on the ignition switch and the volt meter on the bike came on and it read 12.6 volts my volt meter hooked directly to the battery read 12.6 volts as well. I started the bike and both volt meters read 14.0 volts. I let the bike sit 3 hours and when I turned on the ignition to check the battery voltage it was 12.5 volts.
It looks like the volt meter on the bike is reading identical to my digital volt meter that I hooked to the battery. The temperature going to work this morning was 68 degrees F. Coming home the temperature was 86 degrees F. I will see what the volt meter on the bike reads driving into work tomorrow.

Roger L

#1020744 - 10/12/18 10:56 AM Re: Charging Question [Re: dirtrider]  
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Capt.Ret. Offline
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Raleigh, NC
Originally Posted by dirtrider
Originally Posted by Rogerl
Dirt Rider:
I need to look to see where the volt meter is connected. It has been a while since I installed it. I have a volt meter on my TPMS unit and it is reading close to the same voltage 12.5 volts. I will hook up another vole meter right to the battery and see what that reads.

Thanks
Roger L


Afternoon Roger

12.5 volts is a pretty dead battery.

Dirt Rider:
When you say 12.5 volts indicates a pretty dead battery, what should my voltage read if my MC is not running and not connected to a trickle charger. The voltage meter was installed by the previous owner and I don't have the knowledge to figure out where it is connected.

#1020745 - 10/12/18 11:14 AM Re: Charging Question [Re: Capt.Ret.]  
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dirtrider Offline
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Originally Posted by Capt.Ret[quote=Rogerl

Dirt Rider:
When you say 12.5 volts indicates a pretty dead battery, what should my voltage read if my MC is not running and not connected to a trickle charger. The voltage meter was installed by the previous owner and I don't have the knowledge to figure out where it is connected.


Morning Roger

It depends on: what type of battery (Gel or AGM), battery temperature, time since last charge or since last engine running.

At a nominal battery temp (not real hot or real cold) then most good condition fully charged AGM 12v batteries will show in the 12.7v-12.85v range.

At a nominal battery temp (not real hot or real cold) then most good condition fully charged Gel 12v batteries will show in the 12.8-12.85+v range.

The above voltages are for a direct battery post voltmeter connection. If the voltmeter connection is made to wiring in the vehicle harness, or post ignition switch, then it could be a tenth or more lower.

Static battery voltage is just a quick status, to really know battery condition it should have a proper load test.


D.R. ___
Sent from my rotory dial wall phone!
#1020807 - 10/13/18 11:42 AM Re: Charging Question [Re: dirtrider]  
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Capt.Ret. Offline
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Raleigh, NC
Dirtrider:

Well, I guess my battery is okay. I asked because when the engine is cold (been sitting overnight, trickle charger attached) it's slow to crank. I'm worried about going somewhere, park for several hours, and then not have enough juice to turn the engine over.

Thanks, and, by the way, I find your responses to others' inquiries to be very helpful. I rarely post, but often read.

Originally Posted by dirtrider
Originally Posted by Capt.Ret[quote=Rogerl

Dirt Rider:
When you say 12.5 volts indicates a pretty dead battery, what should my voltage read if my MC is not running and not connected to a trickle charger. The voltage meter was installed by the previous owner and I don't have the knowledge to figure out where it is connected.


Morning Roger

It depends on: what type of battery (Gel or AGM), battery temperature, time since last charge or since last engine running.

At a nominal battery temp (not real hot or real cold) then most good condition fully charged AGM 12v batteries will show in the 12.7v-12.85v range.

At a nominal battery temp (not real hot or real cold) then most good condition fully charged Gel 12v batteries will show in the 12.8-12.85+v range.

The above voltages are for a direct battery post voltmeter connection. If the voltmeter connection is made to wiring in the vehicle harness, or post ignition switch, then it could be a tenth or more lower.

Static battery voltage is just a quick status, to really know battery condition it should have a proper load test.



#1021521 - 10/24/18 11:05 PM Re: Charging Question [Re: Rogerl]  
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Posts: 140
Rogerl Offline
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Rogerl  Offline
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Northfield, Ohio
More Data:
I found out that if I turn off my front auxiliary lights the volt meter on the dash goes from 13.6 volts to 14.1 volts. Tonight riding home from work I left the auxiliary lights off and the volt meter on the dash stayed at 14.1 volts the entire way home. If I turned on the front lights the volt meter dropped to 13.6-13.7 volts.

The front auxiliary lights consist of (2) 7 watt LED lights and one set of Skene Photon Blaster lights. Doing the math the 7 watt LED lights should pull .58 amps each. From the published data on the Skene lights they should pull .35 amps. I took a clip on amp meter and disconnected both of the auxiliary lights and measured the current in the power wire to the front lights and it read .4 amps. very close to the specified current for the lights. I then hooked up one of the auxiliary lights and the current measured 1.1 amps . With both lights connected the current read 1.6 amps. which is very close to what amperage that they should be drawing. With a 1.6 amp load it is pulling 19.2 watts of power from the alternator.

Since this problem of the low voltage when riding has just started showing up I thought that maybe one of the front lights was going bad causing it to draw more current and pulling down the alternator. The measurements that I made do not show that. Does this show that the alternator is having problems? Could it be the wire connection to the alternator is corroded causing it to not supply power under load?

Any information would be great.

Thanks
Roger L

#1021523 - 10/24/18 11:36 PM Re: Charging Question [Re: Rogerl]  
Joined: Jun 2010
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dirtrider Offline
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dirtrider  Offline
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Posts: 14,633
Ohio
Originally Posted by Rogerl
More Data:
I found out that if I turn off my front auxiliary lights the volt meter on the dash goes from 13.6 volts to 14.1 volts. Tonight riding home from work I left the auxiliary lights off and the volt meter on the dash stayed at 14.1 volts the entire way home. If I turned on the front lights the volt meter dropped to 13.6-13.7 volts.

The front auxiliary lights consist of (2) 7 watt LED lights and one set of Skene Photon Blaster lights. Doing the math the 7 watt LED lights should pull .58 amps each. From the published data on the Skene lights they should pull .35 amps. I took a clip on amp meter and disconnected both of the auxiliary lights and measured the current in the power wire to the front lights and it read .4 amps. very close to the specified current for the lights. I then hooked up one of the auxiliary lights and the current measured 1.1 amps . With both lights connected the current read 1.6 amps. which is very close to what amperage that they should be drawing. With a 1.6 amp load it is pulling 19.2 watts of power from the alternator.

Since this problem of the low voltage when riding has just started showing up I thought that maybe one of the front lights was going bad causing it to draw more current and pulling down the alternator. The measurements that I made do not show that. Does this show that the alternator is having problems? Could it be the wire connection to the alternator is corroded causing it to not supply power under load?

Any information would be great.

Thanks
Roger L


Evening Roger

Difficult to tell much without further testing.

I guess before making any type of determination you should connect a precise voltmeter directly to the battery posts then ride the bike with the auxiliary lights on. The aux. lights could be lowering the system voltage due to load on the system wiring circuits but not really effecting charging or barratry voltage that much.

If the battery voltage is also low then probably check the alternator connections & maybe alternator output. Might also check the actual amperage that the aux light draw when hot & in use.


D.R. ___
Sent from my rotory dial wall phone!

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