FYI -12 Volts is not 12 Volts!! - Steve Saunders Goldwing Forums

Closed Thread
 
LinkBack Thread Tools
post #1 of 46 (permalink) Old 04-20-2011, 11:58 AM Thread Starter
Member
 
VTBikeman's Avatar
 
Join Date: Aug 2009
Location: Brattleboro, Vermont, USA
Year: 1989
Make: Honda
Model: GL1500
Posts: 212
Post imported post

FYI

I keep seeing people figuring their power use on bikes based on 12 volts average voltage. I want to alert anyone who is interested that this is important on bikes or any electrical system that is not rated for high power and you are drawing a load at or near the maximum rating.

The motorcycle and cars using lead acid batteries charging nominally at 14 volts. This may vary by bike and temperature a battery charging is affected by temperature and compensation for that may or may not be built in. But for the purposes of figuring power available for accessories the correct voltage to use is 14 volts.

Formula for power is P= EI i.e. Power = Volts (E) X Current (I)

Something that draws 10 amps uses 140 watts, not 120 watts. This can be significant for the GL1200 owners and other owners of bikes that have smaller alternators. This is about a 12% difference.

Why is this important? Because heating is directly related to the square of the current. P=I squared X Resistance (R). Double the current, quadruple the heat lost in wiring, especially the stator.

Many alternators are rated in watts. This is where it is important to use the right voltage to figure current when you need to think in amps rather than watts or you will be thinking you can draw more current than is really available.

89 GL1500 111+K (not my 111+k, yet!)
86 Honda Elite 250 -3k miles

Past fun:
85 Suzuki 450
86 Honda VT 500
84 Interstate
1980 Panasonic Bicycle with 50 cc motor

Nothing in all the world is more dangerous than sincere ignorance and conscientious stupidity. - MLK, Jr. 1963
VTBikeman is offline  
Sponsored Links
Advertisement
 
post #2 of 46 (permalink) Old 04-20-2011, 12:11 PM
Senior Member
 
ceasefire49's Avatar
 
Join Date: Oct 2009
Location: Florence, Arizona, USA
Year: 1984
Make: Goldwing Interstate 1200
Model: 1984 1200 I with many add ons
Posts: 1,093
Post imported post

Good info.Before I digest this though I think I will have a drinkThen I'll go back and figure out what it means. I think what you are saying is that guys like me that keep adding stuff to the bike really need to think about the Poor Boy conversion which I am going to do most rickety tic
Before we fry the little Pulse capacitor dealy located at the back of the engine that provides charging and maybe something else unpleasant and that would require lots of head scratching and posting all types of pleas for help here on the forum and that folks like you would have to solve..Hope you see the humor here.Because I am one of those guys that will be asking for your help.

Never argue with an idiot. They will only bring you down to their level and beat you with experience every time.
ceasefire49 is offline  
post #3 of 46 (permalink) Old 04-20-2011, 12:25 PM
Senior Member
 
Join Date: May 2009
Location: Escondido, California, USA
Posts: 909
Post imported post

From the conscientiously stoopid, I'm having a hard time figgerin' yer point. Help me out bro. Whadda I gotta look out for?
escogold is offline  
Sponsored Links
Advertisement
 
post #4 of 46 (permalink) Old 04-20-2011, 12:32 PM Thread Starter
Member
 
VTBikeman's Avatar
 
Join Date: Aug 2009
Location: Brattleboro, Vermont, USA
Year: 1989
Make: Honda
Model: GL1500
Posts: 212
Post imported post

Enjoy your beverage!

Think of it this way. Your headlight dims when the engine idles at low RPM and is not charging the battery. System voltage drops to battery voltage, around 12.6 volts, because it is not charging. In order for the battery to charge the system voltage needs to be at around 14 volts +/- .2 volts.

Like for water to fill a tank there has to be enough water pressure to raise the water above the level of the water in the tank.

Analogies -

Water to Electric
Pressure = Voltage
Crimp in the hose or partially closed valve or skinny pipes = resistance (anything that gets warm)
Flow - gallons/ second = current


Hope this helps.

89 GL1500 111+K (not my 111+k, yet!)
86 Honda Elite 250 -3k miles

Past fun:
85 Suzuki 450
86 Honda VT 500
84 Interstate
1980 Panasonic Bicycle with 50 cc motor

Nothing in all the world is more dangerous than sincere ignorance and conscientious stupidity. - MLK, Jr. 1963
VTBikeman is offline  
post #5 of 46 (permalink) Old 04-20-2011, 12:45 PM
Senior Member
 
Join Date: May 2009
Location: Escondido, California, USA
Posts: 909
Post imported post

I'm trying to relate this info in terms of practical considerations for all our friends here who are no doubt digesting every morsel here.
escogold is offline  
post #6 of 46 (permalink) Old 04-20-2011, 12:47 PM Thread Starter
Member
 
VTBikeman's Avatar
 
Join Date: Aug 2009
Location: Brattleboro, Vermont, USA
Year: 1989
Make: Honda
Model: GL1500
Posts: 212
Post imported post

What this means is that if you figure the load on your alternator in watts your calculations may be off and you may draw more current from your alternator than you think.

As you know GL1200 eat alternators. They are rated for 360 watts.
If you figure this at 12 volts that means you can draw 360w/1v2=30 amps max. If you figure it at 14 volts, what it really puts out, the max is 360w/14v=25.7 amps max. That's a grip heater or 2 worth of difference. Makes the poor boy conversion look real good. 55 amps!

As far as I know these are the causes of alternator stators failures:

1. Bad connectors on the cable from the alternator stator to the voltage regulator. If they are heating up or discoloring they need to be replaced or eliminated with soldered joints. There are 3 windings on the stator. If one connection fails out of the 3 the entire load shifts to 1 winding.

2. Overloads from too much load. Too many lights, boom boxes, grip and tushie heaters etc.

3. Oil acid buildup eating up the insulation on winding on the stator. In the GL1200 the alternator sits in the engine oil bath. Change the oil often.

89 GL1500 111+K (not my 111+k, yet!)
86 Honda Elite 250 -3k miles

Past fun:
85 Suzuki 450
86 Honda VT 500
84 Interstate
1980 Panasonic Bicycle with 50 cc motor

Nothing in all the world is more dangerous than sincere ignorance and conscientious stupidity. - MLK, Jr. 1963
VTBikeman is offline  
post #7 of 46 (permalink) Old 04-20-2011, 12:54 PM
Senior Member
 
Join Date: May 2009
Location: Escondido, California, USA
Posts: 909
Post imported post

That's the ticket. BTW, great distillation of tech info. Thanks!
escogold is offline  
post #8 of 46 (permalink) Old 04-20-2011, 01:06 PM
Senior Member
 
ceasefire49's Avatar
 
Join Date: Oct 2009
Location: Florence, Arizona, USA
Year: 1984
Make: Goldwing Interstate 1200
Model: 1984 1200 I with many add ons
Posts: 1,093
Post imported post

Okay great..So I figured right with my limited Electrical skills. Now after reading your explanations I can attempt to impart this knowledge to people that are on the same playing field mentally with myself. I will baffle them with my new found knowledge and Brilliance. God I love this forum. That was a great post and explanation. Really after reading deals like this from those that posses and infinitely greater amount of knowledge then guys like me I wonder why you guys aren't working for Clymers,Chiltons or Haynes submitting updates and corrections to some of their mind boggling and unintelligible directions.

Never argue with an idiot. They will only bring you down to their level and beat you with experience every time.
ceasefire49 is offline  
post #9 of 46 (permalink) Old 04-20-2011, 02:32 PM Thread Starter
Member
 
VTBikeman's Avatar
 
Join Date: Aug 2009
Location: Brattleboro, Vermont, USA
Year: 1989
Make: Honda
Model: GL1500
Posts: 212
Post imported post

I'm available. Make me an offer I can't refuse!

Flattery is soft soap and soft soap is 90% lye.
But thanks.

89 GL1500 111+K (not my 111+k, yet!)
86 Honda Elite 250 -3k miles

Past fun:
85 Suzuki 450
86 Honda VT 500
84 Interstate
1980 Panasonic Bicycle with 50 cc motor

Nothing in all the world is more dangerous than sincere ignorance and conscientious stupidity. - MLK, Jr. 1963
VTBikeman is offline  
post #10 of 46 (permalink) Old 04-20-2011, 03:43 PM
Senior Member
 
MichiganWing's Avatar
 
Join Date: Mar 2010
Location: Muskegon, Michigan, USA
Model: 2007 Gl1800 HPN
Posts: 1,672
Post imported post

Yeah...what HE said !

Shiny Side Up !
Jim
MichiganWing is offline  
Closed Thread

  Steve Saunders Goldwing Forums > Forums > Goldwing Technical Forum

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Steve Saunders Goldwing Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
3-5 volts delivered to the coils? tmyrm Goldwing Technical Forum 5 07-21-2010 09:07 AM
70 volts AC but grounded out JBz Goldwing Technical Forum 3 07-05-2009 05:40 AM
How many volts are ok on stator test? charlied Goldwing Technical Forum 2 04-12-2009 10:38 AM
7 Volts regulator The New Owner Goldwing Technical Forum 16 07-25-2008 09:45 AM
bouncing Volts rougemed2 Goldwing Technical Forum 9 05-16-2007 04:56 PM

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome