Steve Saunders Goldwing Forums banner
Status
Not open for further replies.
1 - 12 of 12 Posts

·
Premium Member
Joined
·
57 Posts
Discussion Starter · #1 ·
imported post

I have a good battery and a new alternater, at and above 1000 rpm i have 13 to 14v. at idle about 850 to 900 rpm i have 12.5v. The dealer says thats normal for the 1500, seems funny to me! I have seen alot of 1800 with alot of extra lights idle at 14v. Should i idle at 13+, Thanks for feedback.
 

·
It aint rocket science
Joined
·
3,968 Posts
imported post

My stock 88 will idle all day long at 14.0V with no fans on. Above 2k RPM should be charging at 13.6-14.2V. If less than 13.6V you got problems.

JD
 

·
Member
Joined
·
267 Posts
imported post

rickals wrote:
I have a good battery and a new alternater, at and above 1000 rpm i have 13 to 14v. at idle about 850 to 900 rpm i have 12.5v. The dealer says thats normal for the 1500, seems funny to me!
That's exactly the same results my stock alternator did. Perfectly normal. I now have a Compufire alternator fitted and if you drop the idle down to 750 rpm or less then that will also cease charging. Crank it up to 850 rpm or more and it's charging good again. Every alternator has a charging/rpm cut off point, three guesses what our alternators are? ;)

Regards, Tony.
 

·
It aint rocket science
Joined
·
3,968 Posts
imported post

Waldorf wrote
That's exactly the same results my stock alternator did. Perfectly normal. I now have a Compufire alternator fitted and if you drop the idle down to 750 rpm or less then that will also cease charging. Crank it up to 850 rpm or more and it's charging good again. Every alternator has a charging/rpm cut off point, three guesses what our alternators are? ;)

Regards, Tony.
Curious if you have owned the bike since new and it was showing this behavior. At what mileage was it replaced? Did not the dealer replace it under warranty.

JD
 

·
It aint rocket science
Joined
·
3,968 Posts
imported post

Well , if you do not want to discuss it I will have to make a couple of assumptions. And that would be you got one of the failed Chinese alternators and it was out of warranty or was bought used with a bad alternator.

Either way Honda did not design an alternator to not charge at idle with their 40A alternators which is more than powerful enough to keep the battery charged if working correctly. It is not normal, sub standard parts are to blame.:smiler:

JD
 

·
Member
Joined
·
267 Posts
imported post

DriverRider wrote:
Waldorf wrote
That's exactly the same results my stock alternator did. Perfectly normal. I now have a Compufire alternator fitted and if you drop the idle down to 750 rpm or less then that will also cease charging. Crank it up to 850 rpm or more and it's charging good again. Every alternator has a charging/rpm cut off point, three guesses what our alternators are? ;)

Regards, Tony.
Curious if you have owned the bike since new and it was showing this behavior. At what mileage was it replaced? Did not the dealer replace it under warranty.

JD

No dealer was involved in any way. No dealerships or any other mechanics work on my vehicles. I do all my own work from the smallest of tasks to full structural work & painting toanything else in between. My day job is electronics & mechanical engineering. I simply replaced the alternator for the Compufireas Irequiredthe greater available output it could provide. The OEM alternator was working just fine when I removed it. I still have it boxed up just incase I need it again. Your alternator may simply have a cut in output speed just below your current idle speed in which case you are very lucky indeed. It's all to do with the voltage regulator charecteristics and ambient & opertaing temperatures that the alternator operates in. In my case, when the temperature is quite low, just below 800 rpm thealternator cuts in. When in Europe in the heat, the alternator cut in just above 850 rpm. The output of the Compufire is alsotemperature compensated so the hotter the alternator the lower the available output, the lower the temperature the higher the output "depending on the load required". Another variable is the rpm indicator gauge. These differences are onlyplus or minus 100 rpm, so is the voltage regulator perfect? is the bikes rev counter 100% accurate? are the ambient temperatures the same? These are all small variables in the grand scheme of things.

You are fortunate that your bike is charging at idle, on the other hand some of us are less fortunate. But overall we are having a great time and all is well with the World.

;)

Regards, Tony.

Regards, Tony.
 

·
Still Learning
Joined
·
13,274 Posts
imported post

Trickals wrote:
I have a good battery and a new alternater, at and above 1000 rpm i have 13 to 14v. at idle about 850 to 900 rpm i have 12.5v. The dealer says thats normal for the 1500, seems funny to me! I have seen alot of 1800 with alot of extra lights idle at 14v. Should i idle at 13+, Thanks for feedback.
What year is your 1500?
Has it been cleaned and brushes replaced? This might be all it requires.
What are you measuring the voltage with, digital or analog, on bike volt meter or with a multimeter?
 

·
Premium Member
Joined
·
28,832 Posts
imported post

My 1993 GL1500 would not charge the battery at Idle (850)it was the straight 12.4v. Rev it up above 1600 rpm it would charge just fine 14.3v. I was told that is the Honda Way and people have complained about it all the years of the 1500.With my new bike I have a Compufire Alternator and a gell battery. Thisbike has aAftermarket Volt meter and At idle or any rpm it will give me 14.4 volts if the battery is low or just after it starts. Then it will drop back to the 13.5v range. On my original 1500 Ieven changed the brushes in the Alternator and that changed nothing and others here again said it's the nature of the beast and if I didn't like it I should get a aftermarket alternator.Hence the Compufire in this bike...Pirate..
 

·
Premium Member
Joined
·
391 Posts
imported post

Don't get voltage and current confused, remember voltage is inversely proportional to current, meaning the higher the voltage the less current you have. If your voltmeter is reading 14+ volts, then the regulator on the alternator is seeing the battery as charged and reduses the current supplied to the battery, this prevents the battery from being over charged.
One should expect to see a voltage drop upon starting then the voltage will build to max volts as the battery is charged and current is redused. If your amperage demand exceeds the capabilities of the regulator you will see the voltage start to drop and continue to drop as amperage demand continues.
A faulty battery will cause a voltage drop due to high current demand by the battery not charging.
To many lights exceeding the rated amperage output of the regulator will cause a voltage drop.

If you getting an excessive voltage drop then you need to find out just what is causing it, by replacing the alternator to compensate for the drop is a huge waste of money. One should think about replacing the alternator if they are installing equipment that exceeds the rated output of their existing regulator.
 
1 - 12 of 12 Posts
Status
Not open for further replies.
Top