So I noticed the other day when I went to start my bike that the battery was dead. And tonight when I had it running in the garage, I noticed that at idle the head light was much dimmer than it was when the motor was reving. This is making me think that the alternator is bad on my bike. I'm just not sure how the charging system on a bike works. I know how a car charges its battery, but i'm not 100% sure how a bike does it. I think I need to address this problem though. Any help would be greatly appreciated. Thanks!

 

It could be the battery. Mine was doing that as well but the battery was stuffed, I have replaced it with a much better one and it's fine now. It might pay to test the R/R unit and battery first before you touch the alternator.

 

With a standard regulator the bike won't charge much below 3000 revs.
Put a voltmeter across the battery at 3000+ revs and if you get 14-15.5 volts, your battery is tired.
If you get 11-12 Volts, the regulator is likely not working.

 

What is the R/R unit?

 

Regulator/rectifier, it does all kinds of freaky electrical ****.

Damn I hate electrics, when the smoke gets out it's farked; extent of my electrical knowledge.

 

My understanding is: It regulates the amount of power given to the battery by dumping the excess power made by the alternator so that it only gives a steady charge. and keeps the battery toped up.

 

Yes, that is true for the regulator part of the circuitry.
The rectifier part changes the AC output of the alt. to DC as the battery is storing DC charge.

A rectifier is an electrical circuit.
A habanero pepper is referred to as a rectum frier. Don't get the two confused.

 

Your battery is finito most likely

Check the R/R plug at the regulator under the left side of the rear tail fairing
if it shows any signs of scorching / burning the R/R is done, then check the next
plug midways along that harness to the stator for the same and clean any corrosion

How old is the battery ? Motobatt MBTX14AU is a great replacement battery BTW

 

I think the battery is 3-4 years old. It was the cheapest battery I could buy at Walmart at the time. I was just a poor college kid and couldn't afford a real battery.

 

hey we all have budget limitations at times , hey 3 to 4 out of a Walmart Battery
must be a record they are usually only good for 2 or maybe 2 1/2

Grab the motobatt man if ya can on Ebay ...... make sure your R/R is good first


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