Join Date: Apr 2002
Location: Dandridge (Near Knoxville), TN, USA
Re: Another Stupid Battery Question
When the alternator light on the instrument panel just goes out the alternator voltage is the same as the battery voltage, so it is just keeping up with the current draw for the bike. Any RPM above that is charging the battery, slightly just after the light goes out to higher as the RPM increases.
The alternator light is a very important part of the alternator circuit. The current flow through the light before the engine starts running is used to "boot" the alternator. Without that small current through the rotor winding there may or may not be enough residual magnetism in the rotor to start the voltage producing process.
Some of us have had charging problems related to the wire from the indicator to the rear of the alternator getting loose or coming off, causing a no charge condition which you will not be aware of until it is too late since there will be no indicator light.
Always glance at that light when you turn on the ignition to be sure it is on before starting the ignition, and that it then goes out after start. If it never comes on, you have a problem.
I don't want to achieve immortality through my work...I want to achieve it through not dying.
EX: '01 Black LT, BAT BYKE (Totaled at 110,000 miles)
IBA SS, BB, BBG, 10/10ths.
No bike now, but maybe in the future.