The Battery light on my 2.2L Chevy engine will occasionally illuminate. It stays illuminated for anywhere from a few seconds to several minutes. The weird part is that when it is illuminated, any electrical equipment operates a little faster/brighter (environmental fan speeds up, lights brighten up slightly). Usually, changing the load (turning on/off air conditioner, for example) will remedy the light, but not always. The condition does not seem to correlate to any given engine speed or electrical load, and it does not sound like the belt is slipping. Ideas?
The charging system should be tested to determine if the voltage regulator is functioning correctly. This is what controls the voltage from alternator to the battery to the vehicles electrical system. If for some reason the voltage regulator detects that battery is low on charge when it isn’t, it will allow too much voltage from the alternator into the battery, causing the symtoms you describe.