Do alternators last longer at higher rpm or at idle? Some of my friends say at higher rpm. And no rude ignorant answers thank you
G-day, Personally i think they would last longer at the lowest rpms, cause it puts less strain on the bearings and the copper windings and brushes. The main component that gives out on alternators are the needle bearings. Alternators have lots of moving parts that wear out cause of dirt and temperature stress. Also good to keep any water out of them too, If you ever have to clean your engine bay.
Yes the higher the rpm the sooner the bearings will wear out. Contaminates like oil grease are the worst, then water try to keep them clean. The amount of heat created depends on the load, the more power you use, the more the alt has to make (up to it's maximum current output), the higher the current the hotter it gets.