Alternators vs Generators

 An opinion I provided for a Comanche owner asking for some perspective on replacing his generator with an alternator:

There are plenty of items to consider when it comes to alternators vs generators:

•  - an alternator is lighter
•  - an alternator makes lots of power at low idle
•  - an alternator could be considered less reliable and has a bit more of a chance to fry things when it goes wrong
•  - generators are heavier
•  - generators do not charge the system at low rpm
•  - generators could be considered more reliable and less prone to fry things if they go wrong
•  - generators can make power if the battery is totally dead.  

Realistically, that last issue is only relevant if you do something like hand prop the engine and are hoping to charge the battery.  Or if perhaps you had a total melt-down of the battery in flight that actually disconnected it or something like that.  (As a side note I have actually been in the cockpit running the throttles while a mechanic hand started a Comanche 250 with a three bladed prop and a completely dead battery.  It was a tense and careful business but the battery charged - something not likely with an alternator.)

I have chosen to keep my Comanche with her generator.  I have replaced the regulator with a solid state one, the landing lights with LEDs to reduce power, it has a modern and light starter, and copper welding cables for main power wiring.  I am still careful not to have too many electrical things going when sitting on the ground waiting for a clearance.

This is a good article.  Note the references at the bottom for vendors:  ttps://www.aopa.org/training-and-safety/students/solo/special/alternators-and-generators