The engine driven generators available for the Warner and Kinner engines are not very good at generating and weigh a ton. A much better alternative is the wind driven Turbo Alternator model BPE-14 from Basic Aircraft Products. I mounted it on the belly of the fuselage, right between the main gear. It puts out about 6 amps at 85mph. It keeps my battery fully charged. It puckers up a bit when I’m running the radio and then turn on all the lights and strobe, but that is a rare occurrence. It is extremely quiet. I can tell by the voltage meter it’s working, but there is no noise or vibration. After nearly 550 hours with it, I’ve never been caught out on a trip with a dead battery. Plus, it saved a ton of weight!