I have had the Halogen bulbs from Classic and Vintage bulbs for more than 8 years, before that I had the 50 cp bulbs, with the 50 cp bulbs I had to crank up my charging rate to have them bright, then I put in the Halogen bulbs--in the original sockets, with the original wiring, it was a miracle, now I could see at night, and I could cut the charging rate back, also now there is a barely perceptable change in light output when the generator goes off charge at idle.
The focus was the same as with regular bulbs, and there is a definite difference between high and low beam.
I can still have a slight + charge with the original generator and have the lights on, the light system with the halogens takes 10-11 amps with dual tail lights.
I think there are "cheaper" copys of these bulbs being sold that do not work as well, but I know the Classic and vintage bulbs work. --i bought mine at Hershey and in 8 years of use (about 50% of my driving is with the lights on)I have yet to need the spare bulb I bought.
In my testing I have found that they will light up reflectors on the poles and signs for more than 2/3 mile --at least 8 poles ahead.
You do NOT need to have an alternator to have Halogen bulbs.