I have direct fit halogen bulbs, have stock generator , never use charger or maintainer, about 40% night drives, got 16 years out of last optima, 4 more years out of 10 year old and 12V cut in 1/2 , I do run a higher than most charge rate (14amps), on long day trips I turn on headlights for a while (seat of pants time method), could drive all night with 4 hours of day driving
The charge rate needs to be adjusted to cars use, most set it too low for their use
At one time I would set at 18 amps for 50 cp regular bulbs to make them bright, the generator has survived this use untouched for45 years, I do leave the cover band off for ventilation