Stock charging sys @14.6, 15.4 , 16, 17 then 18 and poof

So my truck has been killing alts and volt regs for 2 months, 4 regulators and 3 alts. Ive looked over all of my charging sys and ive even went back to 1 bat, and pulled the alt to bat wire in my big 3 but i think its happening again, it starts out by going from a norm 14.6 up into the low 15s and stays there for a week or so even with headlights, heat, 2 4ch, and a 2ch at full tilt . From there it inches up to 18 and i get paranod bout my amps so i put there fuses and im left with no music. My truck is a 87 dodge d100 pickup wit a lil 318 v8 the only thing being powered by the bat is the lights, heater blower, and of course the ignition sys. Does anyone know wat da hell is happening wit my charging sys cuz im tired of replacing my bats, alts, n volt regs.