Let's do a reality check...
What exactly is ypur alternator?
Make of vehicle? Model? If a Ford peer through the holes or slots in the housing. What color insulation on the stator wires? Green? Purple?
About 90% of the motorhomes I check couldn't deliver more then 40 amps to a batteey bank if an H-bomb was tied to the other end. 4-3 cell batteries connected to a 120 amp alt. can use a NUMBER FOUR AMERICAN WIRE GAUGE cable connected to an 80 ampere breaker then through a charge divider like a Sure Power. This cable connects directly to the alternator output stud and nowhere else. It is stacked atop the original cable terminal. Because of the length output would be ultimately limited to around 80 amperes. Do you have enough battery to accept 80 amp charge rate?
And for those who scream about excessive heat. Save your breath. Instead direct your energy at mounting 4' diameter bull horns on your roof so you can drive around Phoenix on a 108F summer eve screaming "you Can't Do That!" Into a microphone.