I do not understand the need for a second alternator. I do not understand the need for an alternator that produces over 100 amps. A good or bad gen set will do every task faster and better. The only good feature of a large alternator, or two units or a high output unit is the rate of a bank of batteries recharge. My Crown has just 2-900cca batteries. I also use several inverters. The refrig is 120vac and needs only a small inverter to work great.
After removing the air pump, connect some LPG or water or water/alcohol. Easy task for more power. Frank