This new 120-Amp alternator option at 58 Volts for Mercedes Sprinter OEM bracket is something I had not seen before, and shows aftermarket vendors realizing the need to address the shift to 48-Volt (nominal) electrical systems.
The initial post almost 4 years ago was about Roadtrek introducing an innovative system that was ahead of its time, but was limited to 3,500 watts (which in fairness was plenty for AGM batteries). This new alternator is rated at over 6,000 watts, making it possible to charge a large lithium battery bank in a matter of a couple of hours.
Product release: Alternator for Mercedes-Benz Sprinter N62 Bracket - American Power Systems, Inc.®
P.S. — I think it’s wrong to think these types of motorhomes don’t have generators. Electricity is generated in a different manner using the vehicle’s engine, but in effect it’s still a generator. Again, not for everyone, but for some owners the entire system is better.