No small task. He definitely didn't slap this together. A lot of thought, design & building went into it.
But he only had to re-wind the alternator because of his high pack voltage.
For those of us with lower voltage vehicles, that step wouldn't be necessary. A normal alternator can be modded (through field control & RPM being the issues) to output up to 120v without re-winding.
Alternator Secrets