Seriously though, Kathy, thank you for clarifying the difference between EarthX and Shorai and similar batteries. That gives additional food for thought at least.
Also, I think it is clear that EarthX provides no overvoltage protection above 60v or thereabout and a crowbar OVP is needed.
Regarding the PM alternators and the 20 amps, in fact I am thinking about putting a PM alternator on the other end to be belt driven, so I share Charlie's concern and, unfortunately, I am still confused where this 20 amp threshold is coming from. But it's irrelevant as if a battery has no OVP protection above 60v it may as well have none. So, crowbar OVP is required in any case and it will deal with any overvoltage situation whether it is under or over 60 volts and regardless of whether it is a traditional or a PM alternator.
I just got burned with the NavWorx fiasco, and i am accutely aware that the experimental market is strictly builder/owner beware, and that the vendor assurances are not worth much as the buck stops with me. Which, btw, is Just the way I like it. But at the same time, please forgive my scepticism and please understand my efforts to educate myself as it is my life that's on the line.
Building a Panther, but lurking here, like many others