[dtbaker]

I have a fairly rare, ultra-lightweight English 2-seater, a '59 Berkeley,...bursts in the high 60mph (like the orig. 20 hp ICE), ...maybe 10 miles on the freeway, and a total usable range near 50 mi.

sounds like 120v worth of 160ah would be a fab build..... w.a.g. You MIGHT even get by with 100ah, but the 50 miles would lean to the higher capacity as a better bet. sticking to 120v would lower max amp pull while holding to the lower v rated (less expensive) components.

d