I've pursued the idea of having the battery charger top out at <= 55 volts, which would indeed be a great solution, but after much searching I'll be darned if there's a lithium ion battery charger out there which is small-ish, of reasonable cost, and has a suitable adjustable voltage range and adjustable amperage (or is limited to <= 15 amps).?
Victron makes what would be the perfect charger but it sadly isn't available in a 48 volt version.
So, just thought I'd ask if anyone might have knowledge of, or an idea where to look for, such a charger. :)