Thanks for the info, I am just prepping for the future, I would like to use the Mobile Charger for awhile and see how that works out, but want the flexibility of adding on WC without having to getting another feed from the main breaker. The sub panel solution sounds good. Would there be a problem if I install100 amp and just use the Mobile Charger for the time being?
Yes, because you may not install a 50A receptacle on a 100A breaker. However, you *can* run a 100A-rated conductor (#2 or #3 in conduit - #2 NM/Romex doesn't count) with a 50A breaker and a NEMA 14-50, then swap out the breaker in the future should you change it.