Here is the super fast way to tell if a golf cart is a 36 Volt or 48 volt battery system. You can just peek at the charging plug hole and immediately see what voltage it uses.
With an EZGO golf cart a 36 volt will have a rectangular shaped plug.
An EZGO 48 volt golf cart will have a triangle shaped plug.
With a Club Car a 36 volt cart will rectangular shaped plug.
A Club Car 48 volt cart will have a round plug.