1. Using a 3-pin charger frequently can be dangerous
A 3-pin domestic socket is not designed for continuous high-power usage, so most manufacturers recommend three-pin charging only in emergencies. A 3-pin plug charger is a high-drain device, meaning that you will need to run your 3-pin socket at 2.3kW or even 2.5kW for long periods of time. Running a domestic socket this close to its maximum 3kW capacity puts a strain on your circuit, the cables, and the socket, with the potential to cause serious problems, such as overheating and, in worst-case scenarios, fires. This is not the case for dedicated home chargers, as they are designed to support the electric load needed to charge an EV without any cause for concern.
When I ran my i3, my pal had a PHEV 3 Series, he just charged it overnight from a std 13 amp garage plug, never had any issues in 3 years of varied use, most decent spec EV's will have an option in the charging menu to tweak back the charging rate (so pick say 10 amps instead of 13)
When my posh hi speed charger was faulty I had to use the supplied 3 pin cable for several weeks and again had no problems
