No, you do not necessarily need 3 phase power to charge electric cars. Electric vehicles can be charged from both single-phase and three-phase power sources.
In many cases, home charging stations for electric cars are designed to be plugged into a standard household outlet, which provides single-phase power. This is sufficient for many electric car models and will allow you to charge your car overnight.
However, for faster charging, three-phase power can be used. This is often the case for public charging stations or in commercial and industrial settings. Three-phase power provides more power than single-phase power, allowing for faster charging times.
In summary, while three-phase power can provide faster charging times, it is not necessary to charge electric cars, and many electric car owners simply charge their vehicles using a standard single-phase power outlet.