If your living quarters were built within the last 30 years or so, you should not have any issues. If you are handy, replace the receptacle where you are plugging in with a heavy duty rated receptacle and use the screw terminals and not the back-stab type connections.
If older than 30 years, you want to make sure you do not have aluminum wiring (not used in every region but in some regions ) and if you do, make sure the connections are good at the receptacle and you will want to check the wiring frequently until you are certain there are no issues. If not aluminum, then make sure the circuit you are using is not overloaded in any way and is somewhat isolated from high current appliances (such as a heater, dehumidifier etc ). FYI, aluminum wire expands and contracts more than copper causing the aluminum wire to fatigue more and loosen or break at the connection point. If the residence is real old, be careful as there likely are too many receptacles on a circuit and the condition of the wire and the receptacles may not be as good as they should be.
When you flip to 12amps, for the first few charges, frequently take note of the temps at the receptacle and the plug. It should be warm but not hot. Hot is bad. Warm is ok. Cool is best.
FYI, on a 15 amp circuit, 12 amps is the maximum continuous load that should be on the circuit. That is why a dedicated circuit is recommended - it eliminates the chance that something else is plugged into the same circuit and drawing current just enough to heat up the wiring but not pop the breaker, especially if over a period of 14 hours.
Cheap receptacles and poor connections cause resistance and micro-arching which causes heat build up and eventually melts wires, especially if the circuit breaker or fuse is not the correct size or working properly. Cheap receptacles also cannot handle frequent plugging and unplugging and will wear down the contacts in the receptacle and will create resistance. Heavy duty receptacles last longer and resist wear better.
