Cable is 6mm² minimum, may need 10mm² if the cable run is long (saves a bit of wasted power).
That’s a new one on me! I imagine you are refering to whats known as voltage drop, however there is no wasted power either way?
It is important to take into account the specification of the charger and whether it has an RDC-DD when choosing the type of RCD. Whilst type A RCD’s maybe the most commonly used, as it will work upto 6mA DC. You need to take into account, that over 6mA however a Type A device could be blinded and fail to operate correctly. If the charger does not have RDC-DD a type B RCD would be used and so on, for example, an AC RCD would not be fitted upstream of a Type A, F or B, as the load characteristics could impairoperation of the Type AC when in series.
Regulations also require a surge protection device to be installed, when installing a charger. This is because an SPD is not fitted within the charger 🙂