The invention enables efficient wireless power transfer, and charging of devices and batteries, in a manner that allows freedom of placement of devices or batteries in one or multiple dimensions. Provided is a base unit for wireless power transfer or charging through a time varying magnetic field. The unit typically includes a magnetic material or layer that guides magnetic flux generated by a charger coil as to create a preferential path for returning magnetic flux from a receiver coil in one or multiple dimensions. The receiver may include a magnetic core having a magnetic permeability exceeding 1 with copper Litz wire around a ferrite core. With power receivers proximate to the base unit, the base unit coil may inductively generate a current in receiver coils or receivers associated with the power receivers. Uni-directionally or bi-directionally wireless communication protocols include NFC, Bluetooth, WiFi, and etc. control and optimize power transfer therebetween.