*2.2.3 Disadvantages*

The power transfer in short transmission distance is commonly achievable with good coupling coefficient which depends on the medium between coils whether it is air or any material with permeability 1 or above. In addition, the best coupling coefficient is obtained when the coils have the same dimensions, negligible gap and they are perfectly aligned. The alignment of the transmitter not correct with the receiver has been the first challenge to overcome in this technology. Therefore, the charging appliance are usually fabricated in a similar size in order to have a visible matching. Although the system efficiency and power transferred can be maximised, the following problems can arise in these systems.
