Theoretical researches of efficiency of electric energy transfer in the wireless charger of inductive type with serial resonance in circles of transmitting and receiving coils are carried out. It is shown that this efficiency depends on the parameter (the product of the magnetic coupling coefficient and the Q- factor of the coils) and the ratio of the active resistances of the battery and the coil. It is shown that there is an optimal value of this ratio, at which the efficiency of the device is maximum (when ) and its value increases monotonically with increasing parameter . Moreover, to achieve an efficiency greater than 0.8, it is necessary to have a system of coils with a value of 10. The graphical dependences that determine the value of this efficiency as a function of these two parameters and set the allowable interval for changing the resistance ratio in terms of high energy efficiency. Numerical calculation of the high-frequency magnetic field (with an operating frequency of 100 kHz) generated by the coils was performed, in two cases - in the absence of shielding and in the presence of aluminum electromagnetic screens and showed high efficiency of such screens. The peculiarity of the calculation is that to determine the values of complex currents in both coils, which depend on the mode of operation of the whole device, use their preliminary calculation based on the created Simulink-model of the device. References 14, figures 5, table 2.

Aspects of the practical implementation of Vehicle-to-grid (V2G) technology for bi-directional energy exchange when connecting electric vehicles to a public electric network based on the use of the designed powerful bi-directional charging converter are considered. It is intended to the transmission of electric power from the distribution network to traction batteries of electric vehicles or hybrids for their charging and vice versa-from batteries to public electric network in order to smooth out the daily load schedule. The main technical solutions and features of the practical implementation of designed semiconductor converter that can use as part of powerful charging stations of electric vehicles and hybrids are presented. References 9, figures 3, table 1.

The work gives a detailed description of lithium-ion batteries and methods of their use in technical devices of various purposes. The basic technical characteristics of the main types of industrial lithium batteries are presented and it is shown that lithium-iron-phosphate, lithium-titanate and lithium-carbon-titanate batteries are currently used in autonomous electric vehicles. The work also analyzed the results of bench tests of lithium-titanate and lithium-carbon-titanate batteries in terms of their temperature state at different values of external temperature and different levels of charge-discharge currents. The results of the tests showed the limit values of the battery heating temperature, as well as a change in the charging process at sub-zero ambient temperatures, which requires the necessary measures - cooling or heating - when assembling the traction battery from the tested elements. Bibl. 8, figure, table 12.