Development of an Adaptive Lithium Battery Dynamic Charging System for Portable Devices

Traditional lithium-ion battery charging systems are characterized by a single charging mode, low charging speed, and low efficiency. They are thus difficult to satisfy the high requirements for battery life and safety of portable devices. For this reason, this research presents an adaptive dynamic lithiumion battery charging system for portable devices. This system adopts a new model combining a synchronous buck DC-DC circuit with a resistor divider circuit, significantly expanding the adjustment range of input and output voltages. Based on the constant current-constant voltage method of adaptive PID control and combined with the feedback control circuit of a high-speed digital-to-analog converter, precise control of output voltage and current is achieved, ensuring smooth transitions in charging modes and enhancing the safety and reliability of the system. Experimental verification indicates that this system has an input voltage range of 4.5V to 16V, an output voltage range of 2.704V to 7.644V, a charging voltage error of less than 0.71%, and a charging efficiency of over $\mathbf{8 0 \%}$. It can effectively meet the lithium-ion battery charging requirements of various portable devices and provides innovative and practical solutions for portable devices, national defense and military, aerospace, and other fields.