Research On The Monitor And Control Module For Battery Running State

Lithium-ion battery is a new generation of rechargeable battery following lead-acid battery and nickel-hydrogen battery. It is widely used in portable devices such as mobile computers, digital productions and communication apparatus, owing to its small size, large capacity and little environmental pollution. Electric Vehicles (EV) gives much attention to the battery, and it is predicted to become the main power for Electric Vehicles (EV). The monitor and control of the running state is an important part for the battery, because it can manage the battery efficiently, improve its service efficiency and service life, it can protect and gives the warring when the battery is in the dangerous. Therefore, the research on the monitor and control module for battery state is very important.In the present study, the design of the monitor and control module for the battery-running state is introduced, including the theoretical analysis, designing and completing the monitor and control module. The external behaviors of the Lithium-ion battery are studied and analyzed through lots of experiments, including the charge and discharge characteristics, impedance characteristics, and the capacity characteristics and so on. This thesis gives emphasis on the working characteristics of the Lithium ion battery under charge and discharge modes, research on the methods of calculation for the state of charge (SOC) and the factors that can affect the SOC. This thesis concerns to gather the voltage, current and temperature characteristics and the method of calculation for the state of charge. The module can communicate with the smart charger and the host by the bus. The module will itself react if a dangerous situation should occur, which including under-voltage, over-voltage, over-current and short-circuit. It can block the operation of the battery and stop work, even completely shut down the working circuit to protect the battery. In the module we design the liquid crystal display to show the characters and the running state of the battery.The module, making the new generation of microcontroller (PIC18F458) as the core of the whole system and with peripheral circuits such as the circuits to gather...