Battery pack

Abstract

The invention discloses a battery pack. The battery pack comprises a cathode terminal and an anode terminal as well as a plurality of cell groups, a plurality of switches in series and a microprocessor. Each of the cell groups is connected to the cathode terminal and the anode terminal, and comprises a cell, an electrical characteristic detection module, an anode switch and a cathode switch, wherein the anode switch is connected in series between the cell and the anode terminal, and the cathode switch is connected in series between the cell and the cathode terminal. And the plurality of cells are connected in series via the plurality of switches in series. The microprocessor controls the closing and turning-off of the plurality of switches in series and the anode switches and the cathode switches of the plurality of cell groups. The plurality of cells are connected in series automatically when the battery pack is to discharge; and the cells are connected in parallel automatically when the battery pack is to be charged. During charging, the electrical characteristic detection module of each cell group can detect electrical characteristics of the cell, and the microprocessor controls the cell to be charged or not according to the electrical characteristics provided by the electrical characteristic detection module, so that it is ensured that each cell is not overcharged and is prevented from being damaged by overcharge.

Description

technical field [0001] The present invention relates to a battery module, in particular to a battery module, which can control the charging and discharging of internal battery cells, so as to avoid damage to a single battery cell due to overcharging and over-discharging. Background technique [0002] Battery modules are usually used in electronic devices such as electric vehicles, notebook computers or mobile phones to provide power required by various electronic devices. [0003] The above-mentioned various electronic devices are usually equipped with a battery management system (Battery Management System, BMS), which is used to detect the power of the battery module and switch the charge and discharge of the battery module to avoid overcharging or overdischarging of the battery module. Please refer to Figure 9 The aforementioned battery management system mainly uses a voltmeter 91 and an ammeter 92 to measure the voltage difference, charging current and discharging current...

AI Technical Summary

Problems solved by technology

[0004] Although the above-mentioned battery management system can control the charge and discharge of the battery module, due to the internal structure of the battery module, the control effect of the battery management system on the charge and discharge of the battery module is quite limited, mainly because the battery module (Pack) usually must contain multiple Battery cells (Cell) connected in series, and each battery cell will have different polarization characteristics due to different processes, materials and temperatures, so the internal resistance of the battery cells is inconsistent, and the charging and discharging characteristics are inconsistent; For example, if a 4.2V battery unit is used, the battery module must contain more than a dozen battery units connected in series. In addition, the charging and discharging characteristics of each battery unit are different. When the battery module is charged, all battery units will be simultaneously Charging, so that the charging speed of the battery cells with lower internal resistance is faster than that of the battery cells with high internal resistance, so some battery cells are fully charged but some battery cells are still charging. At this time, the battery module is still charging until all The battery cells are all fully charged, and the fully charged battery cells are in an overcharged state and are easily damaged. In severe cases, the battery may even overheat and explode.

[0005] In order to reduce the above problems, when assembling the battery module, the battery module assembly factory must first go through a step of multi-channel measurement, and assemble the battery cells with similar polarization characteristics into a battery module. However, this step can only be Minimize the consistency difference of each battery cell in the battery module, and since the polarization characteristics of the battery cells may still change after they are assembled into a battery module, the effect of the above quality control steps on reducing the uniform internal resistance of the battery cells is still bad

[0006] To sum up, since the existing battery modules are charged and discharged with multiple battery units with different polarization characteristics, in addition to making the battery management system unable to effectively manage the charging and discharging of the battery modules, some easy-to-charge and easy-discharge battery units It is also easy to be damaged, and the multi-channel measurement process still cannot improve the defects caused by the poor consistency of the battery cells. Therefore, it is necessary to improve the structure of the battery module to solve the defects caused by the different polarization characteristics of the above-mentioned battery cells.

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