Multi-lithium-battery electrical core voltage difference balancing system

Abstract

The invention discloses a multi-lithium-battery electrical core voltage difference balancing system, which comprises an external control MCU, a plurality of groups of electrical cores connected in series, and capacitors on each group of the electrical core, wherein the positive electrodes of the N group of the electrical cores are connected to a first MOS pipe drain electrode, a first MOS pipe source electrode is connected to the negative electrodes of the N group of the electrical cores through a first energy transfer device, the positive electrodes of the N+1 group of the electrical cores are connected to a second MOS pipe source electrode through the first energy transfer device, a second MOS pipe drain electrode is connected to the negative electrodes of the N+1 group of the electrical cores, the positive electrodes of the N+2 group of the electrical cores are connected to a third MOS pipe drain electrode, and a third pipe source electrode is connected to the negative electrodes of the N+2 group of the electrical cores through a second energy transfer device. According to the present invention, with the multi-lithium-battery electrical core voltage difference balancing system, the battery pack monomer series connection circuit charging voltage difference is less than 10 mv, the discharge capacity is 5-8% higher than that before the battery is improved, the charging temperature raising of the battery pack protection plate is reduced by 5-10 DEG C compared with the charging temperature raising in the prior art, and the a battery thermal safety is significantly improved.

Description

technical field [0001] The invention relates to a battery assembly, in particular to a multi-cell lithium battery cell pressure difference balancing system, which belongs to the technical field of lithium batteries. Background technique [0002] Cylindrical lithium-ion batteries are divided into lithium cobalt oxide, lithium manganese oxide, and ternary materials; batteries with three material systems have different advantages, and batteries are widely used in notebook computers, digital cameras, lighting fixtures, toys, power tools, and portable mobile phones. Energy and other fields; because of the voltage and capacity requirements of the lithium battery module in the prior art, many internal structures of the module use the series-parallel connection of cells to achieve the performance requirements of the module; when the cells are connected in series and parallel, due to the cell manufacturing process The process leads to differences in consistency. When the battery pack...

AI Technical Summary

Problems solved by technology

[0002] Cylindrical lithium-ion batteries are divided into lithium cobalt oxide, lithium manganese oxide, and ternary materials; batteries with three material systems have different advantages, and batteries are widely used in notebook computers, digital cameras, lighting fixtures, toys, power tools, and portable mobile phones. Energy and other fields; because of the voltage and capacity requirements of the lithium battery module in the prior art, many internal structures of the module use the series-parallel connection of cells to achieve the performance requirements of the module; when the cells are connected in series and parallel, due to the cell manufacturing process The process leads to differences in consistency. When the battery pack is charged and discharged, there will be problems of cell voltage difference and capacity difference, which will seriously affect the performance of the battery pack. The performance of the charging cells is inconsistent, and the energy consumption method is used to achieve the charging consistency of the cells. The general balancing circuit, such as the attached figure 1 As shown in , when the voltage of battery cell BT1 is high, the external control will turn on the MOS, and the battery will discharge the battery cell through the circuit of current I, and the balanced current size is determined by the resistance R2 of the series circuit; when the battery cell BT1 is discharged, this The energy of the battery is consumed by components such as resistor R2 and MOS in the loop; the disadvantage of this technology is that the energy of the battery cell is consumed by the loop and is not effectively used, resulting in waste; in addition, a large amount of heat is generated by energy consumption, which makes the local temperature of the battery pack rise, which may pose a safety risk

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