Conversion device for mutually converting serial connection and parallel connection among monomers or modules in battery pack

Abstract

The invention discloses a conversion device for mutually converting serial connection and parallel connection among monomers or modules in a battery pack. The conversion device comprises a fixed part and a rotating part, wherein the fixed part and the rotating part are disk-shaped, connecting sheets are arranged on the fixed part and are uniformly arranged around the center of the fixed part, the rotating part and the fixed part are coaxially connected, parallel connection contacts and serial connection contacts are arranged on the rotating part and are uniformly arranged around the center of the rotating part, the surface of the fixed part, which is provided with the connecting sheets, is opposite to the surface of the rotating part, which is provided with the parallel connection contacts and the serial connection contacts, when monomers or modules in the battery pack are connected in parallel, the parallel connection contacts are in contact with the connecting sheets, and the serial connection contacts are separated from the connecting sheets; and when the monomers or modules in the battery pack are serially connected, the serial connection contacts are in contact with the connecting sheets and the parallel connection contacts are separated from the connecting sheets. The conversion device for mutually converting serial connection and parallel connection among the monomers or modules in the battery pack is simple in structure, and is capable of rapidly and conveniently realizing conversion of serial connection and parallel connection among the monomers or modules in the battery pack.

Description

technical field [0001] The invention relates to a conversion device for mutual conversion between series connection and parallel connection among monomers or modules in a battery pack. Background technique [0002] With the country's increasing emphasis on environmental protection and the gradual enhancement of people's environmental awareness, most bicycles have been replaced by electric bicycles, and new energy vehicles are also gradually replacing fuel vehicles. Both electric bicycles and electric vehicles are inseparable from a core component---the power supply system, and this power supply system is not like a mobile phone, which only uses one battery, but is composed of many batteries connected in series and parallel. Lithium-ion batteries are currently the focus of attention in power systems. However, there are still some problems when lithium-ion batteries are used in series. Taking lithium iron phosphate battery, a category of lithium ion battery, as an example, ...

AI Technical Summary

Problems solved by technology

But when used in groups, if a certain battery self-discharges too much, it will be discharged first when it is discharged after a period of time, and the capacity of other batteries has not been fully discharged at this time. When charging, it will be affected by the charging capacity of other batteries. Limiting the battery with large self-discharge must not be fully charged, so as time goes by, the capacity that the battery with large self-discharge can be charged is less and less compared with other batteries, and finally the capacity of the entire battery pack is unqualified; 3. Battery Polarization difference between cells in the battery pack: Even if the initial performance of the batteries in the battery pack is relatively similar, the polarization state of each battery in the battery pack will inevitably be different after long-term use. When charging in series with constant current, no matter The size of the battery polarization, the charging current through each battery is equal, which will accelerate the decay of battery life with large polarization

In order to solve the above problems, in addition to selecting batteries with better consistency for pairing to minimize the initial difference between the battery cells, the common method to solve the self-discharge difference and capacity difference is to use equalization + charging protection Although this method can effectively solve this problem in principle, it has the disadvantages of high cost and unproven reliability in implementation, and it cannot solve the problem of polarization differences between monomers.

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