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CA-3146686-C - BATTERY PACK

CA3146686CCA 3146686 CCA3146686 CCA 3146686CCA-3146686-C

Abstract

A battery pack includes a cell assembly. The cell assembly includes a cell assembly positive terminal, a cell assembly negative terminal, a positive lead-out piece, a negative lead-out piece, a discharge path, and a protective element. The positive lead-out piece connects the cell assembly positive terminal to a battery pack positive terminal. The negative lead-out piece connects the cell assembly negative terminal to a battery pack negative terminal. The protective element is disposed on the discharge path. When the discharge current of the discharge path is greater than or equal to a preset current, the protective element turns off. The length of one of the positive lead-out piece or the negative lead-out piece close to the protective element is greater than the length of the other one of the positive lead-out piece or the negative lead-out piece away from the protective element.

Inventors

  • Guiwu Hu

Assignees

  • NANJING CHERVON INDUSTRY CO., LTD.

Dates

Publication Date
20260505
Application Date
20220125
Priority Date
20210126

Claims (13)

  1. 21 CLAIMS What is claimed is: 1. A battery pack, comprising: a housing; a battery pack inte 5 rface enabling the battery pack to be detachably connected to a power tool, wherein the battery pack interface comprises a battery pack positive terminal and a battery pack negative terminal; and a cell assembly located in the housing, wherein the cell assembly comprises a plurality of non-cylindrical cells a cell assembly positive terminal and a cell assembly negative terminal for 10 outputting electric energy from the cell assembly; a positive lead-out piece, wherein the positive lead-out piece connects the cell assembly positive terminal to the battery pack positive terminal; a negative lead-out piece, wherein the negative lead-out piece connects the cell assembly negative terminal to the battery pack negative terminal; 15 wherein a discharge path is formed by the cell assembly positive terminal, the positive leadout piece, the battery pack positive terminal, the cell assembly negative terminal, the negative leadout piece, and the battery pack negative terminal and configured to supply power to the power tool; and a protective element disposed on the discharge path, wherein the protective element is 20 configured to turn off the discharge path to disconnect the discharge path when a discharge current through the discharge path is greater than or equal to a preset current, and the protective element is a fuse independent of the positive lead-out piece and the negative lead-out piece, wherein: either, the protective element is connected between the positive lead-out piece and 25 the battery pack positive terminal; and a length of the positive lead-out piece close to the protective element is greater than a length of the negative lead-out piece away from the protective element; or, the protective element is connected between the negative lead-out piece and the 22 battery pack negative terminal; and a length of the negative lead-out piece close to the protective element is greater than a length of the positive lead-out piece away from the protective element.
  2. 2. The battery pack of claim 1, wherein the non-cylindrical cells are connected in series.
  3. 3. The 5 battery pack of claim 1, wherein the positive lead-out piece and the negative lead-out piece are made of metal.
  4. 4. The battery pack of claim 1, wherein the cell assembly comprises a first cell and a second cell, a positive electrode of the first cell is connected to a negative electrode of the second cell in series, the positive lead-out piece is connected to a positive electrode of the second cell, and the 10 negative lead-out piece is connected to a negative electrode of the first cell.
  5. 5. The battery pack of claim 1, wherein a discharge current of the battery pack is greater than or equal to 80 A.
  6. 6. The battery pack of claim 1, wherein a capacity of the battery pack is greater than or equal to 5 Ah. 15
  7. 7. The battery pack of claim 1, further comprising a cell elastic piece disposed around the cell assembly and configured to avoid a possible relative displacement between the cells due to a bump or a vibration.
  8. 8. The battery pack of claim 1, wherein each of the plurality of non-cylindrical cells is a flat bag-like structure. 20
  9. 9. The battery pack of claim 1, wherein the each of the plurality of non-cylindrical cells comprises a shell, and an aluminum-plastic film is used as the shell.
  10. 10. The battery pack of claim 9, wherein the battery pack is a pouch-type battery pack.
  11. 11. The battery pack of claim 1, wherein the width of the positive lead-out piece is in the range of 5 mm to 40 mm. 25
  12. 12. The battery pack of claim 1, wherein the positive lead-out piece is configured to have a first temperature when the battery pack is discharged, the negative lead-out piece is configured to have a second temperature when the battery pack is discharged, the protective element is disposed between the positive lead-out piece and the battery pack positive terminal, the first temperature is greater than the second temperature, and a length of the positive lead-out piece is greater than a 23 length of the negative lead-out piece.
  13. 13. The battery pack of claim 1, wherein the positive lead-out piece is configured to have a first temperature when the battery pack is discharged, the negative lead-out piece is configured to have a second temperature when the battery pack is discharged, the protective element is disposed between the negative lead-out piece and the 5 battery pack negative terminal, the second temperature is greater than the first temperature, a length of the negative lead-out piece is greater than a length of the positive lead-out piece.

Description

BATTERY PACK TECHNICAL FIELD [0001] The present disclosure relates to a battery pack and, in particular, to a battery pack arranged on a power tool. 5 BACKGROUND [0002] Based on the use requirement for portability, more and more power tools currently use battery packs as power sources. [0003] The existing battery packs for supplying power to power tools mostly use cylindrical lithium batteries. Multiple cylindrical lithium batteries connected in series and in parallel ensure IO sufficient electric energy output so that the endurance capacity and operating efficiency of the power tools are improved. [0004] However, with the continuous development of battery pack technology, the discharge current and charge current of a battery pack increase gradually. During use, the heat generation of components of the battery pack through which the currents flow increases gradually. The 15 components include positive and negative terminal poles, circuit boards, and lead-out pieces connecting cells. Especially when a power tool keeps working for a while with a high current, the temperature on the components rises sharply, causing a problem about the safety and reliability of the battery pack. Additionally, the heat generation of the battery pack may shorten the life of the battery pack, raising the frequency for a user changing the battery pack and thus 20 increasing the cost of use. SUMMARY [0005] A battery pack is provided. The battery pack includes a housing, a battery pack interface enabling the battery pack to be detachably connected to a power tool, and a cell assembly located in the housing. The battery pack interface includes a battery pack positive 25 terminal and a battery pack negative terminal. The cell assembly includes a plurality of non-cylindrical cells. A cell includes a cell positive electrode and a cell negative electrode. The cell assembly includes a positive lead-out piece, a negative lead-out piece, a discharge path, and a protective element. The positive lead-out piece is connected in series between at least one cell 1 Date reyue/ date received 2022-01-25 positive electrode and the battery pack positive terminal. The negative lead-out piece 1s connected in series between at least one cell negative electrode and the battery pack negative terminal. The discharge path is configured to supply power to the power tool and consists of a cell assembly positive terminal, the positive lead-out piece, the battery pack positive terminal, a 5 cell assembly negative terminal, the negative lead-out piece, and the battery pack negative terminal. The protective element is disposed on the discharge path. In response to the discharge current of the discharge path being greater than or equal to a preset current, the protective element turns off to disconnect the discharge path. The length of one of the positive lead-out piece or the negative lead-out piece close to the protective element is greater than the length of IO the other of the positive lead-out piece or the negative lead-out piece away from the protective element. [0006] In one example, the protective element is connected between the positive lead-out piece and the battery pack positive terminal. The length of the positive lead-out piece close to the protective element is greater than the length of the negative lead-out piece away from the 15 protective element. [0007] In one example, the protective element is connected between the negative lead-out piece and the battery pack negative terminal. The length of the negative lead-out piece close to the protective element is greater than the length of the positive lead-out piece away from the protective element. 20 [0008] In one example, the cells are connected in series. [0009] In one example, the positive lead-out piece and the negative lead-out piece are made of metal. [0010] In one example, the cell assembly includes a first cell and a second cell. A positive electrode of the first cell is connected to a negative electrode of the second cell in series. The 25 positive lead-out piece is connected to a positive electrode of the second cell. The negative lead-out piece is connected to a negative electrode of the first cell. [0011] In one example, the discharge current of the battery pack is greater than or equal to 80 A. [0012] In one example, the capacity of the battery pack is greater than or equal to 5 Ah. 2 Date reyue/ date received 2022-01-25 [0013] In one example, the battery pack further includes a cell elastic piece disposed around the cell assembly. [0014] A battery pack is provided. The battery pack includes battery pack terminals, a plurality of non-cylindrical cells, two lead-out pieces, and a protective element. A cell includes a 5 cell output pole piece for outputting the electric energy of the cell. The two lead-out pieces are connected between the battery pack terminals and the cell output pole piece. The protective element is disposed between the battery pack terminals and the cell output pole piec