TWM649779U - Battery module - Google Patents

Abstract

A battery module is provided. The battery module includes a battery cell pack and a control circuit. The battery cell pack includes a plurality of battery cells. The control circuit is configured to detect impedance values of the plurality of battery cells. When a change trend of the impedance value of one of the plurality of battery cells turns negative, the control circuit makes the battery module enter a permanent fail state.

Description

battery module

This new invention relates to a battery module that can reduce the risk of micro-short circuits or short circuits.

In today's handheld electronic products, such as laptops, mobile phones, digital cameras or tablets, batteries play an important role in providing power. However, when a battery experiences a micro-short circuit or even a short circuit, it often causes battery voltage imbalance or the risk of fire, which may lead to serious safety issues.

This new invention provides a battery module, including a battery core group and a control circuit. The battery cell pack includes a plurality of battery cells. The control circuit is coupled to the battery cell group and used to detect the impedance values of the plurality of battery cells. When the change trend of the impedance value of one of the plurality of battery cells turns negative, the control circuit causes the battery module to enter a permanent failure state.

Based on the above, the battery module created by the present invention can monitor the short circuit phenomenon of the battery module through the impedance value of the battery cell. In this way, the battery module can enter a permanent failure state before a serious micro-short circuit or short circuit occurs, thereby maintaining the safety of the battery module and thus avoiding hazardous safety issues.

In order to make the above-mentioned features and advantages of this case more obvious and easy to understand, embodiments are given below and explained in detail with the accompanying drawings.

Referring to FIG. 1 , the battery module 100 of this embodiment is suitable for handheld electronic products such as notebook computers, mobile phones, digital cameras, and tablet computers. The battery module 100 includes a battery core group 110 and a control circuit 120 .

The battery cell group 110 includes n battery cells (battery cell cells) BC0 to BCn-1. n is a positive integer greater than 1. The control circuit 120 is, for example, a battery gauge chip (Battery gauge IC) or a microcontroller (Microcontroller). The control circuit 120 is coupled to the battery cell group 110 and can be used to control the battery cell group 110 and grasp the status of the battery cells BC0 ~ BCn-1 and the battery module 100 . For example, the control circuit 120 can be used to detect the impedance values of the battery cells BC0~BCn-1, detect the internal temperature of the battery module 100, detect the stored power of the battery module 100, etc.

The control circuit 120 can load the stored firmware to execute the battery protection method of the present invention. The detailed steps of the battery protection method of the present invention are described below with examples. Please refer to Figure 1 and Figure 2 at the same time. The battery protection method of this embodiment can be applied to the battery module 100 of Figure 1. The steps are described as follows:

First, in step S200, the control circuit 120 determines whether the battery protection function is turned on. The battery protection function is mainly aimed at the battery protection method described in this new creation to avoid micro short circuits or short circuits. For example, the control circuit 120 can determine whether the battery protection function is enabled according to the settings in the firmware. When the battery protection function is not turned on, the control circuit 120 will continue to determine whether the battery protection function is turned on until the battery protection function is turned on.

When the battery protection function is enabled, in step S202, the control circuit 120 detects the internal temperature of the battery module 100 and determines whether the internal temperature of the battery module 100 is within a preset temperature range. The temperature range in this embodiment is, for example, a temperature range between 20 degrees Celsius and 45 degrees Celsius, but the invention is not limited to this. When the internal temperature of the battery module 100 is not within the preset temperature range, the control circuit 120 will continue to detect the internal temperature of the battery module 100 until the internal temperature of the battery module 100 is within the preset temperature range.

When the internal temperature of the battery module 100 is within the preset temperature range, in step S204, the control circuit 120 detects the impedance values of the battery cells BC0~BCn-1, and determines the impedance values of the battery cells BC0~BCn-1. Whether the change trend of any impedance value turns negative (gets smaller and smaller). Specifically, under normal circumstances, with the accumulation of use time, the changing trend of the impedance value of the battery cell will be positive (increasingly larger). If the change trend of the impedance value of the battery cell is negative, abnormal conditions such as micro short circuit or short circuit may occur. Table 1 below records 15 detection points and their corresponding power values as an example. detection point Electricity value (RSOC %) 1 100 2 89 3 78 4 67 5 56 6 45 7 34 8 twenty three 9 20 10 17 11 14 12 11 13 8 14 5 15 2 Table 1

The control circuit 120 may select one or more power values within a preset power range (eg, 70% to 40%) in Table 1 as the representative power level (eg, select 67% as the representative power level). Since the control circuit 120 can grasp the stored power of the battery module 100 in real time, whenever the stored power of the battery module 100 drops below one or more representative powers, the control circuit 120 detects and records the current battery cells BC0~BCn- impedance value of 1.

The initial value of the negative count value corresponding to each battery cell BC0~BCn-1 is set to 0. After recording the current impedance value of the battery cells BC0 ~ BCn-1, the control circuit 120 can compare the impedance value of each battery cell BC0 ~ BCn-1 recorded this time with the previously recorded impedance value of each battery cell BC0 ~ BCn. -1 impedance value for comparison.

When the impedance value of one of the battery cells BC0 ~ BCn-1 recorded this time is smaller than the impedance value of the same battery cell recorded previously, the control circuit 120 can increment the negative count value corresponding to the battery cell. (That is, add 1 to the negative count value).

The control circuit 120 can count the negative count value corresponding to each battery cell BC0~BCn-1. When the negative count value corresponding to one of the battery cells BC0 ~ BCn-1 is greater than the threshold value (for example, 1), it means that the impedance value of this battery cell has been reduced multiple times. At this time, the control circuit 120 may determine that the variation trend of the impedance value of the battery cell has turned negative.

In one embodiment, when the impedance value of one of the battery cells BC0 ~ BCn-1 recorded this time is not smaller than the impedance value of the same battery cell recorded previously, the control circuit 120 can place the battery cell to The corresponding negative count value is restored to the initial value. In this way, it is necessary for the control circuit 120 to determine that the change trend of the corresponding battery cell's impedance value has turned to a negative direction only when the impedance value decreases occur multiple times in a row, thereby reducing the chance of misjudgment.

When the variation trend of the impedance value of any of the battery cells BC0 ~ BCn-1 turns negative, then return to step S202 to continue the judgment.

When the change trend of the impedance value of one of the battery cells BC0~BCn-1 turns negative, it means that this battery cell may be slightly short-circuited or short-circuited. At this time, in step S206, the control circuit 120 causes the battery module 100 to enter a permanent failure (PF) state to implement a battery protection mechanism in real time.

To sum up, the battery module created by this new invention can monitor the short circuit phenomenon of the battery module according to the changing trend of the impedance value of the battery cell. In this way, the battery module can enter a permanent failure state before a serious micro-short circuit or short circuit occurs, thereby maintaining the safety of the battery module and thus avoiding hazardous safety issues.

100:battery module 110:Battery core pack 120:Control circuit BC0, BC1, BCn-1: battery cells S200, S202, S204, S206: steps

FIG. 1 is a block diagram of a battery module according to an embodiment of the present invention. FIG. 2 is a flow chart of a battery protection method according to an embodiment of the present invention.

100:battery module

110:Battery core pack

120:Control circuit

BC0, BC1, BCn-1: battery cells

Claims (10)

A battery module including: a battery cell pack including a plurality of battery cells; and a control circuit coupled to the battery cell group for detecting the impedance values of the battery cells, Wherein, when a changing trend of the impedance value of one of the battery cells turns negative, the control circuit causes the battery module to enter a permanent failure state. The battery module of claim 1, wherein each time a stored power of the battery module drops below one or more representative powers, the control circuit detects and records the current impedance values of the battery cells. The battery module as described in claim 2, wherein the representative charge or batteries are within a range of 70% to 40%. The battery module as described in claim 2, wherein the initial value of a negative count value corresponding to each of the battery cells is set to 0, and the control circuit changes the impedance value of each of the battery cells recorded this time. Compare with the impedance values of each battery cell recorded last time, When the impedance value of one of the battery cells recorded this time is smaller than the impedance value of the same battery cell recorded previously, the control circuit changes the negative direction corresponding to one of the battery cells. The count value is incremented. The battery module as claimed in claim 4, wherein the control circuit counts the negative count values corresponding to each of the battery cells, When the negative count value corresponding to one of the battery cells is greater than a threshold value, the control circuit determines that the changing trend of the impedance value of one of the battery cells turns negative. The battery module as described in claim 4, wherein when the impedance value of one of the battery cells recorded this time is not smaller than the impedance value of the same battery cell recorded previously, the control circuit will The negative count value corresponding to one of the battery cells is restored to the initial value. The battery module of claim 1, wherein the control circuit detects an internal temperature of the battery module and determines whether the internal temperature of the battery module is within a temperature range, When the temperature of the battery module is within the temperature range, the control circuit detects the impedance values of the battery cells. The battery module as claimed in claim 7, wherein the temperature range is a temperature range between 20 degrees Celsius and 45 degrees Celsius. The battery module as described in claim 1, wherein the control circuit determines whether a battery protection function is turned on, When the battery protection function is turned on, the control circuit detects the impedance values of the battery cells. The battery module of claim 1, wherein the control circuit is a battery metering chip or a microcontroller.

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