Patent Description:
As electric and electronic technology is developed, use of portable electronic products, which are small and light, and have various functions, is sharply increasing. A battery is generally used as a power supply device for operation of a portable electronic product, and a rechargeable battery, which is re-usable, is mainly used.

The rechargeable battery is a chargeable and dischargeable battery, unlike a primary battery that cannot be charged. The rechargeable battery is used in a portable small electronic device, such as a portable phone or a notebook computer, or is widely used as a power source for driving a motor of a power tool, a vehicle, and the like. An internal part of the rechargeable battery may be formed of a positive electrode, a negative electrode, a separation film, an electrolyte, and the like, and a case may be formed of a metal plate or a pouch.

A rechargeable battery having high energy density may cause a problem in safety, such as thermal runaway, and particularly, the case where the positive electrode and the negative electrode inside the rechargeable battery are shorted, so that the rechargeable battery is overheated is a representative example. The internal short is caused from a loss of a function of the separation film, and examples thereof include deformation by an external impact, metallic foreign substances included in a manufacturing process, and the forming of dendrite of lithium or copper by an electrochemical reaction.

In the related art, a technology of detecting a state of an internal short of a rechargeable battery in advance and preventing the internal short is developed. In the scheme in the related art, a check time of several tens of minutes or more is required in the state where a voltage of the rechargeable battery is very stable (no load or very low load). Accordingly, there is a disadvantage in that it is impossible to detect the internal short generated in the state where the rechargeable battery is continuously charged or discharged.

The above information is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.

The present invention has been made in an effort to provide a battery control apparatus and a method for detecting an internal short of a battery which are capable of preventing thermal runaway due to an internal short of a battery by effectively detecting the internal short of the battery.

An exemplary embodiment of the present invention provides a method for detecting an internal short of a battery, which may include: acquiring first charge state information related to a charge state of the battery; detecting a first reference time point when the first charge state information satisfies a reference condition; acquiring second charge state information related to the charge state of the battery; detecting a second reference time point when the second charge state information satisfies a reference condition; and detecting an internal short of the battery based on a difference between a charge amount from the first reference time point to the second reference time point and a discharge amount from the first reference time point to the second reference time point.

The detecting of the internal short may include determining that the internal short occurs in the battery when the difference between the charge amount and the discharge amount is equal to or more than a threshold value.

Each of the first charge state information and the second charge state information may include a state of charge (SOC) of the battery, and the reference condition may include a reference SOC.

The reference condition may include a full charge condition. In the exemplary embodiment, each of the first charge state information and the second charge state information may include a current value and a voltage value of the battery, respectively and the full charge condition may include a reference current value and a reference voltage value. Further, the detecting of the first reference time point may include detecting the first reference time point when the current value of the battery included in the first charge state information is equal to or less than the reference current value and the voltage value of the battery included in the first charge state information is equal to or more than the reference voltage value, and the detecting of the second reference time point may include detecting the first reference time point when the current value of the battery included in the second charge state information is equal to or less than the reference current value and the voltage value of the battery included in the second charge state information is equal to or more than the reference voltage value.

The method may further include determining whether the first charge state information and the second charge state information are similar to each other within a predetermined range, in which the detecting of the internal short may be performed and the voltage value of the battery included in the first charge state information is equal to or more than the reference voltage value, and the detecting of the second reference time point may include detecting the first reference time point when the current value of the battery included in the second charge state information is equal to or less than the reference current value and the voltage value of the battery included in the second charge state information is equal to or more than the reference voltage value.

The method may further include determining whether the first charge state information and the second charge state information are similar to each other within a predetermined range, in which the detecting of the internal short may be performed when the first charge state information and the second charge state information are similar to each other within the predetermined range.

The method further includes determining whether the charge amount and the discharge amount are equal to or more than a predetermined value, in which the detecting of the internal short may be performed when at least one of the charge amount and the discharge amount is equal to or more than the predetermined value.

The method may further include determining whether a time interval between the first reference time point and the second reference time point is within a threshold range, in which the detecting of the internal short may be performed when the time interval is within the threshold range.

The threshold range may be a maximum of <NUM> hours.

The method may further include: accumulating a charge current amount supplied from a charging device to the battery and a discharge current amount supplied from the battery to a load as the first reference time point is detected; and calculating the charge amount and the discharge amount based on the accumulated charge current amount and discharge current amount when the second reference time point is detected.

The method may further include resetting the accumulated charge current amount and discharge current amount after the calculating of the charge amount and the discharge amount.

Another exemplary embodiment of the present invention provides a battery control apparatus which includes: a measurement unit configured to measure a voltage, a current, and a temperature of the battery; a detector acquiring charge state information related to a charge state of the battery based on at least one of a voltage value, a current value, and a temperature value of the battery measured by the measurement unit and detecting reference time points when the charge state information satisfies a reference condition; an accumulator accumulating a charge current amount and a discharge current amount of the battery until a second reference time point is detected by the detector and calculating a charge amount and a discharge amount of the battery based on the accumulated charge current amount and discharge current amount; and an internal short detector detecting an internal short of the battery based on a difference between the charge amount from the first reference time point to the second reference time point and the discharge amount from the first reference time point to the second reference time point.

The internal short detector may determine that the internal short occurs in the battery when the difference between the charge amount and the discharge amount is equal to or more than a threshold value.

The charge state information includes an SOC of the battery, and the reference condition includes a reference SOC.

The reference condition may include a full charge condition. In the exemplary embodiment, the charge state information may include a current value and a voltage value of the battery and the full charge condition may include a reference current value and a reference voltage value. Further, the detector may detect the reference time point when the current value of the battery is equal to or less than the reference current value and the voltage value of the battery is equal to or more than the reference voltage value.

The internal short detector may detect the internal short based on the difference between the charge amount and the discharge amount when the charge state information of the battery at the first reference time point and the charge state information of the battery at the second reference time point are similar to each other within a predetermined range.

The internal short detector detects the internal short based on the difference between the charge amount and the discharge amount when the charge amount and the discharge amount are equal to or more than a predetermined value.

The internal short detector may detect the internal short based on the difference between the charge amount and the discharge amount when a time interval between the first reference time point and the second reference time point is within a threshold range.

According to an exemplary embodiment of the present invention, there is an effect in that an internal short of a battery can be effectively detected and thermal runaway of the battery can be prevented.

<FIG> is a flowchart illustrating a method for detecting an internal short of a battery of a battery control apparatus according to an exemplary embodiment of the present invention.

Hereinafter, a battery control apparatus according to an exemplary embodiment of the present invention will be described in more detail with reference to <FIG>.

<FIG> is a block diagram illustrating a configuration of a battery control apparatus according to an exemplary embodiment of the present invention and <FIG> is an equivalent circuit of a battery according to the exemplary embodiment of the present invention.

Referring to <FIG>, a battery control apparatus <NUM> according to an exemplary embodiment of the present invention may include a battery <NUM>, a measurement unit <NUM>, a detection unit <NUM>, and a control unit <NUM> and may prevent thermal runaway of the battery by sensing the internal short of the battery <NUM>.

The battery <NUM> as a secondary battery which is chargeable and dischargeable may be referred to as a cell.

Referring to <FIG>, the battery <NUM> may include two terminals B+ and B- and may be charged by an external charging device (not illustrated) or discharged by an external load (not illustrated) through the two terminals B+ and B-. For convenience of the description, it is described that the charging device is provided outside the battery control device <NUM>, but the exemplary embodiment of the present invention is not limited thereto.

As illustrated in <FIG>, the battery <NUM> may include an internal resistance RB, and the internal resistance RB may have a resistance value of several mΩ to several hundreds of mΩ. When an internal short is generated in the battery <NUM>, the same effect as an effect in that a switch S inside the battery <NUM> is electrically connected is generated.

When the switch S is electrically connected, a short current Ishort flows in a short resistance Rs, so that the battery <NUM> is discharged. In this case, the short resistance Rs may have a resistance value of a broad range of several mΩ to several kΩ.

The battery <NUM> is charged by one or more charging methods among constant current (CC) charging, in which the battery is charged with a constant current from an initial stage to a completion stage of the charging, constant voltage (CV) charging, in which the battery is charged with a constant voltage from an initial stage to a completion state of the charging, and CC-CV charging, in which the battery is charged with a constant current at an initial stage of the charging and is charged with a constant voltage at a completion stage of the charging. The CC charging is a charging method for supplying constant current to the battery <NUM> and charging the battery <NUM> until the battery <NUM> reaches a predetermined set voltage. The voltage of the battery <NUM> may be raised together with the charge amount of the battery <NUM> while the CC charging is performed. In the present specification, the charge amount indicates the amount of electric charge (or capacity) that a charging device (not illustrated) supplies to the battery <NUM> to charge the battery <NUM>, and is different from a state of charge (SOC) indicating a charge level. Further, the discharge amount means the amount of electric charge supplied from the battery <NUM> to a load (not illustrated).

When the charging and discharging of the battery <NUM> are repeated under the same condition, a charge amount between fully charged time points of the battery <NUM>, that is, until the battery <NUM> is fully charged again, after the battery <NUM> is fully charged and then discharged is slightly larger than the discharge amount. Such a difference is due to various energy losses including heat generation, self-discharge, etc., of the battery <NUM> during the progress of charging/discharging.

When the internal short occurs in the battery <NUM>, the short current Ishort is generated as illustrated in <FIG> and this causes energy loss by the short resistance Rs in the battery. Therefore, when the internal short occurs in the battery <NUM>, the amount of electric charge (discharge amount) which the battery <NUM> may supply to the load (not illustrated) compared with the amount of electric charge (charge amount) which the charging device (not illustrated) may supply to the battery <NUM> is significantly smaller than that at before the internal short occurs. That is, in the battery <NUM> in which the internal short occurs, some of the amount of electric charge (charge amount) supplied by the charging device for charging the battery <NUM> during charging is consumed by an internal short path including the short resistance Rs, the amount of electric charge actually accumulated in the battery <NUM> compared with the amount of electric charge supplied from the charging device is smaller than that before the internal short occurs. Further, in the battery <NUM> in which the internal short occurs, energy is consumed by the internal short path including the short resistance Rs at the time of discharging, and as a result, the amount of electric charge supplied from the battery <NUM> to the external load compared with the amount of electric charge actually discharged by the battery <NUM> is smaller than that before the internal short occurs.

Referring to such a characteristic, the battery control apparatus <NUM> according to the exemplary embodiment monitors the charge amount and the discharge amount of the battery <NUM> to detect the internal short of the battery <NUM>. A detailed configuration of detecting the internal short of the battery <NUM> by monitoring the charge amount and the discharge amount of the battery <NUM> will be described below.

The measurement unit <NUM> continuously measures a voltage V, a current I, and a temperature T of the battery <NUM> and transfers the measured voltage value, current value, temperature value to the detection unit <NUM>. In the present specification, the current I of the battery <NUM> indicates charge current supplied from a charging device (not illustrated) to the battery <NUM> or discharge current supplied from the battery <NUM> to an external load (not illustrated).

The detection unit <NUM> includes a detector <NUM>, an accumulator <NUM>, and an internal short detector <NUM> and monitors the charge amount and the discharge amount of the battery <NUM> and detects the internal short of the battery <NUM>, and generates a short detection signal Ds.

The detector <NUM> acquires charge state information related to a charge state of the battery <NUM> from a temperature value, a voltage value, and a current value of the battery <NUM> received from the measurement unit <NUM> at the time of charging the battery <NUM>. Here, the charge state information may include a temperature value, a voltage value, and a current value of the battery <NUM> measured by the measurement unit <NUM>, or may include an SOC of the battery <NUM>.

Further, the detector <NUM> detects a time point (hereinafter, referred to as a 'reference time point') when the charge state information of the battery <NUM> satisfies a predetermined reference condition.

In the detector <NUM>, a reference condition used for detecting the reference time point may include a reference SOC. In this case, the detector <NUM> may detect a time point when the SOC of the battery <NUM> reaches a predetermined reference SOC as the reference time point. The reference SOC may be an SOC which becomes a reference for determining that the battery <NUM> is in a full charge state, but the exemplary embodiment is not limited thereto, and as a result, the reference SOC may be set to a value which is lower or higher than the SOC which becomes the reference for determining the full charge state.

In the detector <NUM>, the reference condition used for detecting the reference time point as a full charge condition of the battery <NUM> may include at least one condition for determining the full charge state of the battery <NUM>.

As one example, the reference condition may include a reference voltage value and a reference current value for determining the full charge state of the battery <NUM>. In this case, the detector <NUM> may detect a time point when the voltage value of the battery <NUM> is equal to or more than a reference voltage value and the current value of the battery <NUM> is equal to or less than a reference current value as the reference time point. The full charge condition may include other conditions other than the reference voltage value and the reference current value and this may vary depending on a scheme in which the battery control apparatus <NUM> determines the full charge state of the battery <NUM>.

In the detector <NUM>, the reference condition used for detecting the reference time point may include a reference voltage value and a reference current value for determining a predetermined state other than the full charge state of the battery <NUM>. In this case, the reference voltage value and the reference current value may correspond to a voltage value and a current value which become a reference for determining whether the battery <NUM> reaches a predetermined charge state before or after the battery <NUM> reaches the full charge state. In this case, the detector <NUM> may detect a time point when the voltage value of the battery <NUM> is equal to or more than the reference voltage value and the current value of the battery <NUM> is equal to or less than the reference current value as the reference time point similarly to the detection of the full charge state.

The accumulator <NUM> accumulates the charge amount and the discharge amount of the battery <NUM> until a subsequent reference time point is detected when the reference time point is detected by the detector <NUM> to calculate the charge amount and the discharge amount of the battery <NUM> during a period (hereinafter, referred to and used as a 'comparison period') between both reference time points. Here, the accumulator <NUM> may accumulate charge current supplied from the charging device to the battery <NUM> during the comparison period and acquire the charge amount during the comparison period from the accumulated charge current amount and accumulate discharge current supplied from the battery <NUM> to the external load during the comparison period and acquire the discharge amount during the comparison period from the accumulated discharge current amount.

In such a scheme, the accumulator <NUM> may calculate the charge amount and the discharge amount for each of a plurality of comparison periods with two different reference time points as a start reference time point and an end reference time point, respectively. To this end, the accumulator <NUM> is reset when the reference time point is detected to reset the charge current amount and the discharge current amount accumulated during the previous comparison period and newly start accumulation of the charge current and the discharge current. The start reference time point of each comparison period may be the same as the end reference time point of the previous comparison period and the end reference time point may be the same as the start reference time point of the subsequent comparison period.

The accumulator <NUM> may be a single accumulator having a sign and may include two accumulators for accumulating the charge current amount and the discharge current amount, respectively, but the exemplary embodiment is not limited thereto. When the charge amount and the discharge amount during each comparison period are calculated by the accumulator <NUM>, the internal short detector <NUM> detects the internal short IS of the battery <NUM> based on the calculated charge amount and discharge amount and transfers a detection signal Ds including information on whether the internal short IS occurs to the control unit <NUM>.

The control unit <NUM> may control connection or disconnection of an external charging apparatus (not illustrated) or a load (not illustrated) connected to the battery <NUM> based on the detection signal Ds received from the internal short detector <NUM>. For example, the control unit <NUM> may interrupt the connection of the external charging apparatus (not illustrated) or the load (not illustrated) connected to the battery <NUM> when the detection signal Ds indicating the occurrence of the internal short of the battery <NUM> is generated by the internal short detector <NUM>.

Accordingly, the battery control apparatus <NUM> may detect the internal short of the battery <NUM> and control the connection between the battery <NUM> and a charging apparatus (or load) according to a detection result of the internal short, thereby preventing thermal runaway of the battery <NUM> due to the internal short.

As described above, when the internal short of the battery <NUM> is to be detected by comparing the charge amount and the discharge amount of the battery <NUM> during a comparison period having a start reference time point and an end reference time point, the amount of electric charge (or SOC) held by the battery <NUM> at the start reference time point of the comparison period and the amount of electric charge (or SOC) held by the battery <NUM> at the end reference time point need to be equal to each other or similar to each other at a predetermined level or higher. This is because the difference between the amount of electric charge held by the battery <NUM> at the start reference time point of the comparison period and the amount of electric charge held by the battery <NUM> at the end reference time point of the comparison period influences the difference between the charge amount and the discharge amount of the battery <NUM> during the comparison period in addition to the internal short, and as a result, it is difficult to detect the internal short by comparing the charge amount and the discharge amount.

Therefore, the battery control apparatus <NUM> sets a reference condition so as to detect a time when the charge state of the battery <NUM> reaches a state (for example, a full charge state) in which the amount of electric charge held by the battery <NUM> is determined to have a predetermined value consistently with the start reference time point and the end reference time point of the comparison period.

In addition, when the internal short detector <NUM> determines the charge state of the battery <NUM> at the start reference time point and the charge state of the battery <NUM> at the end reference time point for one comparison period are different from each other at a predetermined level or higher due to a change in surrounding environment of the battery <NUM>, the internal short detector <NUM> may omit detection of the internal short. For example, when the full charge condition for determining the full charge state of the battery <NUM> is set to be changed in accordance with the change of the surrounding environment such as a temperature, etc., the full charge conditions at the start reference time point and the end reference time point for one comparison period may be different from each other. Accordingly, the internal short detector <NUM> compares charge state information (e.g., a voltage value, a current value, a temperature value, etc.) of the battery <NUM> at the start reference time point of the comparison period and charge state information (e.g., the voltage value, the current value, the temperature value, etc.) at the end reference time point with each other to determine whether to detect the internal short.

Further, the internal short detector <NUM> detects the internal short by comparing the charge amount and the discharge amount only when at least one of the charge amount and the discharge amount generated during the comparison period is equal to or greater than a predetermined value. This is because, if the charge amount and the discharge amount during the comparison period are too small, the difference between the charge amount and the discharge amount due to the internal short is insignificant, and the reliability of the internal short detection is lowered.

Further, the internal short detector <NUM> compares the charge amount and the discharge amount with each other to detect the internal short only when the length of the comparison period, that is, a time interval between the start reference time point and the end reference time point of the comparison period is within a predetermined threshold range. This is to prevent detection reliability from being lowered due to detection of the internal short in a situation in which information of the accumulator <NUM> because the time interval between the start reference time point and the end reference time point is too short so that the difference between the charge amount and the discharge amount due to the internal short is insignificant or the time interval between the start reference time point and the end reference time point is too long so that the information of the accumulator <NUM> may not be reliable. Therefore, the internal short detector <NUM> sets a threshold range so as to set a minimum time for generating the difference between the charge amount and the discharge amount due to the internal short to a detectable level as a minimum value and set a maximum time for securing the reliability of the accumulator <NUM> to a predetermined level or higher as a maximum value and compares the charge amount and the discharge amount to detect the internal short by comparing the charge amount and the discharge amount only when the length (the time interval between the start reference time point and the end reference time point) of the comparison period is within a threshold range. The threshold range may be set to a minimum of <NUM> hours within a maximum of <NUM> hours, but the exemplary embodiment is not limited thereto.

Hereinafter, a method for detecting the internal short IS of the battery <NUM> by the battery control apparatus <NUM> will be described with reference to <FIG>.

<FIG> is a graph schematically showing changes in a charge amount and a discharge amount depending on occurrence of an internal short of a battery <NUM>, and illustrates a case where the battery <NUM> is repeatedly charged and discharged by a CC-CV charging method and a CC discharging method as an example.

In the graphs of <FIG>, t denotes time, I denotes a charge current supplied from the charging device to the battery <NUM> or a discharge current supplied from the battery <NUM> to the load, and C denotes a charge amount or a discharge amount. Referring to <FIG>, the charge amount of the battery <NUM> continuously increases while the charge current is supplied to the battery <NUM>, and the discharging amount of the battery <NUM> continuously increases while the discharging current is supplied from the battery <NUM>.

In <FIG> as an example, the detector <NUM> acquires information on the charge state of the battery <NUM> using the information obtained through the measurement unit <NUM>, and detects a plurality of time points when the charge state information of the battery <NUM> satisfies the full charge condition as reference time points t1, t2, t3, and t4. Further, the detector <NUM> stores the information on the charge state of the battery <NUM> at the corresponding time point in a memory (not shown) whenever the reference time points t1, t2, t3, and t4 are detected.

When the reference time points t1, t2, t3 and t4 are detected, the accumulator <NUM> calculates charge amounts cc1, cc2, and cc3 and discharge amounts dc1, dc2, and dc3 with respect to a plurality of comparison periods p1, p2, and p3 which set each of the reference time points t1, t2, t3, and t4 as a start reference time point or an end reference time point. The accumulator <NUM> may calculate the charge amount and the discharge amount during each of the comparison periods p1, p2, and p3 by accumulating the charge current and the discharge current for each of the plurality of comparison periods p1, p2, and p3.

Specifically, when the reference time point t1 is detected, the accumulator <NUM> then accumulates each of the charge current amount and the discharge current amount until the reference time point t2 is detected. In addition, when the reference time point t2 is detected, the charge amount cc1 and the discharge amount dc1 of the comparison period p1 are calculated from the charge current amount and the discharge current amount accumulated from the reference time point t1 to the reference time point t2. Further, the charge current amount and the discharge current amount accumulated so far are reset, and the charge current amount and the discharge current amount are then respectively accumulated until the reference time point t3 is detected after the start of new accumulation.

In addition, when the reference time point t3 is detected, the charge amount cc2 and the discharge amount dc2 of the comparison period p2 are calculated from the charge current amount and the discharge current amount accumulated from the reference time point t2 to the reference time point t3. Further, the charge current amount and the discharge current amount accumulated so far are reset, and the charge current amount and the discharge current amount are then respectively accumulated until the reference time point t4 is detected after the start of new accumulation.

In addition, when the reference time point t4 is detected, the charge amount cc3 and the discharge amount dc3 of the comparison period p3 are calculated from the charge current amount and the discharge current amount accumulated from the reference time point t3 to the reference time point t4.

In this scheme, the internal short detector <NUM> compares the calculated charge amount and discharge amount each time the charge amount and the discharge amount in each of the comparison periods p1, p2, and p3 are calculated and when the difference between the charge amount and the discharge amount is equal to or more than the threshold value, it is determined that the internal short occurs. In addition to the internal short, the energy of the battery <NUM> is lost due to heat generation or the like while the charging/discharging of the battery <NUM> is in progress. However, the amount of energy lost in this case is insignificant and may be ignored by setting a threshold value appropriately when detecting the internal short. That is, the battery control apparatus <NUM> sets the threshold value used for internal short detection to a predetermined value or more so that it is erroneously determined that the energy loss due to factors other than the internal short is not occurs due to the internal short.

Taking <FIG> as an example, the comparison period p1 is a period before the internal short occurs, and the charge amount and the discharge amount during the comparison period p1 are very similar to each other.

Thereafter, the internal short occurs during the charging of the battery <NUM> in the comparison period p2, so that the charge amount cc2 in the comparison period p2 is larger than the charge amount cc1 in the comparison period p1 in which the battery <NUM> is in a normal state. Therefore, a difference d1 between the discharge amount dc2 and the charge amount cc2 during the comparison period p2 becomes equal to or larger than a threshold value and the internal short of the battery <NUM> may be detected by the internal short detector <NUM>.

Thereafter, in the comparison period p3, charging and discharging are performed in a state in which the internal short occurs, so that the energy loss due to the internal short further increases. Accordingly, a difference d2 between the discharge amount dc3 and the charge amount cc3 during the comparison period p3 increases as compared with the difference during the previous comparison period p2. Thus, the internal short of the battery <NUM> is once again detected by the internal short detector <NUM>.

In the battery control apparatus <NUM> described above, the measurement unit <NUM>, the detection unit <NUM>, or the control unit <NUM> may be performed by one or more central processing units (CPUs) or a processor implemented by other chipsets, microprocessors, etc..

Hereinafter, a battery control method according to an exemplary embodiment of the present invention will be described with reference to <FIG>.

<FIG> is a flowchart illustrating a method for detecting an internal short according to an exemplary embodiment of the present invention.

The method for detecting the internal short in <FIG> may be performed by the battery control apparatus <NUM> described with reference to <FIG> and <FIG>.

Referring to <FIG>, the detection unit <NUM> acquires the charge state information of the battery <NUM> (S10) and compares the charge state information with a reference condition to determine whether the reference time point when the charge state information of the battery <NUM> satisfies the reference condition (S11).

In step S10, the detection unit <NUM> receives results of measuring voltage, current, and a temperature of the battery <NUM> from the measurement unit <NUM> and acquires the charge state information related to a charge state of the battery <NUM> from the measurement results. Here, the charge state information may include a temperature value, a voltage value, and a current value of the battery <NUM> measured by the measurement unit <NUM>, or may include an SOC of the battery <NUM>.

In step S11, a reference time point is used as a start time point or an end time point of a comparison period, and the reference condition for detecting the reference time point may include a reference SOC, a full charge condition, or a reference voltage value and a reference current value.

The detection unit <NUM> repeatedly performs step S10 of acquiring the charge state information of the battery <NUM> until the reference time point is detected and step S11 of determining whether the reference time point is detected by comparing the charge state information with the reference condition. In addition, when the reference time point is detected through step S11, the detection unit <NUM> accumulates the charge current amount supplied from a charging device to the battery <NUM> and the discharge current amount supplied from the battery <NUM> to a load (S12). Further, the detection unit <NUM> acquires the charge state information of the battery <NUM> (S13) and determines whether the reference time point when the charge state information of the battery <NUM> satisfies the reference condition is detected by comparing the acquired charge state information with the reference condition (S14).

The detection unit <NUM> repeatedly performs step S12 of accumulating the charge current amount and the discharge current amount until the reference time point is detected, step S13 of acquiring the charge state information of the battery <NUM>, and step S14 of determining whether the reference time point is detected by comparing the charge state information with the reference condition. In addition, when the reference time point is detected through step S14, the charge amount and the discharge amount of the battery <NUM> are calculated by using the charge current amount and the discharge current amount accumulated so far (S15). In addition, the charge current amount and the discharge current amount accumulated so far are reset by resetting the accumulator <NUM> (S16).

In step S15, the charge current amount and the discharge current amount accumulated from the reference time point detected through step S11 to the reference time point detected through step S14 are used in order to calculate the charge amount and the discharge amount. That is, in this case, in the comparison period in which the charge amount and the discharge amount are calculated, the start time point may become a reference time point detected through step S11 and the end time point may become a reference time point detected through step S14.

On the other hand, before detecting the internal short of the battery <NUM> by comparing the charge amount and the discharge amount in the comparison period, the detection unit <NUM> first checks whether a current situation is a state in which the internal short detection is possible in order to secure the detection reliability (S17). In addition, if it is determined that the current state is a state in which the internal short detection is possible, the charge amount and the discharge amount in the comparison period are compared and the process proceeds to step S18 for performing the internal short detection.

For example, the detection unit <NUM> checks in step S17 whether the charge state information (e.g., a voltage value, a current value, a temperature value, etc.) of the battery <NUM> at the time of detecting the reference time point through step S11 and the charge state information (e.g., the voltage value, the current value, the temperature value, and the like) of the battery <NUM> at the time of detecting the reference time point through S14 are similar to each other at a predetermined level or more and if both charge state information is similar at a predetermined level or more, the process may proceed to step S18. Specifically, the detection unit <NUM> may determine that the charge state information of the battery <NUM> at two reference time points is similar when the difference between the temperature value of the battery <NUM> at the reference time point detected through step S11 and the temperature value of the battery <NUM> at the reference time point detected through step S14 is equal to or less than a predetermined value, the difference between the current value of the battery <NUM> at the reference time point detected through step S11 and the current value of the battery <NUM> at the reference time point detected through step S14 is equal to or less than a predetermined value, and the difference between the voltage value of the battery <NUM> at the reference time point detected through step S11 and the voltage value of the battery <NUM> at the reference time point detected through step S14 is equal to or less than a predetermined value Further, for example, in step S17, the detection unit <NUM> may check whether at least one of the charge amount and the discharge amount from the reference time point detected through step S11 to the reference time point detected through step S14 is equal to or greater than a predetermined value and when at least one of the charge amount and the discharge amount is equal to or greater than the predetermined value, the process may proceed to step S18.

Further, for example, in step S17, the detection unit <NUM> may compare the length of the comparison period in which the reference time point detected through step S11 is set as the start time point and the reference time point detected through step S14 is set as the end time point with a threshold range (e.g., from a minimum of <NUM> hours to a maximum of <NUM> hours) and if the length of the comparison period is within the threshold range, the process may proceed to step S18.

In step <NUM>, if all the conditions listed above as an example are satisfied, the detection unit <NUM> may proceed to step S18 of performing the internal short detection by comparing the charge amount and the discharge amount in the comparison period. However, since the exemplary embodiment is not limited thereto, even if only some of the conditions listed above as an example are satisfied, the detection unit <NUM> may proceed to step S18 of performing the internal short detection by comparing the charge amount and the discharge amount in the comparison period.

Step S17 described above is to prevent the internal short detection from being performed in a situation in which the difference between the charge amount and the discharge amount calculated during the comparison period increases to a threshold value or more due to factors other than the internal short, the internal short detection from being performed in a situation in which the difference between the charge amount and the discharge amount by the internal short is not generated to the detectable level, or the internal short detection from being performed in a situation in which the reliability of the calculated charge amount and discharge amount is low.

When it is determined that a current situation is not a situation in which the internal short detection is possible through step S17, the detection unit <NUM> proceeds to step S12 to initiate accumulation of the charge current amount and the discharge current amount in a new comparison period. In this case, the reference time point previously detected through step S14 becomes the start time point of the new comparison period and the reference time point detected later becomes the end time point of the new comparison period.

If it is determined in step S17 that the current situation is a situation in which the internal short detection is possible, the detection unit <NUM> determines whether the difference between the charge amount and the discharge amount from the reference time point detected through step S11 to the reference time point detected through step S14 is equal to or more than the threshold value (S18). In addition, when the difference between the charge amount and the discharge amount is equal to or more than a threshold value, it is determined that the internal short occurs in the battery <NUM> (S19) and connection between the battery <NUM> and the charging device (not illustrated) or between the battery <NUM> and the load is blocked (S20) to prevent thermal runaway of the battery <NUM>.

Claim 1:
A method for detecting an internal short of a battery (<NUM>), the method comprising:
acquiring first charge state information related to a charge state of the battery (<NUM>);
detecting a first reference time point when the first charge state information satisfies a reference condition;
acquiring second charge state information related to the charge state of the battery (<NUM>);
detecting a second reference time point when the second charge state information satisfies the reference condition;
determining whether at least one of a charge amount from the first reference time point to the second reference time point and a discharge amount from the first reference time point to the second reference time point is equal to or more than a predetermined value; and
detecting an internal short of the battery (<NUM>) based on a difference between the charge amount and the discharge amount,
wherein the detecting of the internal short is performed when at least one of the charge amount and the discharge amount is equal to or more than the predetermined value,
wherein the charge amount is an amount of electric charge that a charging device supplies to the battery (<NUM>) to charge the battery (<NUM>),
the discharge amount is an amount of electric charge supplied from the battery (<NUM>) to a load, and
wherein:
each of the first charge state information and the second charge state information includes a state of charge, SOC, of the battery (<NUM>), and
the reference condition includes a reference SOC.