Patent Description:
The present disclosure relates to a battery management apparatus and method, and more particularly, to a battery management apparatus and method capable of improving the performance efficiency of a battery.

In addition, recently, in order to achieve various goals such as high capacity and high output of the battery, research on negative electrode active material in which two or more materials are mixed is being conducted. However, since two or more materials have different charge/discharge efficiencies and different reaction voltage ranges from each other, battery degradation issues arise due to rapid degradation of a material with relatively low charge/discharge efficiency. Therefore, for a battery including a negative electrode active material in which two or more kinds of materials are mixed, it is necessary to prepare a way to increase the lifespan.

<CIT> discloses a battery management device, which comprises: a voltage measuring unit which measures a voltage when a battery cell is discharged, and measures an open circuit voltage of the battery cell whenever the measured voltage reaches a reference discharge voltage; and a control unit which is configured to receive the open circuit voltage measured by the voltage measuring unit, calculate a voltage fluctuation rate by comparing the received open circuit voltage with a pre-stored reference voltage, determine a voltage increase/decrease pattern based on the calculated voltage fluctuation rate and pre-stored voltage fluctuation rate data, determine a first degree of deterioration acceleration of the battery cell in accordance with the determined voltage increase/decrease pattern, and change a preset control condition based on the received open circuit voltage and the determined first degree of deterioration acceleration.

The present disclosure is designed to solve the problems of the related art, and therefore the present disclosure is directed to providing a battery management apparatus and method capable of increasing the performance efficiency and lifespan of a battery by adjusting a discharge termination voltage of the battery.

A battery management apparatus according to the invention comprises:
a measuring unit configured to measure a voltage of a battery after discharge of the battery is terminated to a preset discharge termination voltage in every cycle; and a control unit configured to receive voltage information of the battery from the measuring unit in every cycle, calculate a first voltage deviation of the battery based on a preset first criterion voltage and the voltage of the battery, calculate a second voltage deviation between the first voltage deviation and a preset second criterion voltage in each cycle, and adjust the discharge termination voltage based on a criterion deviation set to correspond to a current cycle and the second voltage deviation calculated in the current cycle.

The control unit may be configured to determine a cycle region to which the current cycle belongs among a plurality of preset cycle regions, and adjust the discharge termination voltage based on a criterion deviation set for the determined cycle region and the calculated second voltage deviation.

The control unit may be configured to increase the discharge termination voltage, when the calculated second voltage deviation is equal to or greater than the criterion deviation.

The plurality of cycle regions may be set based on a capacity retention rate of each cycle for a reference cell corresponding to the battery.

The control unit may be configured to obtain a capacity profile representing a corresponding relationship between a cycle and a capacity for a reference cell corresponding to the battery, and classify and set a plurality of cycles included in the capacity profile into a plurality of cycle regions according to a capacity change rate for the cycle.

The control unit may be configured to set the criterion deviation for each of the plurality of cycle regions, so that the criterion deviation corresponding to a first cycle region among the plurality of cycle regions is lower than the criterion deviation corresponding to the remaining cycle regions.

After the discharge termination voltage is changed, the control unit may be configured to change the second criterion voltage to the first voltage deviation corresponding to a cycle after the discharge termination voltage is changed.

The measuring unit may be configured to measure a rest voltage of the battery and transmit the rest voltage as the voltage information of the battery, after a predetermined time elapses from the termination of discharge of the battery.

The control unit may be configured to calculate the first voltage deviation by computing a difference between the rest voltage and the first criterion voltage.

A battery pack comprising the battery management apparatus is also provided.

A battery management method according to the invention comprises: a voltage measuring step of measuring a voltage of a battery after discharge of the battery is terminated to a preset discharge termination voltage in every cycle; a first voltage deviation calculating step of calculating a first voltage deviation of the battery based on a preset first criterion voltage and the voltage of the battery; a second voltage deviation calculating step of calculating a second voltage deviation between the first voltage deviation and a preset second criterion voltage in each cycle; and a discharge termination voltage adjusting step of adjusting the discharge termination voltage based on a criterion deviation set to correspond to a current cycle and the second voltage deviation calculated in the current cycle.

According to one aspect of the present disclosure, the battery management apparatus has an advantage of improving the performance efficiency of the battery and increasing the lifespan of the battery by adjusting the discharge termination voltage based on the voltage of the battery.

The scope of protection is defined solely by the appended claims.

<FIG> is a diagram schematically showing a battery management apparatus <NUM> according to the invention.

Referring to <FIG>, the battery management apparatus <NUM> includes a measuring unit <NUM> and a control unit <NUM>.

The measuring unit <NUM> is configured to measure the voltage of the battery after the discharge of the battery is terminated to a preset discharge termination voltage in every cycle.

Here, the battery means one physically separable independent cell including a negative electrode terminal and a positive electrode terminal. For example, one pouch-type lithium-ion battery may be regarded as a battery.

Here, the cycle may represent the number of times that the battery is completely discharged after being fully charged. For example, a process in which the battery is charged from <NUM>% to <NUM>% of SOC (State of Charge) and the battery is discharged from <NUM>% to <NUM>% of SOC may be expressed as one cycle.

Specifically, the measuring unit <NUM> may be configured to measure the rest voltage of the battery after a predetermined time elapses from the termination of discharge of the battery.

For example, the measuring unit <NUM> may measure the OCV (Open Circuit Voltage) of the battery after a predetermined time elapses from the termination of discharge of the battery.

In addition, the control unit <NUM> is configured to receive the voltage information of the battery from the measuring unit <NUM> in every cycle.

For example, the control unit <NUM> may be connected to communicate with the measuring unit <NUM>. Accordingly, the control unit <NUM> may receive voltage information of the battery from the measuring unit <NUM> in every cycle.

Specifically, the measuring unit <NUM> may be configured to transmit the voltage information of the battery to the control unit <NUM> in every cycle, so that the rest voltage is transmitted as the voltage information of the battery.

The control unit <NUM> is configured to calculate a first voltage deviation of the battery based on a preset first criterion voltage and the voltage of the battery.

Specifically, the control unit <NUM> may calculate the first voltage deviation by computing Formula <NUM> below.

Here, VD1 may be the first voltage deviation, V may be the voltage of the battery measured by the measuring unit <NUM>, and VR1 may be the first criterion voltage.

Specifically, the first criterion voltage is set for a battery in a BOL (Beginning of Life) state, and may be set as an open circuit voltage for the battery in a BOL state. Preferably, the first criterion voltage may be set as an open circuit voltage after the discharge to the battery in a BOL state is terminated. That is, the first voltage deviation VD1 may be calculated according to the difference between the preset first criterion voltage (open circuit voltage) and the measured voltage (open circuit voltage) of the battery.

<FIG> is a diagram schematically showing a voltage profile Pv of a battery according to an embodiment of the present disclosure and a voltage profile Rv of a reference cell. Specifically, the voltage profile Pv of the battery may be a profile representing a corresponding relationship between the cycle and the voltage of the battery.

For example, in the embodiment of <FIG>, in the <NUM>th cycle, the first voltage deviation VD1 may be preset to <NUM> mV. In the <NUM>th cycle, as a result of the calculation of "the voltage (V) of the battery - the first criterion voltage VR1" according to Formula <NUM>, the first voltage deviation VD1 may be calculated as -<NUM> mV. That is, in the <NUM>th cycle, the voltage (V) of the battery may be lower than the first criterion voltage VR1.

The control unit <NUM> is configured to calculate a second voltage deviation between the first voltage deviation and a preset second criterion voltage in each cycle.

Specifically, the control unit <NUM> may calculate the second voltage deviation by computing Formula <NUM> below.

Here, VD2 may be a second voltage deviation, VD1 may be the first voltage deviation according to Formula <NUM>, and VR2 may be the second criterion voltage. Specifically, the second criterion voltage VR2 may be the first voltage deviation VD1 in the <NUM>th cycle or a cycle immediately after the discharge termination voltage is changed.

For example, in the embodiment of <FIG>, the second criterion voltage VR2 of the <NUM>th to <NUM>th cycles may be <NUM> mV. That is, the criterion cycle in the <NUM>th to <NUM>th cycles may be the <NUM>th cycle, and the second criterion voltage VR2 may be <NUM> mV which is the first voltage deviation VD1 of the <NUM>th cycle. That is, in the <NUM>th cycle, the first voltage deviation VD1 and the second criterion voltage VR2 may be preset to <NUM> mV. In the <NUM>th to <NUM>th cycles, the control unit <NUM> may calculate the second voltage deviation VD2 by computing the difference between the first voltage deviation VD1 and the second criterion voltage VR2 of the battery according to Formula <NUM>.

Also, in the embodiment of <FIG>, the second criterion voltage VR2 of the <NUM>th cycle to the <NUM>th cycle may be <NUM> mV. That is, the criterion cycle in the <NUM>th cycle to the <NUM>th cycle may be the <NUM>th cycle, and the second criterion voltage VR2 may be <NUM> mV which is the first voltage deviation VD1 of the <NUM>th cycle. In the <NUM>th to <NUM>th cycles, the control unit <NUM> may calculate the second voltage deviation VD2 by computing the difference between the first voltage deviation VD1 and the second criterion voltage VR2 of the battery according to Formula <NUM>.

Also, in the embodiment of <FIG>, the criterion cycle after the <NUM>th cycle may be the <NUM>th cycle, and the second criterion voltage VR2 may be <NUM> mV, which is the first voltage deviation VD1 of the <NUM>th cycle. After the <NUM>th cycle, the control unit <NUM> may calculate the second voltage deviation VD2 by computing the difference between the first voltage deviation VD1 and the second criterion voltage VR2 of the battery according to Formula <NUM>.

The control unit <NUM> is configured to adjust the discharge termination voltage based on a criterion deviation set to correspond to the current cycle and the second voltage deviation calculated in the current cycle.

Specifically, the control unit <NUM> may be configured to determine a cycle region to which the current cycle belongs among a plurality of preset cycle regions.

For example, in the embodiment of <FIG>, the plurality of cycle regions may include a first cycle region R1 and a second cycle region R2. The first cycle region R1 may include <NUM>th to <NUM>th cycles, and the second cycle region R2 may include <NUM>st to <NUM>th cycles.

In addition, the control unit <NUM> may be configured to adjust the discharge termination voltage based on the criterion deviation set for the determined cycle region and the calculated second voltage deviation.

For example, the control unit <NUM> may be configured to increase the discharge termination voltage, when the calculated second voltage deviation is greater than or equal to the criterion deviation. Conversely, if the calculated second voltage deviation is less than the criterion deviation, the control unit <NUM> may maintain the discharge termination voltage as it is.

In the embodiment of <FIG>, the criterion deviation set for the first cycle region R1 may be <NUM> mV, and the criterion deviation set for the second cycle region R2 may be <NUM> mV. In addition, the second voltage deviation calculated in the <NUM>th cycle may be <NUM> mV. That is, in the <NUM>th cycle, since the second voltage deviation (<NUM> mv) between the second criterion voltage (<NUM> mV) and the first voltage deviation (-<NUM> mV) is greater than or equal to the criterion deviation (<NUM> mV) set for the first cycle region R1, the control unit <NUM> may increase the discharge termination voltage from the <NUM>th cycle.

In addition, the second criterion voltage may be changed from <NUM> mV to <NUM> mV from the <NUM>th cycle. That is, after the discharge termination voltage is changed, the control unit <NUM> may be configured to change the second criterion voltage to the first voltage deviation corresponding to a cycle after the discharge termination voltage is changed.

Also, the second voltage deviation calculated in the <NUM>th cycle may be <NUM> mV. That is, in the <NUM>th cycle, since the second voltage deviation (<NUM> mV) between the second criterion voltage (<NUM> mV) and the first voltage deviation (<NUM> mV) is greater than or equal to the criterion deviation (<NUM> mV) set for the second cycle region R2, the control unit <NUM> may further increase the discharge termination voltage from the <NUM>th cycle.

In addition, the second criterion voltage may be changed from <NUM> mV to <NUM> mV from the <NUM>th cycle. In the embodiment of <FIG>, since the second voltage deviation is not calculated as being equal to or greater than the criterion deviation after the <NUM>th cycle, the discharge termination voltage may not be further increased by the control unit <NUM>.

Referring to <FIG> further, the voltage profile Rv of the reference cell may be a voltage profile of the reference cell whose discharge termination voltage is not adjusted by the control unit <NUM>. Here, the reference cell corresponds to a battery, and may be a battery prepared for a comparative example that can be compared with the embodiment according to the present disclosure.

Since the discharge termination voltage is not adjusted for the reference cell, the first voltage deviation of the reference cell is decreased till about the <NUM>th cycle, and thereafter, the first voltage deviation may be increased.

A detailed comparison between the battery and the reference cell will be described with reference to <FIG> and <FIG>.

<FIG> is a diagram schematically showing a capacity profile Pcr of the battery according to an embodiment of the present disclosure and a capacity profile Rcr of the reference cell.

Specifically, the capacity profile of <FIG> may be a profile representing a corresponding relationship between a cycle and a capacity retention rate. Here, the capacity retention rate may be a ratio of the discharge capacity in the current cycle to the discharge capacity of the battery in the initial cycle.

In general, since battery cells are degraded as the cycle increases, the capacity retention rate may decrease as the cycle increases.

Referring to <FIG>, from the <NUM>th cycle to the <NUM>th cycle, the capacity retention rate of the battery and the reference cell may be equally reduced. On the other hand, from the <NUM>th cycle in which the discharge termination voltage for the battery is adjusted, the decrease rate of the capacity retention rate of the battery may be lower than the decrease rate of the capacity retention rate of the reference cell. In addition, from the <NUM>th cycle in which the discharge termination voltage for the battery is further adjusted, the decrease rate of the capacity retention rate of the battery may be lower than the decrease rate of the capacity retention rate of the reference cell.

That is, the battery management apparatus <NUM> according to an embodiment of the present disclosure may lower the decrease rate of the capacity retention rate of the battery by appropriately adjusting the discharge termination voltage for the battery. Therefore, as the battery and the reference cell are degraded, the battery may preserve more capacity compared to the reference cell, so the lifespan of the battery may be increased.

<FIG> is a diagram schematically showing a CE profile Pce of the battery according to an embodiment of the present disclosure and a CE profile Rce of the reference cell.

Specifically, the CE profile of <FIG> is a profile representing a corresponding relationship between a cycle and a coulombic efficiency (CE). Here, the coulombic efficiency means the ratio of the capacity in the current cycle to the capacity in the previous cycle.

Referring to <FIG>, the coulombic efficiency of the battery may be maintained within a predetermined level in the <NUM>th to about <NUM>th cycles. Referring to <FIG> further, since the discharge termination voltage is adjusted in the <NUM>th cycle and the <NUM>th cycle, the coulombic efficiency in the <NUM>th cycle and the <NUM>th cycle may be temporarily reduced, but the coulombic efficiency may be maintained within a certain level in the other cycles.

In addition, the coulombic efficiency of the battery is maintained within a predetermined level even after about the <NUM>th cycle, and may be increased after about the <NUM>th cycle.

On the other hand, the coulombic efficiency for the reference cell may decrease as the cycle increases, and may be increased after the <NUM>th cycle.

In other words, the coulombic efficiency of the battery whose discharge termination voltage is adjusted by the control unit is maintained within a certain range, but the coulombic efficiency of the reference cell for which the discharge termination voltage is not adjusted at all tends to decrease as the cycle increases (as the reference cell is degraded).

Therefore, the battery management apparatus <NUM> according to an embodiment of the present disclosure has an advantage of maintaining the coulombic efficiency of the battery at a certain level by adjusting the discharge termination voltage based on the voltage of the battery. Therefore, compared to the reference cell, the performance efficiency of the battery may be improved.

Meanwhile, the control unit <NUM> provided in the battery management apparatus <NUM> may selectively include processors known in the art, application-specific integrated circuit (ASIC), other chipsets, logic circuits, registers, communication modems, data processing devices, and the like to execute various control logic performed in the present disclosure. Also, when the control logic is implemented in software, the control unit <NUM> may be implemented as a set of program modules. At this time, the program module may be stored in a memory and executed by the control unit <NUM>. The memory may be located inside or out of the control unit <NUM> and may be connected to the control unit <NUM> by various well-known means.

In addition, the battery management apparatus <NUM> may further include a storage unit <NUM>. The storage unit <NUM> may store data necessary for operation and function of each component of the battery management apparatus <NUM>, data generated in the process of performing the operation or function, or the like. The storage unit <NUM> is not particularly limited in its kind as long as it is a known information storage means that can record, erase, update and read data. As an example, the information storage means may include RAM, flash memory, ROM, EEPROM, registers, and the like. In addition, the storage unit <NUM> may store program codes in which processes executable by the control unit <NUM> are defined.

For example, the voltage profile, the capacity profile, and the CE profile for the reference cell may be stored in advance in the storage unit <NUM>.

The plurality of cycle regions may be set based on the capacity retention rate of each cycle for the reference cell corresponding to the battery.

Preferably, the battery and the reference cell may include a negative electrode active material manufactured by mixing two or more materials. Specifically, the battery and the reference cell may include a negative electrode active material in which two or more materials having different charge/discharge efficiencies and reaction voltage ranges are mixed.

For example, in the embodiments of <FIG>, the battery and the reference cell may include a negative electrode active material in which SiO and graphite are mixed. In this case, SiO has lower charge/discharge efficiency and reaction voltage range than graphite, and may express a greater capacity in the initial cycle.

Accordingly, the plurality of cycle regions may be previously classified and set into a cycle region in which a greater capacity is expressed by SiO and a cycle region in which a greater capacity is expressed by graphite.

For example, in the embodiment of <FIG>, the plurality of cycle regions may be classified and set in advance into a first cycle region R1 including the <NUM>th to <NUM>th cycles corresponding to SiO and a second cycle region R2 after the <NUM>st cycle corresponding to graphite.

Therefore, the battery management apparatus <NUM> may adjust the discharge termination voltage to correspond to the degradation of the battery by setting a plurality of cycle regions in consideration of the composite negative electrode active material included in the battery and setting a criterion deviation for each cycle region. Therefore, the lifespan of the battery including the composite negative electrode active material may be increased.

Hereinafter, an embodiment in which a plurality of cycle regions are set by the control unit <NUM> will be described.

The control unit <NUM> may be configured to obtain a capacity profile representing a corresponding relationship between a cycle and a capacity for the reference cell corresponding to the battery.

For example, in the embodiment of <FIG>, the control unit <NUM> may obtain the capacity profile Rcr of the reference cell. The control unit <NUM> may obtain the capacity profile Rcr of the reference cell from an external server or an external device. Also, the control unit <NUM> may access the storage unit <NUM> to obtain the capacity profile Rcr of the reference cell previously stored in the storage unit <NUM>.

The control unit <NUM> may be configured to classify and set a plurality of cycles included in the capacity profile into a plurality of cycle regions according to the capacity change rate for the cycle.

For example, the capacity change rate may be an instantaneous change rate of the capacity retention rate for a cycle. That is, the control unit <NUM> may calculate the instantaneous change rate of the capacity retention rate for a cycle as the capacity change rate based on the obtained capacity profile Rcr of the reference cell.

The control unit <NUM> may be configured to compare the calculated capacity change rate with a criterion change rate and set a plurality of cycle regions according to the comparison result.

For example, the control unit <NUM> may compare the capacity change rate with the criterion change rate while increasing the cycle by <NUM> cycle from the <NUM>th cycle. In addition, the control unit <NUM> may determine a cycle in which the capacity change rate is equal to or less than the criterion change rate, and may classify a plurality of cycle regions based on the determined cycles. That is, the control unit <NUM> may be configured to classify a plurality of cycle regions based on a cycle in which degradation of the reference cell is accelerated.

In the embodiment of <FIG>, the capacity change rate in the <NUM>th cycle may be less than or equal to the criterion change rate. Accordingly, the control unit <NUM> may set previous cycles as the first cycle region R1 and set subsequent cycles as the second cycle region R2 based on the <NUM>th cycle.

Accordingly, the battery management apparatus <NUM> has an advantage of properly adjusting the discharge termination voltage of the battery by setting a plurality of cycle regions based on the capacity profile Rcr of the reference cell including a composite negative electrode active material in which two or more materials are mixed, and setting a criterion deviation corresponding to each of the plurality of cycles.

The control unit <NUM> may be configured to set a criterion deviation for each of the plurality of cycle regions, so that a criterion deviation corresponding to the first cycle region among the plurality of cycle regions is set to be lower than a criterion deviation corresponding to the remaining cycle regions.

For example, in the embodiments of <FIG>, the criterion deviation set in the first cycle region R1 may be set smaller than the criterion deviation set in the second cycle region R2.

Specifically, in a battery including two or more types of composite negative electrode active materials, since a capacity is expressed such that the use area of the active material with low charge/discharge efficiency and reaction voltage range is expanded in the initial cycle, the decrease amount of the capacity change rate in the initial cycle may be small.

However, as the capacity of an active material with low charge/discharge efficiency and reaction voltage range is expressed, even though it seems that the total capacity of the battery is preserved, the degradation of the battery may be accelerated.

For example, referring to the capacity profile Rcr of the reference cell of <FIG>, the change rate of the capacity retention rate in the first cycle region R1 may be lower than the change rate of the capacity retention rate in the second cycle region R2 due to the capacity expression of SiO. However, since the reference cell is degraded due to the capacity expression of SiO, the control unit <NUM> may set the criterion deviation for the first cycle region R1 to be lower than the criterion deviation for the second cycle region R2. In addition, the control unit <NUM> may further suppress the capacity expression of SiO included in the battery by adjusting the discharge termination voltage of the battery based on the criterion deviation set differently in the first cycle region R1 and the second cycle region R2. Therefore, since the capacity expression of SiO in the battery may be effectively reduced in the initial cycle, the lifespan of the battery may be increased and the performance efficiency may be improved.

The battery management apparatus <NUM> according to the present disclosure may be applied to a BMS (Battery Management System). That is, the BMS according to the present disclosure may include the battery management apparatus <NUM> described above. In this configuration, at least some of the components of the battery management apparatus <NUM> may be implemented by supplementing or adding functions of the configuration included in the conventional BMS. For example, the measuring unit <NUM>, the control unit <NUM> and the storage unit <NUM> may be implemented as components of the BMS.

<FIG> is a diagram schematically showing an exemplary configuration of a battery pack <NUM> according to another embodiment of the present disclosure.

The battery management apparatus <NUM> according to the present disclosure is provided in a battery pack <NUM>. That is, the battery pack <NUM> according to the present disclosure includes the above-described battery management apparatus <NUM> and one or more battery cells B. In addition, the battery pack <NUM> may further include electrical equipment (relays, fuses, etc.) and a case.

Referring to <FIG>, a load <NUM> may be connected to a battery B through a positive electrode terminal P+ and a negative electrode terminal P- of the battery pack <NUM>. The load <NUM> may be configured to charge and discharge the battery B. Preferably, the load <NUM> may discharge the battery B to a discharge termination voltage. In addition, the load <NUM> may discharge the battery B to correspond to the discharge termination voltage changed by the control unit <NUM>.

The measuring unit <NUM> may be connected to the battery B through a first sensing line SL1 and a second sensing line SL2. The measuring unit <NUM> may measure the positive electrode voltage of the battery B through the first sensing line SL1 and measure the negative electrode voltage of the battery B through the second sensing line SL2. In addition, the measuring unit <NUM> may measure the voltage of the battery B by calculating the difference between the measured positive electrode voltage and the measured negative electrode voltage.

If the reference cell RB is included in the battery pack <NUM>, the measuring unit <NUM> measures the voltage of the reference cell RB, but the discharge termination voltage for the reference cell RB may not be adjusted by the control unit <NUM>.

<FIG> is a diagram schematically showing a battery management method according to the invention.

Preferably, each step of the battery management method may be performed by the battery management apparatus <NUM>. Hereinafter, it should be noted that contents overlapping with the previously described contents will be omitted or briefly described.

Referring to <FIG>, the battery management method includes a voltage measuring step (S100), a first voltage deviation calculating step (S200), a second voltage deviation calculating step (S300), and a discharge termination voltage adjusting step (S400).

The voltage measuring step (S100) is a step of measuring the voltage of the battery B after the discharge of the battery B is terminated to a preset discharge termination voltage in every cycle, and may be performed by the measuring unit <NUM>.

The first voltage deviation calculating step (S200) is a step of calculating the first voltage deviation of the battery B based on a preset first criterion voltage and the voltage of the battery B, and may be performed by the control unit <NUM>.

For example, the control unit <NUM> may calculate the first voltage deviation for the battery B in every cycle based on the measured voltage of the battery B and the preset first criterion voltage.

The second voltage deviation calculating step (S300) is a step of calculating a second voltage deviation between the first voltage deviation and a preset second criterion voltage in each cycle, and may be performed by the control unit <NUM>.

For example, in the <NUM>th to <NUM>th cycles of the embodiment of <FIG>, the control unit <NUM> may calculate the second voltage deviation VD2 by computing the difference between the first voltage deviation VD1 and the second criterion voltage VR2 of the battery according to Formula <NUM>. The second criterion voltage VR2 of the <NUM>th to <NUM>th cycles may be <NUM> mV, which is the first voltage deviation VD1 of the <NUM>th cycle.

In addition, in the <NUM>th to <NUM>th cycles of the embodiment of <FIG>, the control unit <NUM> may calculate the second voltage deviation VD2 by computing the difference between the first voltage deviation VD1 and the second criterion voltage VR2 of the battery according to Formula <NUM>. The second criterion voltage VR2 of the <NUM>th to <NUM>th cycles may be <NUM> mV, which is the first voltage deviation VD1 of the <NUM>th cycle.

In addition, the criterion cycle after the <NUM>th cycle of the embodiment of <FIG> may be the <NUM>th cycle, and the second criterion voltage VR2 may be <NUM> mV, which is the first voltage deviation VD1 of the <NUM>th cycle.

The discharge termination voltage adjusting step (S400) is a step of adjusting the discharge termination voltage based on a criterion deviation set to correspond to the current cycle and a second voltage deviation calculated from the current cycle, and may be performed by the control unit <NUM>.

In addition, the second voltage deviation calculated in the <NUM>th cycle may be <NUM> mV. That is, in the <NUM>th cycle, since the second voltage deviation (<NUM> mV) between the second criterion voltage (<NUM> mV) and the first voltage deviation (<NUM> mV) is greater than or equal to the criterion deviation (<NUM> mV) set for the second cycle region R2, the control unit <NUM> may further increase the discharge termination voltage from the <NUM>th cycle.

Claim 1:
A battery management apparatus (<NUM>), comprising:
a measuring unit (<NUM>) configured to measure a voltage of a battery after discharge of the battery is terminated to a preset discharge termination voltage in every cycle; and
a control unit (<NUM>) configured to receive voltage information of the battery from the measuring unit in every cycle, calculate a first voltage deviation of the battery based on a preset first criterion voltage and the voltage of the battery, calculate a second voltage deviation between the first voltage deviation and a preset second criterion voltage in each cycle, and adjust the discharge termination voltage based on a criterion deviation set to correspond to a current cycle and the second voltage deviation calculated in the current cycle.