Battery control apparatus

1 . A battery control apparatus comprising:

a battery module comprising a plurality of batteries, and

a battery controller, the battery controller including:

a memory; and

a control circuit that executes a program recorded in the memory and controls actions of each of the batteries of the battery module,

wherein the memory stores battery data including a relation between a DC resistance component and a state of charge and a relation between a polarization resistance component and the state of charge; and

wherein the control circuit:

estimates a state of health of each of the batteries based on a calculated battery capacity reduction rate, wherein the control circuit is configured to update the estimated state of health of each of the batteries each time the batteries are charged or a device powered by the batteries is powered on,

determines allowable currents for each of the batteries by referring to the battery data and extracting the relation between the DC resistance component and the state of charge and the relation between the polarization resistance component and the state of charge on the basis of the estimated state of health of the battery at present,

sets the allowable current for each of the batteries to be a current whose absolute value is a minimum of the determined allowable currents, and

charges or discharges each of the batteries based on the set allowable current.

2 . The battery control apparatus according to claim 1 , comprising:

a current sensor that measures an electric current (I) of the battery module;

a voltage sensor that measures a voltage (V) of the battery module; and

a temperature sensor that measures a temperature (T) of each of the batteries of the battery module,

wherein the control circuit calculates a capacity decrease rate of each of the batteries on the basis of the electric current (I), the voltage (V), and the temperature (T) and estimates the state of health of the battery.

3 . The battery control apparatus according to claim 2 ,

wherein the control circuit estimates the state of charge of the battery on the basis of the electric current (I), the voltage (V), the temperature (T), and an equivalent circuit model of the battery.

4 . The battery control apparatus according to claim 3 ,

wherein the memory includes a battery data table as the battery data; and

wherein items of the battery data table include the battery capacity reduction rate (SOH), a battery temperature (T), a battery charging rate (SOC), a battery current (I), battery DC resistance (Ro), battery polarization resistance (Rp), and a battery polarization capacity (Cp).

5 . The battery control apparatus according to claim 4 ,

wherein respective values of each of the batteries DC resistance Ro (Ω), the polarization resistance Rp (Ω), and the polarization capacity Cp (F) are set to the battery data table with respect to each of a plurality of combinations in which the battery capacity reduction rate (SOH), the battery temperature (T), the battery charging rate (SOC), and the battery current (I) are respectively specified values.

6 . The battery control apparatus according to claim 5 ,

wherein the control circuit arithmetically operates the allowable current of each of the batteries on the basis of the battery capacity reduction rate (SOH), the battery temperature (T), and the battery charging rate (SOC) at present by referring to the battery DC resistance (Ro), the battery polarization resistance (Rp), and the battery polarization capacity (Cp) which are stored in the battery data table.

7 . The battery control apparatus according to claim 6 ,

wherein the batteries are connected in series.

8 . The battery control apparatus according to claim 6 ,

wherein the battery module has a configuration such that a plurality of groups, in each of which a plurality of battery cells are connected in series, are connected in parallel; and

wherein the control circuit sets allowable currents to the plurality of groups, respectively, and sets a total sum of the allowable currents of the respective groups as an allowable current of the battery module.