Battery capacity estimating system and method

Claim 2

A remaining capacity measuring system for a rechargeable storage battery of an automobile, comprising: first switching means responsive to a command signal from an electronic control unit for setting said battery in a disconnected state to all of electrical loads of said automobile except said electronic control unit; second switching means responsive to another command signal from said electronic control unit for setting said battery in a selectively connected state to an electrical load excluding said electronic control unit; first voltage detecting means for detecting a first voltage between a positive and negative terminal of said battery in said disconnected state; second voltage detecting means for detecting a second voltage between a positive and negative terminal of said battery in said selectively connected state; discharge current detecting means for detecting a discharge current flowing between said battery and said electrical load in said selectively connected state; temperature sensing means for sensing an electrolyte temperature of said battery; input signal converting means for converting analogue signals of said first voltage signal, said second voltage signal, said discharge current signal and said electrolyte temperature signal, into digital signals and for outputting said digital signals to a CPU of said electronic control unit; internal resistance calculating means for calculating an internal resistance value of said battery based on said first voltage signal from said input signal converting means, said second voltage signal from said input signal converting means and said discharge current signal from said input signal converting means and for outputting said internal resistance value; capacity data memory means for storing a remaining capacity level of said battery on a first map parameterizing an internal resistance value and a discharge current value; capacity estimating means for reading said remaining capacity level corresponding to said internal resistance value and said discharge current value on said first map and for outputting said remaining capacity level; correction coefficients memory means for storing a temperature correction coefficient on a second map parameterizing an electrolyte temperature; capacity correcting mean for reading said temperature correction coefficient corresponding to said electrolyte temperature from said second map, for correcting said remaining capacity level outputted from said capacity estimating means by said temperature correction coefficient, and for outputting a corrected remaining capacity level; and display means for displaying said corrected remaining capacity level outputted from said temperature correcting means.

Claim 3

The remaining capacity measuring system according to claim 1, wherein said internal resistance value is obtained by means of dividing a difference between said first voltage value and said second voltage value by said discharge current value.

Claim 4

A remaining capacity measuring system for a rechargeable chargeable storage battery of an automobile, comprising: first switching means responsive to a command signal from an electronic control unit for setting said battery in a disconnected state to all of electrical loads of said automobile except said electronic control unit; second switching means responsive to another command signal from said electronic control unit for setting said battery in a selectively connected state to a reference resistance whose resistance value is known; first voltage detecting means for detecting a first voltage value between a positive and negative terminal of said battery in said disconnected state; second voltage detecting means for detecting a second voltage value between a positive and negative terminal of said battery in said selectively connected state; temperature sensing means for sensing an electrolyte temperature of said battery; input signal converting means for converting analogue signals of said first voltage value signal, said second voltage value signal, and said electrolyte temperature signal, into digital signals and for outputting said digital signals to a CPU of said electronic control unit; discharge current calculating means responsive to said second voltage value signal from said input signal converting means for calculating a discharge current value based on a resistance value of said reference resistance and for outputting said discharge current; internal resistance calculating means for calculating an internal resistance value of said battery based on said first voltage value from said input signal converting means, said second voltage value signal from said input signal converting means and said discharge current value signal from said discharge current calculating means and for outputting said internal resistance value signal; capacity data memory means for storing a remaining capacity level of said battery on a first map parameterizing an internal resistance value and an discharge current value; capacity estimating means for reading said remaining capacity level corresponding to said internal resistance value and said discharge current value on said first map and for outputting said remaining capacity level; correction coefficients memory means for storing a temperature correction coefficient on a second map parameterizing an electrolyte temperature; capacity correcting means for reading said temperature correction coefficient corresponding to said electrolyte temperature from said second map, for correcting said remaining capacity level outputted from said capacity estimating means by said temperature correction coefficient, and for outputting a corrected remaining capacity level; and display means for displaying said corrected remaining capacity level outputted from said temperature correcting means.

Claim 5

A remaining capacity measuring system for a rechargeable chargeable storage battery of an automobile, comprising: first switching means responsive to a command signal from an electronic control unit for setting said battery in a disconnected state to all of electrical loads of said automobile except said electronic control unit; second switching means responsive to another command signal from said electronic control unit for setting said battery in a selectively connected state to a reference resistance whose resistance value is known; first voltage detecting means for detecting a first voltage value between a positive and negative terminal of said battery in said disconnected state; second voltage detecting means for detecting a second voltage value between a positive and negative terminal of said battery in said selectively connected state; temperature sensing means for sensing an electrolyte temperature of said battery; input signal converting means for converting analogue signals of said first voltage value signal, said second voltage value signal, and said electrolyte temperature signal, into digital signals and for outputting said digital signals to a CPU of said electronic control unit; discharge current calculating means responsive to said second voltage value signal from said input signal converting means for calculating a discharge current value based on a resistance value of said reference resistance and for outputting said discharge current; internal resistance calculating means for calculating an internal resistance value of said battery based on said first voltage value from said input signal converting means, said second voltage value signal from said input signal converting means and said discharge current value signal from said discharge current calculating means and for outputting said internal resistance value signal; capacity data memory means for storing a remaining capacity level of said battery on a first map parameterizing an internal resistance value and an discharge current value; capacity estimating means for reading said remaining capacity level corresponding to said internal resistance value and said discharge current value on said first map and for outputting said remaining capacity level; correction coefficients memory means for storing a temperature correction coefficient on a second map parameterizing an electrolyte temperature; capacity correcting means for reading said temperature correction coefficient corresponding to said electrolyte temperature from said second map, for correcting said remaining capacity level outputted from said capacity estimating means by said temperature correction coefficient, and for outputting a corrected remaining capacity level; and display means for displaying said corrected remaining capacity level outputted from said temperature correcting means.

Claim 6

The remaining capacity measuring system according to claim 3, wherein said discharge current is obtained by means of dividing said second voltage by said resistance value of said reference resistance.

Claim 7

The remaining capacity measuring system according to claim 3, wherein said internal resistance value is obtained by means of dividing a difference between said first voltage value and said second voltage value by said discharge current value.

Claim 8

The remaining capacity measuring system according to claim 3, wherein said reference resistance is replaced with at least one electrical equipment of said automobile whose resistance value is known.

Claim 11

The method according to claim 7, wherein said internal resistance value is obtained by means of dividing a difference between said first voltage value and said second voltage value by said discharge current value.

Claim 14

The method according to claim 9, wherein said discharge current is obtained by means of dividing said second voltage by said resistance value of said reference resistance.

Claim 15

The method according to claim 9, wherein said internal resistance value is obtained by means of dividing a difference between said first voltage value and said second voltage value by said discharge current value.

Claim 16

The method according to claim 9, wherein said reference resistance is replaced with at least one electrical equipment of said automobile whose resistance value is known.