Method and apparatus for testing a battery

Claim 3

The method of Claim 1 wherein said step of determining the operating condition and/or characteristics of said battery comprises comparing the obtained voltage-current characteristic to a predetermined voltage-current characteristic representing batteries of the type being tested and known to be in desirable operating condition; and determining the operating condition and/or characteristics of said battery as a function of said comparison.

Claim 4

The method of Claim 2 wherein said step of obtaining the dynamic voltage-current characteristic includes obtaining the open-circuit voltage produced across said pair of output terminals of said battery in response to substantially zero charging current; and said predetermined voltage-current characteristic is the voltage-current characteristic having an open-circuit voltage substantially equal to the open-circuit voltage obtained for the battery under test.

Claim 5

The method of claim 1 further comprising the steps of determining the slope of said dynamic voltage-current characteristic, thereby representing the charge capacity of the battery under test; obtaining the open-circuit voltage produced across said output terminals of said battery in response to substantially zero charging current; comparing the obtained open-circuit voltage to reference open-circuit voltage levels associated with batteries having substantially the same charge capacity as that determined for said battery under test; and determining the charge condition of said battery under test as a function of said comparison.

Claim 6

The method of claim 4, further comprising the steps of sensing predetermined changes in the slope of said obtained voltage-current characteristic; and determining that said battery under test is charged to its gassing condition when said predetermined changes in said slope are sensed at a preselected charge condition for said determined-charge capacity of said battery under test.

Claim 7

The method of claim 5, further comprising the step of determining a fault condition in said battery under test if said predetermined changes in said slope are sensed at less than said preselected charge condition.

Claim 8

. The method of claim 1 wherein said step of supplying a controllably varying charging current comprises generating an increasing ramp current followed by a decreasing ramp current; and supplying said ramp currents to said battery.

Claim 11

The method of claim 8, further comprising the step of storing digital data representing operating conditions and/or characteristics correlated with said predetermined standard voltages; and wherein said step of comparing the measured voltage to said predetermined standard voltages comprises converting said measured voltage to corresponding digital representations thereof, and comparing said converted digital representations to said stored data to determine the operating condition and/or characteristics of said battery under test.

Claim 14

Apparatus for testing a battery comprising energizing means (18) coupled to said battery (10) to supply energy thereto; sensing means (26; 34) coupled to said battery to sense voltage'thereacross and current thereto; and control means (12, 14; 30) coupled to said energizing means and to said sensing means for controlling the energy supplied to said battery by said energizing means and responsive to at least one of the sensed voltage and current to obtain the dynamic voltage-current characteristic of said battery and to determine the charge condition of said battery as a function of said dynamic voltage-current characteristic.

Claim 15

Apparatus for testing a battery comprising energizing means (18) coupled to said battery (10) to supply energy thereto; sensing means (26; 34) coupled to said battery to sense voltage'thereacross and current thereto; and control means (12, 14; 30) coupled to said energizing means and to said sensing means for controlling the energy supplied to said battery by said energizing means and responsive to at least one of the sensed voltage and current to obtain the dynamic voltage-current characteristic of said battery and to determine the charge condition of said battery as a function of said dynamic voltage-current characteristic.

Claim 16

The apparatus of claim 11, wherein said energizing means (18) comprises means for supplying current to said battery, and said control means (12, 13, 30) controls said energizing means to supply a controllably varying charging current to said battery.

Claim 17

The apparatus of claim 12, wherein said control means is responsive to said sensed voltage to obtain said dynamic voltage-current characteristic of said battery as a function of said sensed voltage and said supplied charging current.

Claim 18

The apparatus of claim 13, wherein said means for supplying current to said battery comprises current ramp generating means, responsive to said control means, for generating a current ramp which increases with respect to time followed by a current ramp which decreases with respect to time.

Claim 19

Apparatus for testing a battery comprising energizing means (18) coupled to said battery (10) to selectively supply current and voltage thereto; sensing means (34) coupled to said battery to sense voltage thereacross; and data processing means (30) programmed to control said energizing means and to determine the charge condition of said battery as a function of the sensed voltage.

Claim 20

Apparatus for testing a battery comprising energizing means (18) coupled to said battery (10) to selectively supply current and voltage thereto; sensing means (34) coupled to said battery to sense voltage thereacross; and data processing means (30) programmed to control said energizing means and to determine the charge condition of said battery as a function of the sensed voltage.

Claim 21

The apparatus of claim 15, wherein said data processing means is programmed to control said energizing means to supply a gradually increasing current followed by a gradually decreasing current to said battery.

Claim 22

The apparatus of claim 16, wherein said data processing means is programmed to derive a dynamic voltage-current characteristic as a function of the voltage sensed across said battery and the current supplied to said battery.

Claim 23

The apparatus of claim 17, wherein said data processing means is programmed to determine the slope of said derived dynamic voltage-current characteristic.

Claim 24

The apparatus of claim 18, wherein said data processing means includes memory means (36) for storing data representing battery charge capacities correlated with different dynamic voltage-current characteristic slopes; and said data processing means is programmed to compare said determined slope with said stored data to obtain an indication of the charge capacity of said battery.

Claim 25

Apparatus for testing a battery comprising energizing means (18) coupled to said battery (10) to selectively supply current and voltage thereto; sensing means (34) coupled to said battery to sense voltage thereacross; and data processing means (30) including memory means for storing charge capacity data representing dharge capacities of different batteries, gas voltage data representing the gas voltage levels of said batteries, charge level data representing the charge levels of said batteries as a function of the battery voltage thereof, and fault data representing predetermined battery fault conditions as a function of battery voltage; said data processing means being programmed to control said energizing means to supply a test current having gradually increasing and decreasing portions and to obtain a dynamic voltage-current characteristic as a function of said supplied current and the voltage across said battery sensed by said sensing means while said current is supplied; said data processing means being further programmed to determine the number of cells included in said battery as a function of said sensed voltage when said current is substantially zero; said data processing means being further programmed to determine the slope of said dynamic voltage-current characteristic and to derive the charge capacity of said battery as a function of the determined number of cells and determined slope; said data processing means being further programmed to compare said sensed voltage when said current is substantially zero to said stored charge level data to derive the charge level of said battery; and said data processing means being further programmed to compare said obtained dynamic voltage-current characteristic to said fault data to indicate the presence of a battery fault condition.

Claim 26

Apparatus for testing a battery comprising energizing means (18) coupled to said battery (10) to selectively supply current and voltage thereto; sensing means (34) coupled to said battery to sense voltage thereacross; and data processing means (30) including memory means for storing charge capacity data representing dharge capacities of different batteries, gas voltage data representing the gas voltage levels of said batteries, charge level data representing the charge levels of said batteries as a function of the battery voltage thereof, and fault data representing predetermined battery fault conditions as a function of battery voltage; said data processing means being programmed to control said energizing means to supply a test current having gradually increasing and decreasing portions and to obtain a dynamic voltage-current characteristic as a function of said supplied current and the voltage across said battery sensed by said sensing means while said current is supplied; said data processing means being further programmed to determine the number of cells included in said battery as a function of said sensed voltage when said current is substantially zero; said data processing means being further programmed to determine the slope of said dynamic voltage-current characteristic and to derive the charge capacity of said battery as a function of the determined number of cells and determined slope; said data processing means being further programmed to compare said sensed voltage when said current is substantially zero to said stored charge level data to derive the charge level of said battery; and said data processing means being further programmed to compare said obtained dynamic voltage-current characteristic to said fault data to indicate the presence of a battery fault condition.