Accurate battery state-of-charge monitoring and indicating apparatus and method

Claim 2

For an electrical load circuit driven by an operatively connected battery, wherein such battery has an experimentally defined charge capacity (CCAP) substantially based on a predefined discharging current (I) during a depletion test of the battery, a method of monitoring an accurate state-of-charge of a battery comprising; storing CCAP as state-of-charge (SOC) of the battery in an associated memory; measuring a discharging current (i) drawn from the battery; determining if i is less than or approximately equal to I; if so, then setting an effective discharging current (i eff ) equal to i; otherwise setting i eff equal to K·i P , wherein K and P are Peukert constants being experimentally defined by changes of CCAP of the battery in depletion tests in relation to changes of i to satisfy Peukert Equation; and decrementing SOC based on i eff while discharging the battery.

Claim 3

The method of claim 1 further comprising repeating said measuring, said determining and said decrementing steps until the battery is substantially depleted.

Claim 4

The method of claim 1 further comprising indicating an accurate state-of-charge of the battery based on SOC in said decrementing step.

Claim 5

The method of claim 1 further comprising estimating time remaining until the battery is substantially depleted based on SOC in said decrementing step and based on i eff , and indicating the time remaining.

Claim 7

A method as in one of claim 1-4, in which a temperature sensor is located adjacent the battery, further comprising: providing and storing in an associated memory a nominal operating temperature (OPTEMP) of the battery; measuring ambient temperature adjacent the battery with the sensor; and compensating for an ambient temperature which deviates from OPTEMP.

Claim 9

For an electrical load circuit driven by an operatively connected battery, wherein such battery has an experimentally defined charge capacity (CCAP) which is substantially based upon a depletion test, wherein such battery in a fully-charged condition is depleted over a depletion time period (T) while drawing a predefined discharging current (I)from such battery, a method of monitoring an accurate state-of-charge of a battery comprising: storing CCAP as state-of-charge (SOC) of the battery in an associated memory; generating a value of an adjusted charge capacity (CCAP adj ) substantially based upon an equation CCAP adj =T·I P , wherein P is a Peukert constant which is experimentally defined by an equation P=(log T 2 -log T 1 )÷(log I, -log I 2 ), wherein T 1 and I 1 are a period of time and discharging current respectively of a nominally first depletion test of the battery and T 2 and I 2 are a period of time and discharging current respectively of a nominally second depletion test of the battery such that I 1 is greater than I 2 ; storing value of CCAP adj as an adjusted state-of-charge (SOC adj in a memory associated with SOC adj ; measuring a discharging current (i) drawn from the battery determining if i is less than or approximately equal to I; if so, then setting an adjusted discharging current (i adj ) equal to i·I.sup.(P-1) ; otherwise, setting i adj equal to i P ; and decrementing SOC adj based on i adj while discharging the battery.

Claim 10

For an electrical load circuit driven by an operatively connected battery, wherein such battery has an experimentally defined charge capacity (CCAP) which is substantially based upon a depletion test, wherein such battery in a fully-charged condition is depleted over a depletion time period (T) while drawing a predefined discharging current (I)from such battery, a method of monitoring an accurate state-of-charge of a battery comprising: storing CCAP as state-of-charge (SOC) of the battery in an associated memory; generating a value of an adjusted charge capacity (CCAP adj ) substantially based upon an equation CCAP adj =T·I P , wherein P is a Peukert constant which is experimentally defined by an equation P=(log T 2 -log T 1 )÷(log I, -log I 2 ), wherein T 1 and I 1 are a period of time and discharging current respectively of a nominally first depletion test of the battery and T 2 and I 2 are a period of time and discharging current respectively of a nominally second depletion test of the battery such that I 1 is greater than I 2 ; storing value of CCAP adj as an adjusted state-of-charge (SOC adj in a memory associated with SOC adj ; measuring a discharging current (i) drawn from the battery determining if i is less than or approximately equal to I; if so, then setting an adjusted discharging current (i adj ) equal to i·I.sup.(P-1) ; otherwise, setting i adj equal to i P ; and decrementing SOC adj based on i adj while discharging the battery.

Claim 11

The method of claim 8 further comprising repeating said measuring, said determining and said decrementing steps until the battery is substantially depleted.

Claim 12

The method of claim 8 further comprising indicating an accurate state-of-charge of the battery substantially based on SOC adj .

Claim 13

The method of claim 8 further comprising estimating time remaining until the battery is substantially depleted based on SOC adj and on i adj , and indicating the time remaining.

Claim 18

For a battery with a battery charger operatively connected thereto, wherein such battery has an experimentally defined charge capacity (CCAP) which is substantially based upon a depletion test, wherein such battery in a fully-charged condition is depleted over a depletion time period (T) while drawing a predefined discharging current (1) from such battery; a method of monitoring an accurate state-of-charge of a battery comprising: providing a less-than-fully-charged battery, wherein the battery has: a) an adjusted charge capacity (CCAP adj ) which is satisfied by an equation CCAP adj =T·I P , wherein P is a Peukert constant which is experimentally defined by an equation P=(log T 2 -log T 1 )÷(log I 1 -log I 2 ), wherein T 1 and I 1 are a period of time and discharging current respectively of a nominally first depletion test of the battery and T 2 and I 2 are a period of time and discharging current respectively of a nominally second depletion test of the battery such that I 1 is greater than I 2 , which CCAP adj is stored in an associated memory; b) a state-of-charge (SOC) which is stored in an associated memory; and c) an adjusted state-of-charge SOC adj stored in an associated memory, wherein SOC adj is equal to SOC which has been adjusted to compensate for the Peukert Effect during discharging of the battery; charging the less-than-fully-charged battery with the battery charger by causing a charging current (z) to flow through the battery; measuring z and setting an adjusted charging current (z adj ) equal to z; producing a charging compensation factor (COMF) wherein COMF is defined by an equation COMF=SOC adj ÷SOC; modifying z adj so that z adj =z adj ·COMF·CEF, wherein CEF is a defined charging efficiency factor of the battery; incrementing SOC adj based on z adj while charging the battery.

Claim 19

For a battery with a battery charger operatively connected thereto, wherein such battery has an experimentally defined charge capacity (CCAP) which is substantially based upon a depletion test, wherein such battery in a fully-charged condition is depleted over a depletion time period (T) while drawing a predefined discharging current (1) from such battery; a method of monitoring an accurate state-of-charge of a battery comprising: providing a less-than-fully-charged battery, wherein the battery has: a) an adjusted charge capacity (CCAP adj ) which is satisfied by an equation CCAP adj =T·I P , wherein P is a Peukert constant which is experimentally defined by an equation P=(log T 2 -log T 1 )÷(log I 1 -log I 2 ), wherein T 1 and I 1 are a period of time and discharging current respectively of a nominally first depletion test of the battery and T 2 and I 2 are a period of time and discharging current respectively of a nominally second depletion test of the battery such that I 1 is greater than I 2 , which CCAP adj is stored in an associated memory; b) a state-of-charge (SOC) which is stored in an associated memory; and c) an adjusted state-of-charge SOC adj stored in an associated memory, wherein SOC adj is equal to SOC which has been adjusted to compensate for the Peukert Effect during discharging of the battery; charging the less-than-fully-charged battery with the battery charger by causing a charging current (z) to flow through the battery; measuring z and setting an adjusted charging current (z adj ) equal to z; producing a charging compensation factor (COMF) wherein COMF is defined by an equation COMF=SOC adj ÷SOC; modifying z adj so that z adj =z adj ·COMF·CEF, wherein CEF is a defined charging efficiency factor of the battery; incrementing SOC adj based on z adj while charging the battery.

Claim 20

the method of claim 16 further comprising repeating said charging, said measuring, said producing, said modifying and said incrementing steps until SOC adj is substantially equal to CCAP adj .

Claim 21

The method of claim 16 further comprising indicating the state-of-charge of the battery based on SOC adj .

Claim 22

The method of claim 16 further comprising estimating time remaining until the battery is substantially fully charged based on SOC adj and on Z adj , and indicating the time remaining.

Claim 25

An accurate battery state-of-charge monitor for an electrical load circuit driven by an operatively connected battery, wherein such battery has an experimentally defined charge capacity (CCAP) which is substantially based upon a depletion test of the battery at a predefined discharging current (I), the monitor comprising: a state-of-charge memory for storing state-of-charge (SOC) of the battery therein, wherein when the battery is in a fully-charged condition, the value of CCAP is stored in the state-of-charge memory; a baseline-current memory for storing the value of I therein; an effective-discharging-current memory for storing an effective discharging current (i eff ); a current meter operatively connected to the load circuit for measuring a discharging current (i) drawn from the battery; and a processor operatively connected to each of said memories and to said current meter, wherein the processor determines if i is less than or approximately equal to stored I; if so, then the value of i is stored as i eff in the effective-discharging-current memory; otherwise, the value of K·i P is stored as i eff in the effective-discharging-current memory, wherein K and P are Peukert constants being experimentally defined by changes of charge capacity of the battery in depletion tests in relation to changes of i to satisfy Peukert Equation, and the processor decrements stored SOC based on stored i eff while battery is being discharged.

Claim 26

An accurate battery state-of-charge monitor for an electrical load circuit driven by an operatively connected battery, wherein such battery has an experimentally defined charge capacity (CCAP) which is substantially based upon a depletion test of the battery at a predefined discharging current (I), the monitor comprising: a state-of-charge memory for storing state-of-charge (SOC) of the battery therein, wherein when the battery is in a fully-charged condition, the value of CCAP is stored in the state-of-charge memory; a baseline-current memory for storing the value of I therein; an effective-discharging-current memory for storing an effective discharging current (i eff ); a current meter operatively connected to the load circuit for measuring a discharging current (i) drawn from the battery; and a processor operatively connected to each of said memories and to said current meter, wherein the processor determines if i is less than or approximately equal to stored I; if so, then the value of i is stored as i eff in the effective-discharging-current memory; otherwise, the value of K·i P is stored as i eff in the effective-discharging-current memory, wherein K and P are Peukert constants being experimentally defined by changes of charge capacity of the battery in depletion tests in relation to changes of i to satisfy Peukert Equation, and the processor decrements stored SOC based on stored i eff while battery is being discharged.

Claim 27

The monitor of claim 22 further comprising a state-of-charge indicator for indicating the accurate state-of-charge of the battery based on SOC, the state-of-charge indicator being operatively connected to the processor.

Claim 28

The monitor of claim 22 further comprising a time-remaining indicator for indicating time remaining until the battery is substantially depleted, wherein the processor calculates the time remaining based on SOC and on stored i eff , and wherein the processor is operatively connected to the time-remaining indicator.

Claim 29

A monitor as in one of claims 22-24 further comprising an average-discharging-current memory for storing an average of i, wherein the processor averages i over a defined current-averaging period of time, sets i equal to the average discharging current and stores the average discharging current in the average-discharging-current memory.

Claim 30

A monitor as in one of claims 22-24, in which a temperature sensor is located adjacent the battery and is operatively connected to the processor, the sensor for measuring the ambient temperature adjacent the battery, further comprising a nominal-operating-temperature memory operatively connected to the processor, the nominal-operating-temperature memory for storing therein a predefined nominal operating temperature (OPTEMP) of the battery, wherein if a measured ambient temperature adjacent the battery deviates from stored OPTEMP, the processor modifies stored values to compensate for such temperature deviation.

Claim 31

An accurate battery state-of-charge monitor for an electrical load circuit driven by an operatively connected battery, wherein such battery has an experimentally defined charge capacity (CCAP) which is substantially based upon a depletion test, wherein such battery in a fully-charged condition is depleted over a depletion time period (T) while drawing a predefined discharging current (I) from such battery, the monitor comprising: a state-of-charge memory for storing state-of-charge (SOC) of the battery, wherein when the battery is in a fully-charged condition, the value of CCAP is stored in the state-of-charge memory; a baseline-current memory for storing the value of I therein; an adjusted-charge-capacity memory for storing an adjusted charge capacity (CCAP adj ) of the battery, wherein CCAP adj is defined by an equation CCAP adj =T·I P , wherein P is a Peukert constant which is experimentally defined by an equation P=(log T 2 -log T 1 )÷(log I 1 -log I 2 ), wherein T 1 and I 1 are a period of time and discharging current respectively of a nominally first depletion test of the battery and T 2 and I 2 are a period of time and discharging current respectively of a nominally second depletion test of the battery such that I 1 is greater than I 2 ; an adjusted-state-of-charge memory for storing an adjusted state-of-charge (SOC adj ) of the battery, wherein when the battery is in a fully-charged condition, the value of CCAP adj is stored therein; an adjusted-discharging-current memory for storing an adjusted discharging current (i adj ); a current meter operatively connected to the load circuit for measuring a discharging current (i) drawn from the battery; and a processor operatively connected to each of said memories and to said current meter, wherein the processor determines if i is less than or approximately equal to I; if so, then the value of i·I.sup.(P-1) is stored as i adj in the adjusted-discharging-current memory; otherwise, the value of i P is stored as i adj in the adjusted-discharging-current memory, and the processor decrements stored SOC adj based on stored i adj while battery is being discharged.

Claim 32

An accurate battery state-of-charge monitor for an electrical load circuit driven by an operatively connected battery, wherein such battery has an experimentally defined charge capacity (CCAP) which is substantially based upon a depletion test, wherein such battery in a fully-charged condition is depleted over a depletion time period (T) while drawing a predefined discharging current (I) from such battery, the monitor comprising: a state-of-charge memory for storing state-of-charge (SOC) of the battery, wherein when the battery is in a fully-charged condition, the value of CCAP is stored in the state-of-charge memory; a baseline-current memory for storing the value of I therein; an adjusted-charge-capacity memory for storing an adjusted charge capacity (CCAP adj ) of the battery, wherein CCAP adj is defined by an equation CCAP adj =T·I P , wherein P is a Peukert constant which is experimentally defined by an equation P=(log T 2 -log T 1 )÷(log I 1 -log I 2 ), wherein T 1 and I 1 are a period of time and discharging current respectively of a nominally first depletion test of the battery and T 2 and I 2 are a period of time and discharging current respectively of a nominally second depletion test of the battery such that I 1 is greater than I 2 ; an adjusted-state-of-charge memory for storing an adjusted state-of-charge (SOC adj ) of the battery, wherein when the battery is in a fully-charged condition, the value of CCAP adj is stored therein; an adjusted-discharging-current memory for storing an adjusted discharging current (i adj ); a current meter operatively connected to the load circuit for measuring a discharging current (i) drawn from the battery; and a processor operatively connected to each of said memories and to said current meter, wherein the processor determines if i is less than or approximately equal to I; if so, then the value of i·I.sup.(P-1) is stored as i adj in the adjusted-discharging-current memory; otherwise, the value of i P is stored as i adj in the adjusted-discharging-current memory, and the processor decrements stored SOC adj based on stored i adj while battery is being discharged.

Claim 33

The monitor of claim 27 further comprising a state-of-charge indicator for indicating the accurate state-of-charge of the battery based on SOC adj , the state-of-charge indicator being operatively connected to the processor.

Claim 34

The monitor of claim 27 further comprising a time-remaining indicator for indicating time remaining until the battery is substantially depleted, wherein the processor calculates the time remaining based on SOC adj and on i adj and wherein the processor is operatively connected to the time-remaining indicator.

Claim 35

A monitor as in one of claims 27-29 further comprising an average-discharging-current memory for storing an average of i, wherein the processor averages i over a defined current-averaging period of time, sets i equal to the average discharging current and stores the average discharging current in the average-discharging-current memory.

Claim 36

A monitor as in one of claims 27-29, in which a temperature sensor is located adjacent the battery and is operatively connected to the processor, the sensor for measuring the ambient temperature adjacent the battery, further comprising a nominal-operating-temperature memory operatively connected to the processor, the nominal-operating-temperature memory for storing therein a predefined nominal operating temperature (OPTEMP) of the battery, wherein if a measured ambient temperature adjacent the battery deviates from stored OPTEMP, the processor modifies stored CCAP adj to compensate for such temperature deviation.