Accurate battery state-of-charge monitoring and indicating apparatus and method
First Claim
1. 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 (ieff) equal to i;
otherwise setting ieff equal to K·
iP, 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 ieff while discharging the battery.
7 Assignments
0 Petitions
Accused Products
Abstract
The apparatus and method of monitoring and/or indicating an accurate state-of-charge of a battery compensates for varying current loads and changing temperature conditions. The apparatus and method compensate for the Peukert Effect which manifests itself when varying current loads are applied to the battery. Also, the apparatus and method may compensate for temperature changes in the environment of the battery. The extent of the Peukert Effect and temperature variation on the battery is based on intrinsic characteristics of the battery which may be experimentally defined. Specifically, preferred apparatuses include memories for storing various discharging/charging related values and a processor to calculate and determine values related to accurately monitoring the battery'"'"'s state-of-charge. Also, the apparatus may include a battery state-of-charge indicator including a multi-segmented, multi-color LED display. The apparatuses and methods use a battery having a state-of-charge equal to the battery'"'"'s charge capacity (CCAP). The battery'"'"'s state-of-charge is tracked as it discharges/charges. Preferably, if the discharging current (i) is greater than or equal to a predefined discharging current (I), then the Peukert Equation is utilized to determine the actual discharge of the battery. If I<i, then Peukert Equation is not utilized because the Peukert Effect is not exhibited when i is below I.
131 Citations
31 Claims
-
1. 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 (ieff) equal to i;
otherwise setting ieff equal to K·
iP, 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; anddecrementing SOC based on ieff while discharging the battery. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. 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 (CCAPadj) substantially based upon an equation CCAPadj =T·
IP, wherein P is a Peukert constant which is experimentally defined by an equation P=(log T2 -log T1)÷
(log I, -log I2), wherein T1 and I1 are a period of time and discharging current respectively of a nominally first depletion test of the battery and T2 and I2 are a period of time and discharging current respectively of a nominally second depletion test of the battery such that I1 is greater than I2 ;storing value of CCAPadj as an adjusted state-of-charge (SOCadj in a memory associated with SOCadj ; 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 (iadj) equal to i·
I.sup.(P-1) ;
otherwise, setting iadj equal to iP ; anddecrementing SOCadj based on iadj while discharging the battery. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15)
-
-
16. 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 (CCAPadj) which is satisfied by an equation CCAPadj =T·
IP, wherein P is a Peukert constant which is experimentally defined by an equation P=(log T2 -log T1)÷
(log I1 -log I2), wherein T1 and I1 are a period of time and discharging current respectively of a nominally first depletion test of the battery and T2 and I2 are a period of time and discharging current respectively of a nominally second depletion test of the battery such that I1 is greater than I2, which CCAPadj 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 SOCadj stored in an associated memory, wherein SOCadj 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 (zadj) equal to z; producing a charging compensation factor (COMF) wherein COMF is defined by an equation COMF=SOCadj ÷
SOC;modifying zadj so that zadj =zadj ·
COMF·
CEF, wherein CEF is a defined charging efficiency factor of the battery;incrementing SOCadj based on zadj while charging the battery. - View Dependent Claims (17, 18, 19, 20, 21)
- a method of monitoring an accurate state-of-charge of a battery comprising;
-
22. 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 (ieff); 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 ieff in the effective-discharging-current memory;
otherwise, the value of K·
iP is stored as ieff 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 ieff while battery is being discharged. - View Dependent Claims (23, 24, 25, 26)
-
-
27. 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 (CCAPadj) of the battery, wherein CCAPadj is defined by an equation CCAPadj =T·
IP, wherein P is a Peukert constant which is experimentally defined by an equation P=(log T2 -log T1)÷
(log I1 -log I2), wherein T1 and I1 are a period of time and discharging current respectively of a nominally first depletion test of the battery and T2 and I2 are a period of time and discharging current respectively of a nominally second depletion test of the battery such that I1 is greater than I2 ;an adjusted-state-of-charge memory for storing an adjusted state-of-charge (SOCadj) of the battery, wherein when the battery is in a fully-charged condition, the value of CCAPadj is stored therein; an adjusted-discharging-current memory for storing an adjusted discharging current (iadj); 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 iadj in the adjusted-discharging-current memory;
otherwise, the value of iP is stored as iadj in the adjusted-discharging-current memory, and the processor decrements stored SOCadj based on stored iadj while battery is being discharged. - View Dependent Claims (28, 29, 30, 31)
-
Specification