Battery end of life determination
View Patent ↗A method for determining an end of life of a battery includes determining a discharge capacity of the battery at a given moment in time, determining a discharge capacity at a functional endpoint of the battery, and determining a fuel remaining in the battery at the given moment in time as a function of both the discharge capacity at the given moment in time and the discharge capacity of the battery at the functional endpoint of the battery. The determined fuel remaining is indicative of an end of life of the battery.
1. A method for determining an end of life of a battery, comprising:
determining a discharge capacity of the battery at a given moment in time;
determining a discharge capacity at a functional endpoint of the battery; and
determining a fuel remaining in the battery at the given moment in time as a function of both the discharge capacity at the given moment in time and the discharge capacity of the battery at the functional endpoint of the battery, wherein the determined fuel remaining is indicative of an end of life of the battery.
2. The method of claim 1 , further including determining a fuel remaining in the battery as a function on the following:
1
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(
discharge
capacity
at
the
given
moment
in
time
discharge
capacity
of
the
battery
at
the
functional
endpoint
)
.
3. The method of claim 1 , further including determining the discharge capacity at the functional endpoint of the battery as a function of both the determined discharge capacity of the battery at the given moment in time and a closed circuit voltage of the battery.
4. The method of claim 1 , further including determining a closed circuit voltage of the battery, wherein the discharge capacity at the functional endpoint of the battery is a function of both the discharge capacity of the battery at the given moment in time and the closed circuit voltage of the battery.
5. The method of claim 1 , wherein the discharge capacity at the given moment in time is determined via coulomb counting.
6. The method of claim 1 , further including:
determining a temperature of about the battery;
determining the discharge capacity at the functional endpoint of the battery as a function of the determined temperature.
7. The method of claim 1 , further including:
determining a closed circuit voltage of the battery;
determining a temperature of about the battery;
determining the discharge capacity of the battery at the given moment in time as a function of both the determined closed circuit voltage and the determined temperature.
8. The method of claim 1 , further including outputting a signal when the determined fuel remaining is below a preset fuel threshold, wherein the signal is indicative of the fuel remaining.
9. The method of claim 8 , wherein the signal is at least one of a visual and an audio message.
10. The method of claim 1 , wherein the method is executed in a battery-powered device, and further including automatically shutting down: the battery-powered device when the determined fuel remaining is below a preset fuel threshold.
11. The method of claim 10 , wherein the battery-powered device uses power from the battery to operate at least one electrical component of the battery powered device.
12. The method of claim 10 , wherein the battery-powered device includes at least one light source and the power from the battery is used to illuminate the light source.
13. The method of claim 1 , further including:
determining a chemistry of the battery; and
determining the fuel remaining in the battery as a function of all three of the discharge capacity at the functional endpoint of the battery, the discharge capacity of the battery, and the chemistry of the battery.
14. The method of claim 1 , wherein the method is employed to fuel gauge a battery of an electrical device, and further including:
providing a low battery warning when the determined fuel remaining in the battery is below a first preset set fuel level; and
powering down the electrical device when the determined fuel remaining in the battery is below a second preset set fuel level, wherein the first preset threshold is greater than the second preset threshold.
15. A method for determining an end of life of a battery, comprising:
determining an end of life of a battery based on both a discharge capacity at a functional endpoint of the battery and a discharge capacity at a given time, wherein the discharge capacity at a given time is determined via coulomb counting;
wherein the end of life of the battery is a function of:
1−( Q m /Q FE )
wherein Q m is the discharge capacity at the given time and Q FE is the discharge capacity at the functional endpoint of the battery; and
wherein the discharge capacity at the functional endpoint is computed based on a closed circuit voltage of the battery and the discharge capacity at a given time.
16. The method of claim 15 , wherein the discharge capacity at the functional endpoint is a function of:
( A×Q m 2 )+( B ×CCV 2 )+( C×Q m ×CCV)+( D×Q m )+( E ×CCV)+ F,
wherein A, B, C, D, E and F are fitting constants, Q m is the discharge capacity at the given time, and CCV is the closed circuit voltage of the battery.
17. A method for determining an end of life of a battery, comprising:
determining an end of life of a battery based on both a discharge capacity at a functional endpoint of the battery and a discharge capacity at a given time, wherein the discharge capacity at a given time is determined based on both a closed circuit voltage of the battery and a temperature about the battery; and
wherein the end of life of the battery is a function of:
1−( Q m /Q FE ),
wherein Q m is the discharge capacity at the given time and Q FE is the discharge capacity at the functional endpoint of the battery.
18. The method of claim 17 , wherein the discharge capacity at the functional endpoint is a function of:
( A×T 3 )+( B×T 2 )+( C×T )+ D,
wherein A, B, C and D are fitting constants and T is the temperature.
19. The method of claim 17 , wherein the discharge capacity at the given moment in time is a function of:
( A ×CCV× T 2 )+( B ×CCV 2 )+( C×T )+( D×T ×CCV)+( E ×CCV)+( F×T )+ G,
wherein A, B, C, D, E, F and G are fitting constants, CCV is the closed circuit voltage and T is the temperature.
20. A battery powered appliance, comprising:
memory that stores battery fuel gauging instructions;
a battery receiving region configured to receive at least one battery, wherein the battery receiving region includes at least one electrical contact that electrically communicates with a battery inserted into the battery receiving region; and
a processor in operative communication with the memory and the at least one electrical contact of the battery receiving region;
wherein the processor causes execution of the battery fuel gauging instructions, which determines a remaining life of the battery installed in the battery receiving region based at least in part on information about the battery obtained via the at least one electrical contact, and the processor invokes at least one action when the determined remaining life of the battery is below a preset fuel level; and
wherein the battery fuel gauging instructions determine the remaining life of the battery as a function of both a discharge capacity of the battery and an expected discharge capacity at a functional endpoint of the battery.
21. The battery powered appliance of claim 20 , further including at least one light source, wherein the at least one light source is illuminated with power supplied by the battery.
22. The battery powered appliance of claim 20 , further including an output component that outputs a signal indicative of the determined remaining life of the battery.
23. The battery powered appliance of claim 20 , wherein the at least one action includes at least one of outputting a signal indicative of the determined remaining life of the battery or powering down the battery powered appliance.
24. The battery powered appliance of claim 20 , further including a battery chemistry determiner that determines a chemistry of the battery in electrical communication with the at least one electrical contact of the battery receiving region, wherein the memory also stores at least two sets of battery fuel gauging coefficients employed in connection with the battery fuel gauging instructions, wherein the at least two sets of coefficients are tuned to two different battery chemistries, and the set of coefficients employed is based on the determined battery chemistry.
25. The battery powered appliance of claim 20 , wherein the at least one battery consists essentially of a lithium-based primary electrochemical cell.
26. The battery powered appliance of claim 25 , wherein the at least one battery consists essentially of a lithium-iron disulfide electrochemical cell.
27. The battery powered appliance of claim 20 , wherein the battery response to changes in load in conjunction with battery open circuit voltage and closed circuit voltage are used to determine the battery chemistry.