Systems and methods for determining battery parameters following active operation of the battery
First Claim
1. A method comprising:
- determining a model function of a battery describing voltage relaxation response after load termination;
monitoring a load current of the battery;
determining when the load current is less than a threshold current indicating load termination;
only in response to load termination adapting parameters of a voltage response of the battery associated with the load current to achieve the best fit to the model function to obtain parameters of an equivalent battery circuit; and
storing the parameters in memory.
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Accused Products
Abstract
When the load of a battery powered device is removed or significantly reduced, the voltage response may be recorded or analyzed in real time. The parameters of a battery'"'"'s equivalent circuit can be found by fitting recorded or real time voltage response to a model function. The model function may describe the equivalent circuit voltage response to the load transition through equivalent circuit parameters. The model function may account for a duration of a load application prior to a transition as well as values of the load before and after the transition. Response of battery voltage to load application or load release is time dependent. Modeling of this time dependence can provide significant advantages in fuel gauging implementation, for example, to significantly reduce the waiting time before measured voltages can be used for state of charge (SOC) correlation and to improve the accuracy of the prediction of run-time for devices that drain a battery in short high-current pulses.
19 Citations
20 Claims
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1. A method comprising:
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determining a model function of a battery describing voltage relaxation response after load termination; monitoring a load current of the battery; determining when the load current is less than a threshold current indicating load termination; only in response to load termination adapting parameters of a voltage response of the battery associated with the load current to achieve the best fit to the model function to obtain parameters of an equivalent battery circuit; and storing the parameters in memory. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A non-transitory computer readable medium containing computer instructions stored therein for causing a computer processor to perform the steps comprising:
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selecting an equivalent circuit for a battery describing voltage relaxation response after load termination; determining a Laplace domain equation of the equivalent circuit; determining a time domain function for a load current of the equivalent circuit; determining a Laplace transform of the time domain function for the load current of the equivalent circuit; determining a voltage response of the equivalent circuit; determining a time domain response function of the voltage response; and determining parameters of the equivalent circuit by fitting the time domain response function to voltage relaxation data obtained only after a termination of a load pulse. - View Dependent Claims (12, 13, 14, 15)
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16. A system comprising:
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a processor configured to;
monitor a load current of a battery;
determine when the load current is less than a threshold current indicating load termination;adapt parameters of a voltage response of the battery associated with the load current to a model function of the battery to achieve the best fit only after load termination to obtain parameters of an equivalent battery circuit; and memory configured to store the parameters. - View Dependent Claims (17, 18, 19, 20)
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Specification