Charging regime at any state of charge using the first derivative of temperature and the first and second derivative of voltage with respect to time
AssigneeCobasys, LLC
InventorChristopher M. Ciaramitaro
Life of this patent
Estimating the term…
Abstract
A battery control module for a rechargeable battery includes a voltage measuring module that measures a voltage of the rechargeable battery and that estimates a first derivative of the voltage with respect to time (dV/dt) and a second derivative of the voltage with respect to time (d2V/dt2). A charge control module estimates a maximum charging current based on dV/dt. A current control module limits a charging current of the rechargeable battery to the maximum charging current and turns off the charging current when d2V/dt2 is greater than dV/dt.
Claims25
A battery control module for a rechargeable battery, comprising:
- a voltage measuring module that measures a voltage of the rechargeable battery and that estimates a first derivative of the voltage with respect to time (dV/dt) and a second derivative of the voltage with respect to time (d2V/dt2);
- a charge control module that estimates a maximum charging current based on dV/dt;
- and
- a current control module that limits a charging current of the rechargeable battery to the maximum charging current and that turns off the maximum charging current when d2V/dt2 is greater than dV/dt.
A battery control module for a rechargeable battery, comprising:
- a voltage measuring module that measures a voltage of the rechargeable battery and that estimates a first derivative of the voltage with respect to time (dV/dt);
- a charge control module that estimates a maximum charging current based on dV/dt;
- a temperature measuring module that measures a temperature of the battery, estimates a first derivative of the battery temperature with respect to time (dT/dt), and communicates with the charge control module;
- and
- a current control module that limits a charging current of the rechargeable battery to the maximum charging current and that reduces the maximum charging current from an initial value while dT/dt is less than a predetermined rate and dV/dt is positive and decreasing.
A method of recharging a rechargeable battery, comprising:
- measuring a voltage of the rechargeable battery;
- estimating a first derivative of the voltage with respect to time (dV/dt) and a second derivative of the voltage with respect to time (d2V/dt2);
- establishing a charging current limit based on dV/dt;
- limiting a charging current of the rechargeable battery to the charging current limit;
- and
- turning off the charging current when d2V/dt2 is greater than dV/dt.
A method of charging a rechargeable battery, comprising:
- measuring a voltage of the rechargeable battery;
- estimating a first derivative of the voltage with respect to time (dV/dt);
- estimating a maximum charging current based on dV/dt;
- measuring a temperature of the battery;
- estimating a first derivative of the battery temperature with respect to time (dT/dt);
- limiting a charging current of the rechargeable battery to the maximum charging current;
- reducing the maximum charging current from an initial value while dT/dt is less than a predetermined rate and dV/dt is positive and decreasing.
Dependencies are inferred from the claim text.