METHOD FOR CHARGING A BATTERY USING A CONSTANT CURRENT ADAPTED TO PROVIDE A CONSTANT RATE OF CHANGE OF OPEN CIRCUIT BATTERY VOLTAGE
First Claim
1. A method for charging a battery, wherein the battery includes an enclosure, comprising the steps of:
- (a) providing an approximately constant current to the battery;
(b) performing successive sampling operations of a first characteristic of the battery;
(c) in response to the successive sampling operations, determining a one or more parameters of the battery;
(d) comparing the value of the one or more parameters with a first predetermined value;
(e) modifying the value of the approximately constant current supplied to the battery in response to a difference between the value of the one or more parameters and a first predetermined value; and
(f) repeating the method from step (a) until the value of the first characteristic of the battery is determined to be equal to or greater than a second predetermined value.
7 Assignments
0 Petitions
Accused Products
Abstract
A method for charging a battery is disclosed, wherein a constant current charging current is periodically adjusted as needed such that the change in battery voltage increases approximately linearly during the charging period. In some embodiments the charging is in three phases. An optional first phase charges with a low current until the battery voltages rises to a certain minimum. During a second phase a constant current is provided while the battery voltage is monitored. The second phase constant current is periodically increased if the rate of change of battery voltage is less than a predetermined value and is decreased if the rate of change of battery voltage is more than the predetermined value. When the battery voltage attains a predetermined value, a third phase begins wherein a constant voltage is applied to the battery while the battery current draw is periodically monitored. Charging is stopped when the battery current draw falls to a predetermined value or, in some embodiments, when the charging current drops to a value that is a certain percentage of the charging current at the termination of phase two.
In one embodiment the battery voltage is monitored to determine a possible battery failure, for example in the case of the battery voltage decreasing during the constant current charging of phase two. In some embodiments the battery is shorted out in response to detection of a possible failure.
-
Citations
19 Claims
-
1. A method for charging a battery, wherein the battery includes an enclosure, comprising the steps of:
-
(a) providing an approximately constant current to the battery; (b) performing successive sampling operations of a first characteristic of the battery; (c) in response to the successive sampling operations, determining a one or more parameters of the battery; (d) comparing the value of the one or more parameters with a first predetermined value; (e) modifying the value of the approximately constant current supplied to the battery in response to a difference between the value of the one or more parameters and a first predetermined value; and (f) repeating the method from step (a) until the value of the first characteristic of the battery is determined to be equal to or greater than a second predetermined value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
-
13. A method for detecting possible failure of a battery being charged, wherein the battery includes an enclosure, comprising the steps of:
-
(a) performing successive sampling operations of a characteristic of the battery; (b) in response to the successive sampling operations, determining a parameter of the battery; (c) repeating the method from step (a) unless the value of the parameter violates a rule; and (d) in response to the value of the parameter violating the rule, taking a corrective action. - View Dependent Claims (14, 15, 16, 17, 18, 19)
-
Specification