System and method for maintenance charging of battery cells
First Claim
Patent Images
1. A method for charging a battery, comprising the steps of:
- (a) charging the battery to a predetermined charge level; and
(b) applying a first maintenance voltage to the battery for a first predetermined time period, wherein the first maintenance voltage is less than a predetermined reference voltage, and wherein the first predetermined time period is a function of a self-discharge curve associated with the battery.
1 Assignment
0 Petitions
Accused Products
Abstract
A method and apparatus for maintenance charging a battery is disclosed. A battery is fully charged using conventional CC-CV techniques and subsequently is maintenance charged by applying a first maintenance voltage to the battery for a first predetermined time period. If desired, a second maintenance voltage may be applied to the battery for a second predetermined time period. An apparatus for maintenance charging a battery utilizes a timer and a charge controller to apply a maintenance voltage to a battery for a predetermined time period.
-
Citations
31 Claims
-
1. A method for charging a battery, comprising the steps of:
-
(a) charging the battery to a predetermined charge level; and
(b) applying a first maintenance voltage to the battery for a first predetermined time period, wherein the first maintenance voltage is less than a predetermined reference voltage, and wherein the first predetermined time period is a function of a self-discharge curve associated with the battery. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
applying a constant current to the battery until the battery reaches a predetermined voltage and then applying a constant voltage until the battery reaches a predetermined charge level.
-
-
3. A method according to claim 1, wherein:
-
the battery is charged to the predetermined charge level of 4.2 V; and
the first maintenance voltage of 4.15 V is applied to the battery for the first predetermined time period.
-
-
4. A method according to claim 1, wherein:
the reference voltage is a function of a self-discharge curve associated with the battery.
-
5. A method according to claim 1, wherein:
the first predetermined time period is approximately 60 hours.
-
6. A method according to claim 1, further comprising the step of:
(c) applying a second maintenance voltage for a second predetermined time period, wherein the second maintenance voltage is less than a predetermined reference voltage.
-
7. A method according to 6, wherein:
the second predetermined time period is a function of a discharge curve characteristic associated with the battery.
-
8. A method according to 6, wherein:
the second predetermined time period is approximately 200 hours.
-
9. A method according to claim 1, further comprising the step of:
iteratively reducing the first maintenance voltage for at least one predetermined time period, such that the maintenance voltage remains less than a predetermined reference voltage.
-
10. An apparatus for charging a battery cell, comprising:
-
a current source;
a timer;
a charge controller for charging the battery cell; and
a maintenance charge controller for applying a first maintenance voltage to the battery cell for a first predetermined time period, wherein the first maintenance voltage is less than a reference voltage of the battery cell in a fully-charged state, wherein the first predetermined time period is a function of a self-discharge curve associated with the battery. - View Dependent Claims (11, 12, 13, 14, 15)
the maintenance charge controller further applies a second maintenance voltage to the battery cell for a second predetermined time period, wherein the second maintenance voltage is less than the first maintenance voltage.
-
-
12. The apparatus of claim 10, wherein:
the current source comprises an ac/dc converter.
-
13. The apparatus of claim 10, wherein:
the timer, the charge controller, and the maintenance charge controller reside on the printed circuit board of a mobile communication device.
-
14. The apparatus of claim 10, wherein:
the reference voltage is a function of a self-discharge curve associated with the battery.
-
15. The apparatus of claim 10, wherein:
the maintenance charge controller iteratively reduces the first maintenance voltage for at least one predetermined time period, such that the maintenance voltage remains less than a predetermined reference voltage.
-
16. A method for charging a battery, comprising the steps of:
-
(a) charging the battery to a predetermined charge level; and
(b) applying a first maintenance voltage to the battery for a first predetermined time period, wherein the first maintenance voltage is less than a predetermined reference voltage, and wherein the reference voltage is a function of a self-discharge curve associated with the battery. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24)
applying a constant current to the battery until the battery reaches a predetermined voltage and then applying a constant voltage until the battery reaches a predetermined charge level.
-
-
18. A method according to claim 16, wherein:
-
the battery is charged to the predetermined charge level of 4.2 V; and
the first maintenance voltage of 4.15 V is applied to the battery for the first predetermined time period.
-
-
19. A method according to claim 17, wherein:
the first predetermined time period is a function of a self-discharge curve associated with the battery.
-
20. A method according to claim 16, wherein:
the first predetermined time period is approximately 60 hours.
-
21. A method according to claim 16, further comprising the step of:
(c) applying a second maintenance voltage for a second predetermined time period, wherein the second maintenance voltage is less than a predetermined reference voltage.
-
22. A method according to 16, wherein:
the second predetermined time period is a function of a discharge curve characteristic associated with the battery.
-
23. A method according to 22, wherein:
the second predetermined time period is approximately 200 hours.
-
24. A method according to claim 16, further comprising the step of:
iteratively reducing the first maintenance voltage for at least one predetermined time period, such that the maintenance voltage remains less than a predetermined reference voltage.
-
25. An apparatus for charging a battery cell, comprising:
-
a current source;
a timer;
a charge controller for charging the battery cell; and
a maintenance charge controller for applying a first maintenance voltage to the battery cell for a first predetermined time period, wherein the first maintenance voltage is less than a reference voltage of the battery cell in a fully-charged state, wherein the reference voltage is a function of a self-discharge curve associated with the battery. - View Dependent Claims (26, 27, 28, 29, 30, 31)
the maintenance charge controller further applies a second maintenance voltage to the battery cell for a second predetermined time period, wherein the second maintenance voltage is less than the first maintenance voltage.
-
-
27. The apparatus of claim 25, wherein:
the current source comprises an ac/dc converter.
-
28. The apparatus of claim 25, wherein:
the timer, the charge controller, and the maintenance charge controller reside on the printed circuit board of a mobile communication device.
-
29. The apparatus of claim 25, wherein:
the first predetermined time period is a function of a self-discharge curve associated with the battery.
-
30. The apparatus of claim 25, wherein:
the reference voltage is a function of a self-discharge curve associated with the battery.
-
31. The apparatus of claim 25, wherein:
the maintenance charge controller iteratively reduces the first maintenance voltage for at least one predetermined time period, such that the maintenance voltage remains less than a predetermined reference voltage.
Specification