Patent Application
20100060237
1. Technical field
The present invention relates to battery discharge circuits and discharge methods thereof, and particularly to a battery discharge circuit and discharge method thereof that can completely release the power of a battery.
2. Description of the Related Art
Mobile communication has been playing an important role in the rapidly developed technological fields. Users place more reliance on mobile phones than ever, since mobile phone enables a user to keep contact with others at any place and at any time. A mobile phone obtains almost all of its operating power from a rechargeable battery.
In use, the battery outputs an output voltage to support the mobile phone working at an optimal working status. The output voltage should be higher than a work voltage of the mobile phone to activate the mobile phone. The output voltage of the battery drops as the battery works. When the output voltage falls below the work voltage, the mobile phone stops working and the battery stops discharging.
Overdischarge occurs when the battery continues to discharge even when the output voltage is below an end voltage. Overdischarge always causes irreversible damage to the battery and should be avoid.
Typically, the work voltage is higher than the end voltage, so that overdischarge can be avoid. However, since the work voltage is higher than the end voltage, the battery can not completely discharge and always retains some energy therein. Thus, the battery does not release power effectively enough.
Therefore, there is a room for improvement within the art.
Many aspects of the exemplary battery discharge circuit and discharge method thereof can be better understood with reference to the following drawings. These drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the exemplary battery discharge circuit and discharge method thereof. Moreover, in the drawings like reference numerals designate corresponding parts throughout the several views. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like elements of an embodiment.
The present battery discharge circuit is suitably assembled within a portable electronic device, such as a lap computer, a mobile phone, a personal digital handset, or the like.
Referring to
The battery 10, can be a lithium ion (Li+) battery, is rechargeable, and configured to provide power to the power supply manager 30. The battery 10 defines an output voltage (Vout), a work voltage (Vwork) and an end voltage (Vend). Vout initially is higher than Vwork to activate the electronic device to work, and then drops as the battery 10 discharges. Vwork is a lowest voltage enabling the electronic device to work. Vend is a threshold voltage after which overdischarge occurs when the battery 10 continues to discharge under the condition that Vout is lower than Vend. For instance, Vwork and Vend of a Li+ battery used in a mobile phone are about 3.6V and 2.5V, respectively.
The battery protecting module 21 is configured to monitor Vout of the battery 10, and shut down the connection between the battery 10 and the power supply manager 30 to terminate discharge of the battery 10 when Vout falls below Vend to protect the battery 10 from damage of overdischarge. The battery protecting module 21 includes a detecting unit 211 and a switch unit 213. The detecting unit 211 electronically connects with the battery 10, monitors Vout of the battery 10, compares Vout and Vend, and outputs a trigger signal to the switch unit 213 when Vout drops to Vend. The switch unit 213 is used to control discharge of the battery 10, and connects with the detecting unit 211. When Vout is higher than Vend, the switch unit 213 is on a turn-on mode, which means there is current flow passing therethrough. When the switch unit 213 receives the trigger signal which means Vout drops to Vend, the switch unit 213 turns to a cut-off mode and there is no current flow passing therethrough thereby terminating discharge of the battery 10. Therefore, overdischarge of the battery 10 can be prevented by using the battery protecting module 21.
The voltage adjusting module 23 is used to boost Vout to Vwork when Vout falls below Vwork, and includes a voltage comparison unit 231 and a conventional voltage booster unit 233. The voltage comparison unit 231 serially connects between the switch unit 213 and the power supply manager 30, and the voltage booster unit 233 serially connects between the voltage comparison unit 231 and the power supply manager 30. The voltage comparison unit 231 receives Vout from the switch unit 213, compares Vout with Vwork, and selectively transfers Vout to the power supply manager 30 or to the voltage booster unit 233 in response to the comparison result. The voltage comparison unit 231 transfers Vout directly to the power supply manager 30 when Vout is higher than Vwork, otherwise the voltage comparison unit 231 transfers Vout to the voltage booster unit 233. The voltage booster unit 233 receives Vout, boosts Vout to Vwork and then transfers the boosted Vout to the power supply manager 30.
The power supply manager 30 receives voltage from the battery discharge module 20, and converts the received voltage to several varied voltages to corresponding components of the electronic device to enable the electronic device. The power supply manager 30 is activated to work when received the work voltage.
Referring to
S1: Providing a Vout by discharge of a battery 10.
S2: Detecting Vout by a voltage detecting unit 211 of a battery protecting module 21.
S3: Comparing Vout with Vend and selectively turn on or cut off the switch unit 213 in response to the comparison result, wherein turn on the switch unit 213 and goes to step S5 if Vout is higher than Vend, otherwise goes to step S4.
S4: Cut off the switch unit 213, thus terminating discharge of the battery 10.
S5: Comparing Vout with Vwork, wherein Vout is compared with Vwork by a voltage comparison unit 231 of a voltage adjusting module 23, and selectively output Vout or transfer Vout to a conventional voltage booster unit 233 of the voltage adjusting module 23 in response to the comparison result, wherein goes to step S7 to output Vout if Vout is higher than Vwork, otherwise goes to step S6 to transfer Vout to the voltage booster unit 233.
S6: Boosting Vout to Vwork by the voltage booster unit 233.
S7: Output Vout and return to step 2.
In the exemplary embodiment of the present invention, overdischarge of the battery 10 can be avoid by using battery protecting module 20. In addition, the amount of energy of the battery 10 during Vout drops from Vwork to Vend can be effectively used by using the voltage booster unit 233.
It is to be understood, however, that even though numerous characteristics and advantages of the exemplary invention have been set forth in the foregoing description, together with details of the structure and function of the exemplary invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of exemplary invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 200810304395.9 | Sep 2008 | CN | national |
