Contactless recharging of mobile terminal battery

1. A method of charging a battery by a contactless unit of a mobile terminal, the method performed by the contactless unit and comprising:

detecting a radio frequency (RF) field;

detecting whether a transaction is requested from a secure element, wherein the secure element is included in the mobile terminal;

determining an operation mode of the battery of the mobile terminal between a normal mode and a limit service mode according to a charging state of the battery of the mobile terminal, wherein the normal mode indicates that the battery of the mobile terminal provides power to the secure element and the contactless module and the limit service mode indicates that the mobile terminal provides a part of services of the normal mode;

transferring the power induced by the RF field to the battery of the mobile terminal when the transaction from the secure element is not requested and the operation mode is the limit service mode;

transferring the power induced by the RF field to the secure element when the transaction from the secure element is requested and the operation mode is the limit service mode; and

transferring the power to the battery of the mobile terminal when the transaction from the secure element is requested and the operation mode is the normal mode.

2. The method of claim 1 , wherein the RF field provides electromagnetic energy for inducing current used for the power.

3. The method of claim 1 , wherein the transaction is related to a contactless service or contactless function.

4. The method of claim 1 , wherein the secure element is a smart card.

5. A mobile terminal comprising:

a contactless unit that is used to perform a contactless transaction and a power source charging operation;

a battery connected with the contactless unit; and

a secure element configured to store data and to be accessed through the contactless unit, wherein the contactless unit is configured to:

detect a radio frequency (RF) field;

detect whether a transaction is requested from a secure element, wherein the secure element is included in the mobile terminal;

determine an operation mode of the battery of the mobile terminal between a normal mode and a limit service mode according to a charging state of the battery of the mobile terminal, wherein the normal mode indicates that the battery of the mobile terminal provides power to the secure element and the contactless module and the limit service mode indicates that the mobile terminal provides a part of services of the normal mode;

transfer the power induced by the RF field to the battery of the mobile terminal when the transaction from the secure element is not requested and the operation mode is the limit service mode;

transfer the power induced by the RF field to the secure element when the transaction from the secure element is requested and the operation mode is the limit service mode; and

transfer the power to the battery of the mobile terminal when the transaction from the secure element is requested and the operation mode is the normal mode.

6. The terminal of claim 5 , wherein the contactless unit comprises:

a detector that detects a presence of the electromagnetic fields;

a generator that generates current upon induction from the detected electromagnetic fields; and

a processor that cooperates with and provides control to the detector and the generator in order to provide the generated current to the power source for charging the power source.

7. The terminal of claim 6 , wherein the detector performs detection in a periodic or non-periodic manner.

8. The terminal of claim 5 , wherein the contactless transaction is related to at least one of a financial payment, transportation access, or other user application employing near-field communication (NFC) techniques.

9. The mobile terminal of claim 5 , wherein the secure element is a smart card.