Inverter

1. An inverter, comprising:

a case having a receiving part in which a battery pack is to be received;

a control part disposed within the case to convert a voltage of the battery pack into a preset output voltage;

a connection part disposed in the receiving part at a bottom thereof, the connection part having a shape corresponding to a plug on a bottom of the battery pack and directly electrically connecting the battery pack to the control part; and

an external terminal electrically connected to the control part and disposed on the case,

wherein the preset output voltage converted by the control part is output through the external terminal.

2. The inverter as claimed in claim 1 , further comprising a guide on a surface of the receiving part.

3. The inverter as claimed in claim 2 , wherein the guide has a shape corresponding to a guide groove of the battery pack.

4. The inverter as claimed in claim 1 , further comprising a power selection part electrically connected to the control part to select AC power or DC power.

5. The inverter as claimed in claim 1 , further comprising a voltage selection part electrically connected to the control part to select an output voltage.

6. The inverter as claimed in claim 1 , wherein the control part includes a radio-frequency identification (RFID) receiver for communicating with an RFID transmitter in the battery pack, the RFID receiver receiving information transmitted from the RFID transmitter to identify whether the battery pack is mounted in the inverter.

7. The inverter as claimed in claim 1 , wherein the control part further comprises a voltage detector configured to detect a voltage of the battery pack.

8. The inverter as claimed in claim 7 , wherein the voltage detector prevents the voltage of the battery pack from being used when the voltage of the battery pack is less than a reference voltage.

9. The inverter as claimed in claim 8 , wherein the voltage detector generates an alarm when the voltage of the battery pack is less than a reference voltage.

10. The inverter as claimed in claim 1 , wherein the battery pack is to be mounted on a mobile device.

11. The inverter as claimed in claim 1 , wherein the control part converts DC voltage charged in the battery pack into AC voltage or DC voltage.

12. The inverter as claimed in claim 1 , further comprising a power selection part disposed outside the case, the power selection part allowing a user to select a type of power to be supplied.

13. The inverter as claimed in claim 12 , further comprising a voltage selection part disposed outside the case, the voltage selection part allowing a user to select a voltage to be supplied.

14. A system, comprising:

a battery pack; and

an inverter as claimed in claim 1 .

15. A mobile device, comprising the system as claimed in claim 14 .