Battery module array comprising under-base bar

1. A battery module array, comprising:

a plurality of battery modules, each including two secondary battery cells, a module frame, and a cooling fin;

end plates located at both side surfaces of a battery module assembly in which the plurality of battery modules are assembled;

a u-shaped tension bar contacting an upper end of the battery module assembly and fixed to the end plates;

a front sensing unit including sensing bus bars electrically connected to electrode leads of the battery modules included in the battery module assembly, a terminal bus bar, and a housing, the front sensing unit being located at a front portion of the battery module assembly;

a rear sensing unit including sensing bus bars electrically connected to the electrode leads of the battery modules included in the battery module assembly, and a housing, the rear sensing unit being located at a rear portion of the battery module assembly;

at least one under-base bar located at a lower end of the battery module assembly and fixed to the end plates;

a front cover configured to keep the front portion of the battery module assembly from being exposed to outside; and

a rear cover configured to keep the rear portion of the battery module assembly from being exposed to outside.

2. The battery module array according to claim 1 , wherein the battery module array includes two under-base bars, and

the two under-base bars are:

a first under-base bar located at a front lower end of the battery module assembly; and

a second under-base bar located at a rear lower end of the battery module assembly, respectively.

3. The battery module array according to claim 1 , wherein the end plates and the under-base bars are fixed by bolts.

4. The battery module array according to claim 1 , wherein the module frame has a rectangular frame shape, has a slit formed in a lower surface thereof to allow the cooling fin to be inserted therethrough, and is interposed between the two secondary battery cells.

5. The battery module array according to claim 1 , wherein the battery module array further includes an insulating sheet interposed between the battery module assembly and the end plates.

6. The battery module array according to claim 5 , wherein the insulating sheet is made of ethylene propylene diene monomer (EPDM) rubber.

7. The battery module array according to claim 1 , wherein the u-shaped tension bar is provided in plurality as two u-shaped tension bars arranged in parallel,

the end plates have grooves with threads formed therein,

the u-shaped tension bars have grooves formed at locations corresponding to the grooves of the end plates, and

the end plates and the u-shaped tension bars are fixed by a bolt.

8. The battery module array according to claim 1 , wherein the front sensing unit as well as the rear sensing unit includes a connector connectible with an external device.

9. The battery module array according to claim 1 , wherein the front cover includes an electrode terminal electrically connected with the terminal bus bar, and

the electrode terminal is exposed to an outer surface of the front cover.

10. A battery pack, comprising:

a battery module array defined in claim 1 ; and

a battery protection circuit.

11. A battery-driven system, comprising:

a battery pack as defined in claim 10 ; and

a load supplied with power from the battery pack.

12. The battery-driven system according to claim 11 , wherein the load is an electrically-driven means or a portable device.