Utility vehicle

1. A utility vehicle comprising:

a main frame for forming a framework of a chassis,

a ROPS provided at an intermediate portion of the main frame in a front-rear direction of a body of the utility vehicle so as to enclose a cabin,

a seat disposed inside the ROPS,

an engine disposed under the seat,

a storage box disposed under the seat and on an outside of the engine in a width direction of the utility vehicle, and

a main battery disposed inside a storage space of the storage box,

wherein the storage space has a rear storage space with a lower side space in which a sub-battery is aligned behind the main battery in the front-rear direction of the body of the utility vehicle, and an upper space in which an air cleaner is disposed over the main battery and the sub-battery.

2. The utility vehicle according to claim 1 , wherein

the seat is a rear seat, and is arranged with a front seat in two rows.

3. The utility vehicle according to claim 1 , wherein

the main battery is placed on a bottom plate installed between the main frame and a side frame extended in parallel with the main frame, and

the main battery is fixed to the bottom plate using a fixing bracket comprising a first support pillar fixed to the bottom plate on a side of the main frame, a second support pillar detachably mounted on the bottom plate on a side of the side frame, and a bridge member for connecting the first support pillar to the second support pillar.

4. The utility vehicle according to claim 3 , wherein

the bottom plate is mounted on the main frame via stays, and

a gap for drainage is provided between the main frame and the bottom plate.

5. The utility vehicle according to claim 3 , wherein

a lower end of the second support pillar is bent into an L-shape.

6. The utility vehicle according to claim 3 , wherein

the first support pillar has a U-shape angular in cross-section in a horizontal direction.

7. The utility vehicle according to claim 1 , wherein

a control unit for performing current control between the main battery and the sub-battery is disposed inside the storage box.

8. The utility vehicle according to claim 1 , wherein

the storage box has sealability.

9. The utility vehicle according to claim 1 , wherein

the sub-battery is coplanar with the main battery.

10. The utility vehicle according to claim 1 , wherein

the sub-battery is more compact in size than the main battery.

11. The utility vehicle according to claim 1 , wherein

an electric capacity of the sub-battery is smaller an electric capacity of the main battery.