A fully charged cell of emf 6.0 V delivers a constant current of 5.0 A for a time of 0.25 hour until it is completely discharged. The cell is then re-charged by a rectangular solar panel of dimensions 0.40 m 0.15 m at a place where the maximum intensity of sunlight is 380 W m2 .

The overall efficiency of the re-charging process is 18 %. Calculate the minimum time required to re-charge the cell fully.