Potential combination of cells neither increases the current nor the ppyential difference then what is the advantage of connectings cells in parallel?
It is safer
If the appliances are connected in series, failure of one causes the whole circuit to be broken but if connected in parallel, this does not occur
Also the equivalent internal resistance of the cell combination decreases leading to better efficiency.
(P.S bhai question sahi se likhna)
The combination could have longer life than a single of the same type.
I assume you are asking about parallel combination of batteries. That is generally not recommended for safety reasons. If one of the batteries has slightly lower output voltage, significant current from the other batteries could flow into the slightly low battery.
But if that problem were somehow managed, an advantage of using a parallel combination of batteries would be that the combination would not go dead as quickly as if you had only one battery of the required voltage.
Using a larger battery would accomplish similar longer life. I mean larger in the way that a AA battery is larger than a AAA and a D battery is larger still -- but all are 1.5 V.
I hope this helps,