Why rechargeable battery (AA,AAA,C,D) have to be 1.25 volt?

Question

Why are the rechargeable battery have the voltage lower than the non-rechargeable dry-cell.

Answer 1

the wet-cell battaries need to be recharged and therefore need lower voltage. the drey cell has high voltage to sustain it throughout all the time it is bieng used. too much energy in wet-cell may cause an acid leak in the battaries or explosion.