A battery cell assembly having first, second, and third battery cells and a unitary wrapping sheet is provided. The unitary wrapping sheet is disposed on a top surface and a bottom surface of the first battery cell. The unitary wrapping sheet is further disposed on a top surface and a bottom surface of the second battery cell. The unitary wrapping sheet is further disposed on a top surface and a bottom surface of the third battery cell. The unitary wrapping sheet is further disposed on and encloses a portion of a combined periphery of the first, second, and third battery cells such that the top surface of the first battery cell, the top surface of the second battery cell, and the top surface of the third battery cell are held substantially parallel to one another.