well, if you want to be technical....the 4x 2v cells in an 8v battery are equivilant to the 8x 2v cells in a 16v battery. the important thing to look at is the overall capacitance of each battery. two 16v battery's is no better than 2 8v unless the 16v battery being used has a higher capacitance than the 8v its being compared to.

 

btw....Richard, what are you doing with the rabbit?