kv rating

[BrianG]

For most motors, you want to keep the total rpms at or below between 30,000-35,000 rpm for best efficiency. So, you just divide 35000 (max rpm) by the kv to get the desired voltage. Then you divide that by 1.2 for NiMH cells or 3.7 for Lithium cells.

For 16 cells, that would be over 53k - a bit on the high side. I'd stick to right about 12 cells if it were me.