Based on a rider weight of 90kg or 14 stone, on smooth, flat terrain with no added weight e.g. pannier bags the distances are as follows;
36/9 battery 25-30 miles,
36/11 battery 30-35 miles,
36/15 battery 40-45 miles.
36/17 battery 45-50 miles.
These will vary slightly depending on the level of assistance given by the motor and the use of a throttle.
48 volt batteries will drain faster due to the higher wattage and voltage of the motor it is connected to.