Motor duty UPS is capable of delivering the high starting current demand of the induction motor. Bypass power supply is synchronized with the UPS output (via static bypass switch) to provide the additional current during motor starting. In most of the cases, motor is started only when the main supply is available. This helps in optimizing the UPS rating. Battery backup is used to keep the motor running in the event of power failure until the alternate power supply comes online. Hence in my opinion, no special battery is needed for motor duty UPS. Battery selection criteria can be same as that of a normal UPS, which is based on the budget, autonomy time, battery life expectancy, ambient temperature, maintenance scenario etc.