EBike electrical

Hello,

I have a DayMak Eagle ebike. http://www.daymak.com/pages/scooters/eagle.php

My, ebike has 6 20v batteries from factory. I, would like to add an additional 2 20v batteries in parallel if possible? If yes what additions would I need to make not to kill the motor.

Thank you

I have an electric bike from https://www.eskute.co.uk/, I don't have the problem