Today my master bought batteries for me. In order to power me up, you will need 6 "D" and 7 "AAA" batteries.
It is recommended to use normal alkaline batteries as the extra weight helps to stabilize my walking.
Another reason
not to use rechargeable is at this url:
http://www.roboburp.com/phpBB2/viewtopic.php?t=187&highlight=batteries