You need 12v.

Go buy yourself one of these:

BH181 For (8) D Cell with Solder Lug Connection.
BH181 For (8) D Cell with Solder Lug Connection $3.95
http://www.action-electronics.com/batteryholders.htm





Or...if you have a 12v charger, get a 12v lead acid battery:
http://www.radioshack.com/product/in...LAID=107600087