Bonjour BigBuzz666
I prefer to use LiPO batteries in my PTW. I bought this type of battery, see this
link. In my opinion the LiPO battery technology is the best.
The fit is tight but they do fit in the crane stock of the PTW. When removing the battery you should use your finger to push the battery out of the crane stock rather then pulling on the battery wires until the battery's plastic wrap smoothes out.
Good luck.