STAR has an odd battery for that one. You need it split into 2 parts - the front half (with the plug) in a 2 cell X 2 cell configuration, and the rear half in a 2 cell + 1 horizontal cell configuration. It will only take an 8.4 volt setup.
This is the setup you will need, although you may go with more MAH:
http://www.wgcshop.com/pcart/shopper...00L85_srch_l85