If you haven't a body for that, you can't put pila in an ARC4+. You can only use RC123, but actually Jon SydneyB (JS Burly's) are working on a new product, not available for the moment. Throw an eye in Electronics and Batteries Forum /ubbthreads/images/graemlins/smile.gif
Or,ask Rothrandir if he wants to sell the one he made for pila 150S /ubbthreads/images/graemlins/grin.gif