Clinton; I have the I beam w/ the ltl bag on my Guild J30. While it is still a pain to change the Battery. yepper loosen string an fiddle with it. It is nicer to not have to mess w/ the circut board. The battery bag is only a small bag made of nylon with velcrow on it which sticks to a piece of velcrow place on the guitar. Mine is along side the neck, I hate to see wires inside the sound hole.

From the Baggs factory the wires are soldered into the board. While I have not heard of the battery bag add on. My personal estimation is to go along with John's advice and make the connector and battery bag at home and still change batts intermittently while restringing.

Gary®