My G10 had just passed its warranty when the battery went dead. In fact, I had two other G10s that also died just after the warranty period. As I said, this one sat dead for about three years before I found a battery that works. I did the battery replacement safely, and can now use the transmitter again.
Having a battery that is not "user-serviceable" and that, in fact, can't even be purchased in the US, left me with the option of tossing the G10 (which I did with the other two), or finding a way to save some of my investment in the third one. I did the replacement safely, and it works. And you'll notice my last sentence in the original post, where I urge caution and being safe if the replacement is attempted.
I appreciate your comments, but there are lots of us out there with dead, expensive units that CAN be salvaged. Had there been a way to get the battery or unit replaced through Line6 (I tried), I would have availed myself of it.
Regards,
Carl
Owner of many Line6 products since about 1996, or whenever that first Pod came out