Lip-8 contains a very standard 14650 battery - easy to fit in the empty case - I just worked a blade around the seam, separated the case and pulled off the spot welded terminals with care (snipe nosed pliers did the trick for me). inserted new 14650 and reassembled the case around it. - Usual disclaimer about safety - Please note that I am only describing what I did, not how to do it yourself - Lithium batteries need special care.