I got a replacement battery for JAWBONE Big from ebay, it works great! here is the link:
I got a replacement battery for Bose SOUNDLINK Mini fromebay, it works great! here is the link:
And it also has battery for SOUNDLINK I II III...
http://www.ebay.com/itm/322588700358?ul_... :Here is someone who made and sell the battery for Jambox and Big Jambox, i hope this could be helpful