BEFORE YOU BUY SOMETHING ELSE: The exact same thing happened to my Bose Soundlink Mini II in March. I went to the Bose website looking for a replacement battery. They no longer made the replacement battery. Instead, Bose gave me a great deal - they let me trade my non-functional Soundlink Mini II + a small amount of money for a brand new SoundLink Max Portable, which is maybe even better than the Soundlink Mini II.
One of the best consumer experiences I've ever had. I'm a Bose fan for life!
I’m definitely gonna try this. Thanks.