This is a major issue with this product. SoundLink® Mini Bluetooth® speaker II
Red light flashes. Unit will not power up. Battery in sleep mode - (Lithium undervolt shutdown). Unable to by-pass battery and power up via mains. Unable to link with computer to do the famous firmware upgrade everyone mentions. (My firmware is up to date anyway)
I got lateral and wondered if I could use some generic lithium wake up techniques for batteries in other applications such as drills. Trouble is.... the bloody battery is hard wired onto the motherboard (???????) WTF
When was the last time you saw that? I'm not going to risk the motherboard while messing with the battery.
I've looked all over the web for DIY advice, and the closest thing to an answer has been here, above: 'send it in for service'. Doesn't that just totally fly in the face of this site?