Hi, I have the same problem, even if the battery is charged, although for some unknown reason it does tend to self discharge over a couple of weeks. The only solution I’ve found that always works for me , even if it is fully charged is to attach a charger for a short period of time, a minute is usually enough. If you then disconnect the charger you’ll be able to switch it on, it’s almost as if it goes into some sort of deep sleep mode. Mine is a version 1 of this speaker, friends who have the SoundLink II don’t seem to experience this problem