Here's the post for reference:
Bose Tech Support wrote:Hi, Everyone.
Thanks for being patient.
If your S1 Pro system battery is draining when the system is not in use and not connected to AC power, please contact Bose Support. They will work with you to get your S1 system repaired.
Bose® Product & Technical Support at (877) 335-2673
(U.S. and Canada only)
Monday-Friday: 9:00 AM - 9:00 PM ET
The local Bose Support representatives can answer any further questions.
For those in the UK, the appropriate contact details are:
Bose Support UK
Tel 01634 224 288 (Mon - Fri: 09:00-18:30, Sat 09:00-17:00 GMT)