Hi @rick11 ,
You said that it has only been used 5 or 6 times. How old it the unit and have you had it since new?
Depending on where you bought it etc there is usually a 1 year (12 month) manufacturer's warranty on the speaker (unfortunately only 90 days in the USA).
Check the user manual or online, for the warranty details pertaining to your location.
If the warranty period is still valid, I suggest going the warranty route first to get it fixed, replaced etc, before opening the speaker to check what may be wrong. Opening the speaker will void the warranty.
If the warranty period is over then you may have to open the speaker to check for any obvious problems e.g. burnt out components or loose connections etc.
Here’s the Ifixit SRS-XB22 Battery Replacement guide. It is useful as it shows how to open the speaker.