Please see this thread:

And again. Not the answer. Since that is in the Sonos app and it's not showing the percentage at all. So my question still remains and that thread is not helping.

I see. My apologies for misunderstanding the question. I was confused by your initial statement about not seeing the battery while on Bluetooth, when in fact your issue is about not seeing battery information in the Sonos controller. 

So in order to provide Sonos additional hard data to look at, in order to investigate this issue, I would recommend that you submit a system diagnostic, and call Sonos Support to discuss it, or post the diagnostic number here for a Community Moderator to pick up.

There may be information included in the diagnostic that will help Sonos pinpoint the issue in the current Sonos controller, and help you find a solution.

When you speak directly to the phone folks, there are more options available beyond just the diagnostic analysis.