S1 manufacture date
 

Then you are lucky. Mine says it was built the same day and it definitely has the problem.

It would be fun to know exactly what the issue is, but I suppose we'll never know.

_RP

How did you test? Charge it fully and leave it for a week? It should stay at 100% but will drop to 80% or less, is that correct?

Basically, yes. How I tested:

Charge up the the S1 for several hours until fully charged.

Turn on the S1 and unplug the power cord from the S1.
Connect to the now fully charged S1via the Bose Connect app from your phone or tablet.
Notice the the little circle in the lower right (I used the iOS version). It should say "100".
Good.

Turn the S1 off. Leave the power cord unplugged.

Wait 24 hours. Turn on the S1, connect to your S1 via again the Bose connect app.
Look at the little circle again. Is the number less than 100? Mine would say "90".
If less than 100 notice that part of the little circle is gone. Make mental note of how
much is gone.

Turn the S1 off. Power cord still unplugged.

Wait another 24 hours. Turn S1 on and check the little circle again with the Bose Connect app.
Is it the same as the day before or has more disappeared?
For me more it would be more gone and the number would be "80".

Turn the S1 off. Power cord still unplugged.

Wait yet another day and check again. If the Connect app still says 100 I'd say
you do not have the problem. If it's anything less than 100 I'd call Bose Tech
Support and ask them.

BTW, I'm pretty sure the Bose Connect app only resolves the circle number to
multiples of 10, you know, the granularity of the rounding in the Connect app.
That's why it's best to test over a few days if you can.

If you want more help and/or details about checking this let me know. Hope
this helps clarify. Cheers!

_Roger

So last night I got the Bose ap. It found my unit instantly and my charge was 90%. This was after nearly 3 full days unplugged, and I played guitar and sang through it yesterday morning (SM57 for guitar and SM58 for vocals) for at least 30 minutes before going to work. I also played some music through it last night Bluetoothed through my iPhone.

This morning it's at 90% still. It was built August 2018.

Sounds like you do not have the problem. That’s good.
Seems to be in units manufactured early on.

Cheers, _RP

I have so many issues with lithium batteries not holding a charge lately.

Did you buy your S1 Pro before about Sept. 2018? You may have this issue.
 

My replacement showed up in 3 days. I think there’s a Bose warehouse an hour south of me.

I plugged mine in last weekend. It charged to full. I unplugged it and played for a few minutes Monday morning, turned it off and left for a business trip. Came home on Friday and it was dead.

I will call Bose. Thanks guys.

I received the replacement S1 Pro today - second day air: shipped on Friday, received today. Kudos to Bose for making this so easy. I put the old one in the box the new one came in, taped it up, took it to the UPS Store, they scanned the info from my phone... done.

I tested all three channels and will have it plugged in this evening, then see how the charging holds up.

I really appreciate how capable this small unit is. No, it won't replace a full PA with FOH speakers/horns and monitors when you need that kind of power. But, it works great for my use. And a line out to a bigger PA is easy, with the S1 as a monitor.