Found the following on Engadget. My guess they will not be releasing any more frames. I have two pairs and both are now gathering dust. Got tired of having to charge them all the time and the last time I wore the 2nd gen frames, it only got two hours before charging. I did not get the third generation because of all the changes they made.
I now wear Lucyd and they last well over ten hours before needing charging. Since it has the ability to listen to one arm at a time, it should last all day. Now, if Amazon Echo Frames lasted that long, I am pretty sure their sales would skyrocket.
The Echo Frames have turned out to be a pretty big misfire for Amazon. The same report indicates that the company has sold only 10,000 units since the third-gen glasses came out last year.
https://www.engadget.com/big-tech/amazon-reportedly-wants-drivers-to-wear-ar-glasses-for-improved-efficiency-until-robots-can-take-over-174910167.html