Just to follow up, I ended up purchasing an “always on” 10K mAh power bank made by Iniu (Model B41). It charges up my Costco KS10s, but once they’re charged up, for some reason the hearing aids begin discharging. So if I leave them in overnight, I awaken to aids at about 50%. If I leave them in for 2-3 hours then unplug the charger, they’re fully charged. The power bank works on my other devices just fine.
Thanks for your help with my question.