After using several of these AA Li-ion batteries for some time, we needed a way to store them sensibly. At the same time, it should be possible to charge the batteries in the intended holder, among other things to prevent short circuits caused by dangling.
After several revisions, we now have a number of holders in use, printed in gray PLA with green or black sliders (to indicate the charge status, black because I didn’t have any red available):



Downloads
Here are the STL files needed for printing:

