These are side lids for Li-Ion Packs, based on 18650 cells. One version is for 4S packs, one for 6S.
This design consists of several parts.
You surely need some sort of tape or heat shrink tubing to finalize the battery back.
Easy printing as oriented without supports or rafts.You may use 0.2mm resolution for a nicer look.
May work with non-flexible filament. If the lid is too tight, try scaling it up for 0.45% or 0.5%.
Feel free to change my designs on Tinkercad but respect the licence.
The author hasn't provided the model origin yet.