The Nitecore Digicharger D4 is my go to charger for my Eneloop and 18650 rechargeable batteries. It delivers a decent battery current and can do one to four cells, simultaneously. It's open top design allows batteries to be inserted and removed quickly, but overtime, allows the inside to collect dust. My cover design, when regularly used, significantly reduces dust from accumulating inside the battery compartment.
The cover can be used on the battery charger with batteries inserted or not. The cover also allows heat ventilation for charging batteries. The plastic filament to use for the 3D print is unimportant.
My print is made in 1.75mm Bambu PLA-CF filament, with 0.2mm layer height and 15% infill on a Bambu X1 Carbon printer. Print supports are not required.
I hope that you can find this print useful, too.
Remember to leave me some feedback or even a tip to keep me enthused to make more of these drawings.
For my latest models, see my main uploads site: https://makerworld.com/en/u/3687936443