I am going to be traveling soon so I wanted a case that would meet the TSA requirement that all batteries had to be isolate from each other so that the contacts can not touch each other, or other batteries. I designed this case to fit that bill. Can double as general transport and storage for the eflite batteries.
Update: I have recently returned from a trip out of country where I used this case. I got through TSA as well as the foreign countries security on the way back without issue. Also of note, I printed out the official lipo travel rules. I can not guarantee what your experiences with TSA will be, use this at your own risk. I will say if you do the research and know the rules and can answer questions correctly and with authority when asked things go a lot smoother.
As for the print itself, The lid slides on pretty well and its pretty snug, you may need to sand it to get a good fit. You also might need to sand down the locking nub, by default it held a little too aggressive with my print but quickly solved by sanding it down a little. I printed mine at 20% infill and support, however with the fillets that I used, it may actually print well without support. If you print it, let me know what settings you used and what results you got. Share some pictures and your feedback.
Update 1/27/17: I added a new version "Holder_WhoopExtended.STL" which is extended in length and has larger relief pockets for the larger "PowerWhoop" PH2.0 connector. This is the photo using the Blue PETG filament in my photos. The batteries shown are 250mAh "HV" cells. The lid is compatible with both version.