Ver 1 Strong wall design great to keep batteries from shorting out or crushed, will also protect them from normal drops and hits.

Ver 2 Everything that Ver 1 will do but it allows for TPU printed inserts that further absorb shocks and vibrations. It greatly increases protection for the batteries.

Ver 2.1 Lid now has tabs on the side instead of solid wall to help shorten break in time. The lid will still be snug how ever this does decrease the amount of the break in as well as make it easier to use

I have a Canon remote Speedlite and the thing eats batteries like crazy so I keep an extra set of rechargeable AA batteries in my camera bag. I wanted a case to keep them from shorting out as well as keep them safe from drops as I have clumsy hands. Plus high capacity rechargeable batteries are more expensive as is the equipment they're going in so I want to keep the chances of them leaking / exploding as low as possible and that starts with taking good care of them by not busting them up from drops. The case has wide walls the whole way around the batteries including the top and bottom. The battery well and the case outer wall is a minimum 5.5mm apart, the case would have to be completely destroyed for the batteries to take a direct hit. Be sure to limit Infill to no more than 20% 'Grid' style as the honeycomb effect will help absorb very hard impacts.
If you print this and have the time, please upload a pic to the "I Made One" tab. I love seeing my designs get printed :) Thanks!