The original is https://www.thingiverse.com/thing:2144462

as crt404 suggested in his... "I slide the battery in from the front, rather than push it past the retaining lugs. Angle of the lugs allows it to be printed without support."

I also made it slightly smaller to fit the battery nice and snug. Before it was quite loose and would shake around inside the holder. The retaining lugs pretty much secure it in so if upside down, the battery won't fall out.

I also made the walls solid as I figured it would help with a nicer print without so many retractions.