Replacement battery bay for miniature single-board quad copter

This battery bay attaches directly to the X-shape single electronics-board mini quad copters and can replace the entire plastic upper cover.

One of the quad copters it will fit to is this one: http://www.xheli.com/28h-u207-quad-light.html

Removing the top (which will also make the existing battery bay detach) and replacing it with just a battery bay reducing the weight. After this modification the achievable height and speed of ascent hugely improved, going full power up on a freshly charg