This is a single piece Peak for the Halo Helmet Full Size A ( http://www.thingiverse.com/thing:158120 ) that has additional mounts for 9V Batteries.
Only one battery is required for present LEDs but you never know.
Printed nicely and batteries "snick" in.
Though note that this will hold a Duracell nicely, but some other no-names are slightly smaller.
Added split left and right peaks for smaller beds.