Helmet Patch

Removed the old battery pack from back of helmet and covered with a white plastic plate.
The battery pack was pushing against the back of my head. 
By doing this I gain about 3/8 of an inch more room inside helmet for my fat head with foam padding.

Helmet Fan

During the Charticon convention I had minor complications with breathing under the mask and the eye lenses fogging up.
After watching some YouTube videos and reading forum searches, I got a few ideas to install a small cooling fan inside of the helmet.
Found a perfect mini-fan and 9volt battery connectors at Radio Shack. 
The helmet I used originally came with a on/off switch, that still works and would fit on back of helmet.
I drilled vent holes on top of helmet ridge cap for air intake, and a hole below the fan for airflow into helmet.
 

 During installing of switch, I had to re-glue a plastic piece that came separated.