Had a spare few minutes to work on this concept a bit more.
Drill system flashlights are a relatively inexpensive way to make a base to use the batteries. We happened to have a older Dewalt here that we had experimented with before.
So some drilling, soldering and Jbweld epoxy later we have a more compact and useful unit. Home depot has a good selection of flashlights from others. We just have a lot of Dewalt batteries.