i found these at hd and tryed them
cut wired and put in a switch to turn them on and off
using 2 overhead they are fine to read by
and they say will last 8 to 10 hours on a full day charge
just mount cell on top behind your vent
and have unlimeted lights
just an idea to play with
Model LZ413A
http://www.homedepot.com/prel80/HDUS/EN ... 0&MID=9876