Mark I Mod I.... I'm done... cut a section of small bicycle inner tube 2 3/4"... insert 3 Eneloop AAs.... center in tubing, there should be about 3/8" over at each end... insert a quarter (heads out for + and tails for -)at each end to act as terminals...they are held in place by the excess bike tube.... to insure better contact at the (-) end, fold a piece of aluminum foil several times... insert between the flat ends of the cells and the quarter as they don't make as good of a connection as the positive end... you may need to add a couple of pennies (pre 1982 are copper) to the positive end to make a connection...or trim to fit... will fit in a D sized flashlight tube