Mag-Lite 3-Cell C Size Adapter for 18650 Lithium Batteries

For this adapter, you will need to be able to machine the front and rear spacers from aluminum or brass. The dimensions are given in the drawing.

The three (3) C cell alkaline batteries are replaced by two (2) 18650, button top, lithium batteries. I have used the unprotected type. The two 18650 batteries provide 7.4 volts compared to 4.5 volts from three C cell alkaline batteries, essentially converting the 3 cell flashlight into a 5 cell flashlight equivalent. I will use a LED Mag-Lite conve