I disassembled the saw and traced the wiring to figure out which terminal was positive and which was negative. Once I determined which was which, I ran some wire from the DeWalt battery to the saw terminals to make sure that it operated. It did. Now to make it usable.
Step 1: Materials
DeWalt 18v Battery
4 - female disconnect crimp-on connectors (16 AWG)
1 - 5 inch length electrical wire (16 AWG)
1 - zip-tie