I was stuck in the woods with no jumper cables. Some kind young person had left the dome light on overnight. I had an 18v dewalt, 4' of romex, and a cheap voltmeter. I used the voltmeter to determine the prong polarity on the dewalt battery (more central prong is +), bent a loop in the ends of the romex and jammmed them in the battery prong cavity with some removed romex insulation in there to prevent shorts, jammed the other end of the romex in the gaps in the battery post connectors, and it cranked right up. I love dewalts. The recip saw is great on forest service gate locks that they lock you in with without checking the roads first...