This week on project farm, Todd tests DeWALT PowerStack, DeWALT 2.0 AH, DeWALT 5.0 AH batteries in a head to head comparison. Battery performance is compared using an impact driver, hammer drill, reciprocating saw, and air blower. Cold temperature performance is tested after batteries are chilled to below freezing temperature for over 12 hours. Batteries also tested for amp hour capacity. Finally, the PowerStack battery is dismantled to look at the build construction.