With 10 Cortexes and 10 VEX IQ brains being put to use by our As our 60+ 4-H club members build, program, and test their VRC and VEX IQ robots, , batteries and chargers are in constant demand. When treated well, the standard VEX batteries hold up well, but we routinely abuse our batteries.  Replacing … More Alternative Batteries for the VEX Cortex and VEX IQ Brain