IFJ_01-2020_FWEVX Ken Norberg February 25, 2020 13 Views The FW-EVX is based around an innovative carbon fiber chassis with each lithium-ion battery cell wrapped in carbon fiber boxes using patented 223 technology, creating a lightweight, crash-resistant and scalable structure. Photo courtesy of Williams Advanced Engineering The FW-EVX is based around an innovative carbon fiber chassis with each lithium-ion battery cell wrapped in carbon fiber boxes using patented 223 technology, creating a lightweight, crash-resistant and scalable structure.