my G74SX Shuts down when it reaches 20%, or 28% on battery. is this normal? or is my battery dead? please help me!!

Catalyst Mobility v10.12 CCC2 Preview Win7 64bit is the orginal ATI Catalyst v10.12 mobile driver modded only to full support the new Catalyst Control center 2 Beta for laptop. this driver support only Win7 64bit or Vista 64. tried with ASUS G73JH. D...