I have tried 5 different 12 cell batteries from secondary companies in my Toshiba Satellite L775D running Windows 7 Home premium. The laptop came with a 6 cell that works perfectly. The same thing occurrs when putting the 12 cell batteries in my laptop. When having the AC power plugged in the laptop does not recognize the battery. I then do a restart and the battery icon shows the new battery at 100% charge. However when I disconnect the AC the laptop immediately goes dead and will not restart until I remove the battery. Any ideas ?