I just purchased a Toshiba Satellite C55-b5300 and after resetting the rtc time removed the battery to install more memory only to find that on startup the boot required the rtc clock to be reset. I went back and disassembled the bottom to find the CMOS battery and there was NONE! So what's that all about? Is there any way to install a battery or do I have to rely on the system battery? It appears Toshiba for some unknown reason decided not to install a battery into this model. Is this so or have I purchased a defective laptop computer?