Forbes Kay apparently the T450 has some issues with the CMOS etc. For some a quick fix that seems to work is to reset the CMOS. Just disconnect it from the motherboard, wait a couple seconds, then plug it back in. Check to see that if you remove your external battery and disconnect the internal battery that your laptop functions normally with the AC power supply adapter. Download the hardware maintenance manual [https://download.lenovo.com/pccbbs/mobiles_pdf/t450_hmm_en_sp40a27225.pdf|from here] and check page 48 etc.