issues for my letv 1s help plz

Hi; i have installed the official rom of my letv 1s x500 successfully, but when the phone suddently reboot and come to 1% of battery life, i’ve tried to charge it, but it turned off, but not really turned off because the notification led still in red colour, but the screen is black, i tried to turn it on with no result, i don’t know how to resolve this issue. please help me.
i notice, that before installing the official rom, my phone was rooted, and when i tried to install rom with your method, the TWRP start not the start button, but i have maked a success rom installation.
now i can’t use my phone, please help me to find a solution. thank you.
(sorry my english is poor)