How to remove battery from thinkpad x1 carbon

Hallo! I need help! Lenovo  thinkpad x1 carbon. I can not turn it on. After I remove the battery and disconnect the internal battery and then reconnect, it starts. I turn off. Starts. I turn it off, after one hour, it won't turn on again. I reconnect and connact both batteries, and it works. The internal battery is new. What could be the problem?

Update bios to newest version and test once again.