With the Lenovo T440s, there is a known battery issue.
The issue can in 8/10 cases be resolved with the solution below.
1. Turn off the machine.
2. Unplug the machine from any power source.
3. Take out the External battery.
4. Press and hold for 10 seconds, the emergency reset hole (this needs to be done with a paperclip)
It is number 5 in the picture below.
5. Plug in the power again (NOT THE BATTERY)
6. Turn on the PC.
If the solution doesn't work, please create an RMA on following site: https://tier1asset.com/rma-application-form/