I am running Ubuntu 18.04.4 LTS x86_64 on a Lenovo Thinkpad T440p. The laptop only runs for about 20 minutes on battery power. In the process of troubleshooting this issue, I have installed tlp and powertop. The output of tlp-stat tipped me off to the fact that the upower daemon is reporting "energy_full" as being greater than "energy_full_design." This is confirmed by running "systemctl status upower" - I get the following:
"Jul 06 23:21:06 cannon upowerd: energy_full (71.280000) is greater than energy_full_design (47.520000)"
Apparently this is a known bug (see below links) that causes the battery percentage to be inaccurately reported to the OS, causing a premature suspend, but I can't seem to find a fix.
I have stopped and started the upower daemon, and rebooted the machine to no effect.
Any help is greatly appreciated. This bug effectively makes my laptop a desktop.