I installed Ubuntu 13.04 on my X1 Carbon Touch laptop yesterday and everything worked fine, the battery charged as usual. Today I've noticed that the battery indicator shows me that I am working on battery power even if I plug power adapter into AC and LED on the left side of the laptop (near the power connector) is green.
I tried to use tpl tools as described somewhere on this site to set start and stop discharge thresholds but it does not help.
The only way to charge the battery is to shutdown laptop completely (not suspend) and wait for a couple hours. Which is not so great though. :)