I have a new XPS 13 9310 which is connected to the power adapter pretty much all the time.

As such I've configured the Custom option in the Dell Power Manager utility to 50% and 80% for the start and stop levels respectively.

This simply isn't working.  What I'm seeing is the laptop sitting at about 82/83% charge.  Whilst it's not charging constantly, every few minutes the light on the front flashes once or twice and the system tray icon animates as it briefly charges and then stops.

It appears that it's constantly topping up the battery so it stays around the 82/83% level rather than doing what it should and allowing it to slowly discharge to 50% before charging back to 80%.

Please advise as I'm very concerned this behaviour will harm the life of my battery.