Why is there only two battery bars displaying on my battery indicator when fully charged?

The latest software has two bars to indicate battery level. The top bar (blue) and the bottom bar (red)

This is to provide a more accurate reading of the batteries level.

Lithium batteries do not behave in the same manner as SLA batteries.

SLA batteries will give an accurate reading using the four bar system when a lithium battery gives a more accurate reading using a two bar system.

The two bars are illuminated whilst the battery has between 25% and 100% capacity.

When the capacity drops to 25% then the bottom red bar is only illuminated.  You will have roughly 30 minutes of play left.