Triflex charging state indicator:

The battery charging state is displayed on the front of the PowerUnit.
Duoflex charging state indicator:

The battery charging state is displayed on the top of the PowerUnit.
Battery charging state indicator (while charging):
Duoflex HX1:
Lowest capacity: left indicator flashes.
Increasing charging capacity: left indicator lights up; middle indicator flashes.
Further increase in charging capacity: left and middle indicators light up; right indicator flashes.
Charging capacity approx. 91–99%: Left, middle, and right indicators light up.
100%: Indicator switches off.
Battery charging state indicator (while in use):
Triflex HX2:
100–70%: Top, middle, and bottom lights are lit up.
69–35%: Middle and bottom lights are lit up.
34–11%: Bottom light is lit up.
10–0%: Bottom light flashes slowly.
Duoflex HX1:
Maximum charging capacity: All indicators light up.
Decreasing charging capacity: Two indicators light up.
Charging capacity decreasing further: One indicator lights up.
Minimum charging capacity: One indicator flashes.