![background image](http://html1.mh-extra.com/html/sennheiser/cx-400bt-series/cx-400bt-series_instruction-manual_1240282026.webp)
Using the earphones
26 | CX 400BT True Wireless
LED
Charging case WITH
earbuds inserted
Charging case
WITHOUT earbuds
inserted
lights up
green
... earbuds are fully
charged and the
charging case can
still charge at least
one complete cycle
... charging case is
fully charged
pulses
yellow
... earbuds are being
charged via the
rechargeable bat-
tery of the charging
case
–
lights up
yellow
... earbuds are fully
charged, the
charging case
cannot charge
another complete
cycle
... charging case is
charged less than
90 %
lights up
red
... rechargeable bat-
teries of the earbuds
and the charging
case are empty
... rechargeable bat-
tery of the charging
case is empty
flashes
red
... a charging error/
battery error has
been detected in at
least one earbud (>
30)
... a charging error/
battery error has
been detected in the
charging case (> 30)