Acer HS244HQ - Manual (Page 21)

EN-20
Battery indicator
•
The 3D glasses have power for up to 70 hours of continuous use. Near the
end of the battery life, the indicator LED will flash 4 times consecutively
every 1 minute and till the battery life is ended. When you turn on with
low power, LED will be light up for 5 second, then the 3D glasses will
shut down.
Battery replacement
•
Make sure the positive terminals face outwards.
Changing the nosepiece
•
3D glasses come with three interchangeable nosepieces to give you a
comfortable fit. You should pull out the current nosepiece horizontally
and insert the one that fits you best.