Dicuplik langsung dari website AT&T:

Panduan indikasi Baterai Sierra 875U/881U

Goal:
What do the LED lights indicate on the AT&T USBConnect 881

Change:
Informational Only | Limited Support: This solution is intended for informational purposes only. AT&T provides network, billing, and provisioning support for the wireless voice and data networks. Additional support beyond this solution must be directed to Sierra Wireless at http://www.sierrawireless.com/ or your internal IT department.

Fix:

B. How do I charge the battery for the AirCard USB modem?

Follow these directions to charge the battery for the AirCard USB modem:

1. Ensure the battery is inserted into the AirCard USB modem.

2. Insert the AirCard USB modem into your computer’s USB slot. It will automatically begin charging. * You can also attach the docking station* to your computer’s USB slot and insert the AirCard USB modem into the docking station.

3. Charge the battery until the PWR LED is green. (This should take less than 3 hours.) *The availability of the docking station depends on your service provider. Note: After the initial charge, your AirCard USB modem will charge the battery anytime it is connected to the USB port and it is not transmitting data.