Except for Cisco Desk Phone 9841, which has a USB-A port, the other models in Cisco Desk Phone 9800 Series are equipped with both a USB-A port and a USB-C port. See Get started with Cisco Desk Phone 9800 Series to locate the ports.

The power output specifications on the phone vary from port types and power sources. See the following table for the specifications.

Table 1. Power output specifications
Phone modelUSB portPower output
Power over Ethernet (PoE)Wall socket power

9841

USB-A

0.25A at 5V (1.25W)

0.5A at 5V (2.5W)

9851

USB-A

0.5A at 5V (2.5W)

1A at 5V (5W)

USB-C

0.5A at 5V (2.5W)

0.5A at 5V (2.5W)

USB-A on KEM

0.15A at 5V (0.75W)

0.5A at 5V (2.5W)

9861/9871

USB-A

0.5A at 5V (2.5W)

1.3A at 5V (6.5W)

USB-C

0.5A at 5V (2.5W)

0.5A at 5V (2.5W)

USB-A on KEM 1

0.15A at 5V (0.75W)

1A at 5V (5W)

USB-A on KEM 2N/A

0.5A at 5V (2.5W)

USB-A on KEM 3N/A

0.15A at 5V (0.75W)

If a connected device attempts to draw more power than the USB port's maximum output, a warning message will pop up, prompting you to unplug the device. When you see the message, disconnect the device to protect your phone.

Best practices for device charging

  • Only charge devices with a rated input power that doesn't exceed the phone's maximum output power.
  • When using a USB cable to connect Cisco Headset 700 Series or Bang & Olufsen Cisco 980 to the USB-A port on the phone or on the attached KEM, follow any of these practices to avoid overcurrent problems:
    • Connect the headset to the phone via the USB HD Adapter.
    • Fully charge the headset before connecting it to the phone or the attached KEM with a USB cable.
    • Connect your phone to a power socket, as the USB port over PoE provides less power.
  • Avoid forcefully inserting plugs into the USB ports and ensure they match correctly.
  • Never cover charging devices to prevent overheating.
  • Unplug the device if it's already fully charged.