Some power considerations for Zoom’s Cat M1 / NB1 USB cell modems

Zoom’s Cat M1 / NB1 cell modems use Quectel BG96 modules. In some modes, these modules consume more than 500 mA, as discussed below. Very little current is consumed in the other circuitry in the modem. Zoom’s cell modems handle power and current very capably, so you shouldn’t have any problems if you pay attention to the notes below.

1. The ability to supply current from a USB port to a device such as a USB cell modem varies by the current-sourcing USB port. Typically, a USB port can source at least 500 mA, but often it can source more. If your modem is not receiving enough power, the modem could shut down and might have problems restarting.
2. 2. Zoom’s Cat M1 / NB1 USB cell modems require up to 600 mA average current when operating in some 2G modes. In Cat M1 or Cat NB1 mode, the device will not draw more than 240 mA. When a device can't source more than 500 mA of current there are 2 main alternatives:
   1. Turn off 2G mode. To turn off 2G mode enter the following command:
      AT+QCFG: "nwscanmode",3
      This command is stored in the modem's non-volatile memory.
   2. Use the modem's micro-USB supplemental power port to supply more current from another USB port of the current-sourcing device, or from a 5V supply output of the device such as a 5V power cube. Note that in some cases a second USB port on the power-sourcing device uses the same power supply as the first USB port, so in that case the second USB port on the device may not be useful