Power and Runtime

The ADOS Ground Agent is designed to stay compact. It does not need an internal battery to work in the field. Power it from USB-C using a wall adapter, a USB-C PD power bank, a vehicle adapter, or another regulated field power source. This keeps the ground node small and lets you choose the runtime you need for each job.

Recommended power sources

Source	Use it for	Notes
USB-C wall adapter	Bench work, lab testing, fixed setup	Use a supply that can sustain the board’s required output under load.
USB-C PD power bank	Field operation	Best portable option. Pick a bank with sustained output, not only a high peak rating.
Vehicle or field battery adapter	Long sessions	Use only regulated USB-C output. Avoid bare battery leads into the board.
Laptop USB-C power	Short setup only	Some laptops limit current. Use separate power when video, WiFi AP, HDMI, or extra radios are active.

Do not judge power banks only by the mAh label. Most banks print mAh at internal cell voltage, not at USB output. Runtime should be estimated in watt-hours.

Expected draw

Use these bands for planning:

Ground Agent mode	Expected draw	Plan for
Direct/headless node	~7.5 W	One radio, no HDMI kiosk, normal local clients
Kiosk or dual-radio node	~9-11 W	HDMI, browser kiosk, extra radio, or heavier uplink use
Supply ceiling	15 W	Power-supply sizing and brownout margin, not normal runtime

The ceiling matters because weak supplies can reset USB radios during spikes. It is not the number to use for average runtime unless you want a worst-case estimate.

Runtime estimates

These estimates assume 75-85% usable energy after USB conversion losses.

Power bank label	Usable energy	~7.5 W direct/headless	~10 W kiosk/dual-radio	15 W ceiling
10,000 mAh	~28-31 Wh	~3.7-4.1 h	~2.8-3.1 h	~1.9-2.1 h
20,000 mAh	~56-63 Wh	~7.5-8.4 h	~5.6-6.3 h	~3.7-4.2 h
30,000 mAh	~83-94 Wh	~11.1-12.5 h	~8.3-9.4 h	~5.5-6.3 h
99 Wh PD bank	~74-84 Wh	~9.9-11.2 h	~7.4-8.4 h	~5.0-5.6 h

Old banks, thin cables, hot weather, and extra devices powered from the same bank reduce runtime.

USB tether power

USB tether is a data path first. A laptop may also power the Ground Agent, but that is not the recommended field setup. For reliable USB tether:

Power the Ground Agent from a wall adapter or USB-C power bank.
Use a separate USB-C cable that is explicitly data-capable.
Treat laptop back-power as a short setup convenience only.
If video freezes or the USB network drops under load, test again with a known-good power source before changing radio settings.

Brownout symptoms

Power problems often look like radio or network problems:

Symptom	Likely cause	First fix
USB tether appears and disappears	Host power limit or bad cable	Use separate power and a known data cable
Video freezes when more clients join	Supply sag under WiFi load	Use a stronger USB-C source
Radio adapter disappears from diagnostics	Brownout on the USB bus	Change power source and cable
HDMI kiosk works, then drops video	Load spike from display and browser	Use a higher-output USB-C source
Works on wall power but not on a power bank	Bank cannot sustain output	Use a PD bank with sustained output rating

Field checklist

Use a USB-C source that can sustain the required output.
Carry one known-good data cable and one known-good power cable.
Keep the power bank out of direct sun when possible.
Start long sessions with the bank fully charged.
For USB tether, separate power from data whenever the hardware allows it.

What is next

USB Tether for wired laptop setup
Supported Hardware for board and accessory requirements
Troubleshooting for power-related symptoms

​Power and Runtime

​Recommended power sources

​Expected draw

​Runtime estimates

​USB tether power

​Brownout symptoms

​Field checklist

​What is next

Power and Runtime

Recommended power sources

Expected draw

Runtime estimates

USB tether power

Brownout symptoms

Field checklist

What is next