The Nebula Mars 3 projector comes with USB-C and USB-A ports that support charging for external devices. Here's how you can use them:

1. While the projector is turned on, connect your device to the projector via a cable to start charging automatically.

2. If the projector is turned off, press and hold the "Mode" button until your connected device starts charging.

3. To stop charging, hold the "Mode" button again.

Note: The charging speed may vary depending on the device and cable used. It is recommended to use the original cable that came with your device for optimal charging performance.

If you have any questions, please contact us for further assistance.