Yes, using battery mode may impact image brightness. The GV50 features three brightness modes: Auto, Eco, and Custom.
Auto Mode: The projector detects the power supply voltage and adjusts the screen brightness accordingly. Brightness can be reduced by selecting Eco or Custom modes.
With Supplied Adapter: The screen's peak brightness reaches 100%.
With Built-in Battery:
General brightness is 70%.
If battery power is less than 20%, the peak brightness reduces to 20%.
With Power Bank via USB-C:
For power banks supplying between 45W (20V2.25A) and 65W (20V3.25A), the peak brightness is 20%.
For power banks supplying more than 65W (20V3.25A), the peak brightness is 100%.
The maximum battery life of 2.5 hours is measured under Eco mode, specifically while streaming content from YouTube.