The message is the result of a safety mechanism we added in the V14.1.0.81 firmware version for the battery.
The function is to stop charging the battery when the battery temperature is too high.
The notice message will pop up, and you can press the return key (GV50) / OK key (GV31) to close the message. You can then continue to use the projector as is. The projector will still function normally and be powered by the power cable. It will only stop battery charging.
After the battery temperature goes down to a normal range, it will begin charging again.
If the message pops up very often or cannot be closed, please contact BenQ Support for further assistance.