How do I know when my go cube is fully charged?

Excuse me, could you please clarify how one can determine if their go cube has achieved a full charge? I'm new to this and I'm not quite sure what indicators to look for to ensure that my device is ready for use. Is there a specific light that turns on or a notification that appears on the screen to signal a full charge? Additionally, how long does it typically take for a go cube to fully charge? I'd appreciate any guidance you can provide.