!!
critical Logitech
Error Code RED_LED_15X
Battery level is critically low, with scroll wheel blinking red continuously or rapidly. Implies less than 15% battery left.
? What Causes This
Battery drained completely and has not been recharged soon enough.
✓ How to Fix It
Plug mouse into PC immediately to charge it fully again before use.
Source: page 50 of the official manual
From the manual
This error code appears in:
Logitech G703 Lightspeed Wireless Gaming Mouse