Dell Latitude 3540 Owner's Manual

If the computer is connected to an electrical outlet, the battery light operates as follows:

• Alternately blinking amber light and white light — An unauthenticated or unsupported non-Dell AC adapter is attached to your laptop.
• Alternately blinking amber light with steady white light — Temporary battery failure with AC adapter present.
• Constantly blinking amber light — Fatal battery failure with AC adapter present.
• Light off — Battery in full charge mode with AC adapter present.
• White light on — Battery in charge mode with AC adapter present.