Dell Latitude E6540 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.