Personal Protective Equipment and Self-Contained Breathing Apparatus No. 1 Questions taken from Jones & Bartlett Fundamentals of Fire Fighter Skills (3rd Edition) Progress Indicator: Question 2 of 23 2.  The level of charge/status of the PDM battery is indicated by ___________. Choices: an LED light located on the front of the charging unit the internal clock in the unit the sound of the charger the battery graphic display screen