5-10
12 V Starting and Charging
Electrical Power Management
Description and Operation (Gasoline)
The electrical power management is used to monitor
and control the charging system and alert the driver of
possible problems within the charging system. The
electrical power management system makes the most
efficient use of the generator output, improves the
battery state
‐
of
‐
charge, extends battery life, and
manages system electrical loads.
The load shed operation is a means of reducing
electrical loads during a low voltage or low battery
state
‐
of
‐
charge condition.
The idle boost operation is a means of improving
generator performance during a low voltage or low
battery state
‐
of
‐
charge condition.
Each electrical power management function, either idle
boost or load shed, is discrete. No two functions are
active at the same time. Idle boost is activated in
incremental steps, idle boost 1 must be active before
idle boost 2 can be active. The criteria used by the body
control module (BCM) to regulate electrical power
management are outlined below:
Function
Battery Temperature
Calculation
Battery Voltage
Calculation
Amp-Hour
Calculation
Action Taken
Idle Boost 1 Start
Less Than
−
15°C (5°F)
Less Than 13 V
—
First level Idle boost
requested
Idle Boost 1 Start
—
—
Battery has a net loss
greater than 0.6 AH
First level Idle boost
requested
Idle Boost 1 Start
—
Less Than 10.9 V
—
First level Idle boost
requested
Idle Boost 1 End
Greater Than
−
15°C (5°F)
Greater Than
−
12 V
Battery has a net loss
less than 0.2 AH
First level Idle boost
request cancelled
Load Shed 1 Start
—
—
Battery has a net loss
of 4 AH
Rear Defrost, Heated
Mirrors, Heated Seats
cycled OFF for 20% of
their cycle
Load Shed 1 Start
—
Less Than 10.9 V
—
Rear Defrost, Heated
Mirrors, Heated Seats
cycled OFF for 20% of
their cycle
Load Shed 1 End
—
Greater Than 12 V
Battery has a net loss
of less than 2 AH
Clear Load Shed 1
Idle Boost 2 Start
—
—
Battery has a net loss
greater than 1.6 AH
Second level Idle boost
requested
Idle Boost 2 Start
—
Less Than 10.9 V
—
Second level Idle boost
requested
Idle Boost 2 End
—
Greater Than 12 V
Battery has a net loss
less than 0.8 AH
Second level Idle boost
request cancelled
Idle Boost 3 Start
—
—
Battery has a net loss
of 10.0 AH
Third level Idle boost
requested
Idle Boost 3 Start
—
Less Than 10.9 V
—
Third level Idle boost
requested
Idle Boost 3 End
—
Greater Than 12 V
Battery has a net loss
of less than 6.0 AH
Third level Idle boost
request cancelled
Load Shed 2 Start
—
Less Than 10.9 V
Battery has a net loss
greater than 12 AH
Rear Defrost, Heated
Mirrors, Heated Seats
cycled OFF for 50% of
their cycle. The
BATTERY SAVER
ACTIVE message will
be displayed on
the DIC
Load Shed 2 Start
—
Less Than 10.9 V
—
Rear Defrost, Heated
Mirrors, Heated Seats
cycled OFF for 50% of
their cycle. The
BATTERY SAVER
ACTIVE message will
be displayed on
the DIC
2021 - Silverado 4500HD, 5500HD, and 6500HD Electrical Body Builder Manual
