Battery Run-Down Protection; Accessory Power Outlet(S) - Chevrolet 2009 Suburban Owner's Manual

The battery can be discharged at idle if the electrical
loads are very high. This is true for all vehicles. This is
because the generator (alternator) may not be spinning
fast enough at idle to produce all the power that is
needed for very high electrical loads.
A high electrical load occurs when several of the
following are on, such as: headlamps, high beams, fog
lamps, rear window defogger, climate control fan at
high speed, heated seats, engine cooling fans, trailer
loads, and loads plugged into accessory power outlets.
EPM works to prevent excessive discharge of the
battery. It does this by balancing the generator's output
and the vehicle's electrical needs. It can increase
engine idle speed to generate more power, whenever
needed. It can temporarily reduce the power demands of
some accessories.
Normally, these actions occur in steps or levels, without
being noticeable. In rare cases at the highest levels of
corrective action, this action may be noticeable to the
driver. If so, a Driver Information Center (DIC) message
might be displayed, such as BATTERY SAVER ACTIVE,
BATTERY VOLTAGE LOW, or LOW BATTERY. If this
message is displayed, it is recommended that the driver
reduce the electrical loads as much as possible. See DIC
Warnings and Messages on page 3-64.
3-20

Battery Run-Down Protection

This feature shuts off the dome, and reading lamps
if they are left on for more than 10 minutes when
the ignition is off. This will keep the battery from
running down.

Accessory Power Outlet(s)

Accessory power outlets can be used to connect
auxiliary electrical equipment, such as a cellular
telephone.
There are two under the climate controls, one inside the
center floor console, one on the rear of the center
floor console and one accessory power outlet in the rear
cargo area on the passenger side.
To use an accessory power outlet, remove the protective
cap. When not in use, always cover the accessory
power outlet with the protective cap.
The accessory power outlets are powered, even with
the ignition off. Continuing to use accessory power
outlets while the ignition is in LOCK/OFF may cause the
vehicle's battery to run down.
Notice: If electrical devices are left plugged into a
power outlet, the battery may drain causing the
vehicle not to start or damage to the battery. This
would not be covered by the warranty. Always unplug
all electrical devices when turning off the vehicle.