Hummer H3. Manual — part 9

BATTERY COMMON CAUSES OF FAILURE

A battery is not designed to last forever. With proper care, however, the battery will provide
years of good service. If the battery tests good but still fails to perform well, the following are
some of the more common causes:

A vehicle accessory was left on overnight.

The driving speeds have been slow with frequent stops with many electrical accessories in
use, particularly air conditioning, headlights, wipers, heated rear window, cellular
telephone, etc.

The electrical load has exceeded the generator output, particularly with the addition of
aftermarket equipment.

Existing conditions in the charging system, including the following possibilities:

A slipping belt

A bad generator

The battery has not been properly maintained, including a loose battery hold down or
missing battery insulator if used.

There are mechanical conditions in the electrical system, such as a short or a pinched wire,
attributing to power failure. Refer to General Electrical Diagnosis Procedures in Wiring
Systems.

Electrolyte Freezing

The freezing point of electrolyte depends on its specific gravity. A fully charged battery will not
freeze until the ambient temperature gets below -54°C (-65°F). However, a battery with a low
state of charge may freeze at temperatures as high as -7°C (+20°F). Since freezing may ruin a
battery, the battery should be protected against freezing by keeping it properly charged. As long
as the green eye is visible in the hydrometer, the freezing point of the battery will be somewhere
below -32°C (-25°F).

Battery Protection During Vehicle Storage

Certain devices on the vehicle maintain a small continuous current drain on the battery. A battery
that is not used for an extended period of time will discharge. Eventually permanent damage will
result. Discharged batteries will also freeze in cold weather. Refer to Battery Inspection/Test
(Non-HP2).

In order to maintain a battery state of charge while storing the vehicle for more than 30 days:

2006 Hummer H3

2006 ENGINE Engine Electrical - H3

1. Ensure that the green dot is visible in the built-in hydrometer.

2. Disconnect the battery ground to protect the battery from discharge by parasitic current

drains.

When the battery cannot be disconnected:

1. Maintain a high state of charge.

2. Establish a regular schedule for recharging the battery every 20-45 days.

A battery that has remained in a discharged state for a long period of time is difficult to recharge
or may be permanently damaged.

JUMP STARTING IN CASE OF EMERGENCY (NON HP2)

IMPORTANT: If a green dot is not visible in the hydrometer, charge the

battery. Refer to Battery Charging.

CAUTION: Refer to Battery Disconnect Caution in Cautions and

Notices.

CAUTION: Batteries produce explosive gases. Batteries contain

corrosive acid. Batteries supply levels of electrical current
high enough to cause burns. Therefore, in order to reduce the
risk of personal injury while working near a battery, observe
the following guidelines:

Always shield your eyes.

Avoid leaning over the battery whenever possible.

Do not expose the battery to open flames or sparks.

Do not allow battery acid to contact the eyes or the skin.

Flush any contacted areas with water immediately
and thoroughly.

Get medical help.

NOTE:

This vehicle has a 12 volt, negative ground electrical system. Make
sure the vehicle or equipment being used to jump start the engine
is also 12 volt, negative ground. Use of any other type of system will

2006 Hummer H3

2006 ENGINE Engine Electrical - H3

This vehicle has a 12-volt positive, negative ground electrical system. Do not try to jump start a
vehicle, if you are unsure of the other vehicle's positive voltage or ground position. The booster
battery and the discharged battery should be treated carefully when using jumper cables.

1. Position the vehicle with the booster battery so that the jumper cables will comfortably

reach the battery of the other vehicle.

Do not let the 2 vehicles touch.

Make sure that the jumper cables do not have loose clamps or missing insulation.

2. Perform the following steps on both vehicles:

1. Place the automatic transmission in PARK.

2. Block the wheels.

3. Set the parking brake.

4. Turn off all electrical loads that are not needed. Leave the hazard flashers ON.

5. Turn OFF the ignition switch.

damage the vehicle's electrical components.

2006 Hummer H3

2006 ENGINE Engine Electrical - H3

Fig. 8: Identifying Proper Jumper Cable Connection
Courtesy of GENERAL MOTORS CORP.

IMPORTANT: Some vehicles have a battery remote positive stud. ALWAYS

use the battery remote positive stud in order to give or to
receive a jump start. Consult the vehicle's owner's manual

2006 Hummer H3

2006 ENGINE Engine Electrical - H3