GM Service Manual Online
For 1990-2009 cars only
    • For best results, use an automatic taper-rate battery charger with a voltage capability of 16 volts.

Object Number: 181056  Size: SH
    • A battery showing a green dot in the hydrometer (1) does not need to be charged unless the J 42000 Battery Tester has shown that the battery needs to be charged.
    • A battery showing a dark green dot in the hydrometer (2) should be charged unless J 42000 has indicated no charge is needed.
    • Do not charge a battery when the built in hydrometer is clear or yellow in the center (3). Tap the hydrometer lightly in order to dislodge any air bubbles. The bubbles may cause a false indication. If the hydrometer is still clear or yellow, replace the battery.
    • The charging area should be well ventilated.
    • Do not charge a battery that appears to be frozen. Allow the battery to warm to room temperature and test it before charging.

Charging Time Required

The time required to charge a battery will vary depending upon the following factors:

  1. The battery charger capacity--The higher the chargers amperage, the less time it will take to charge the battery.
  2. The state-of-charge of the battery--A completely discharged battery requires more than twice as much charging time as a half charged battery. In a discharged battery with a voltage below 11 volts, the battery has a very high internal resistance and may only accept a very low current at first. Later, as the charging current causes the acid content to increase in the electrolyte, the charging current will increase. Extremely discharged batteries may not activate the reversed voltage protection in some chargers. Refer to the manufacturer's instructions for operating this circuitry.
  3. The temperature of the battery--The colder the battery is, the more time it takes to recharge the battery. The charging current accepted by a cold battery is very low at first: then, as the battery warms, the charging current will increase.

Charging Procedure

Caution: Turn off the ignition key when disconnecting or reconnecting battery power in order to prevent system damage.

Caution: Refer to Fastener Caution in the Preface section.

Use the following procedure to charge the battery:

  1. Turn OFF the charger.
  2. Ensure that all of the battery terminal connections are clean and tight.
  3. Connect the charger positive lead to the battery positive terminal.
  4. Note: Do not connect the negative charger lead to the housings of other vehicle electrical accessories or equipment. The action of the battery charger may damage such equipment.

  5. Connect the negative charger lead to a solid engine ground or to a ground stud in the engine compartment that is connected directly to the battery negative terminal, but away from the battery. If the negative battery cable is disconnected and a terminal adapter is being used, connect directly to the adapter.
  6. Turn ON the charger and set to the highest setting for normal charging.
  7. Inspect the battery every half hour after starting the battery charger.
  8. • Charge the battery until the hydrometer has a green dot or until the taper-rate charger indicates that the battery is fully charged, whichever occurs first.
    • Tap the hydrometer lightly in order to dislodge any air bubbles. The bubbles may cause a false indication.
    • Estimate the battery temperature by feeling the side of the battery. If it feels hot to the touch or its temperature is over 45°C (125°F), discontinue charging and allow the battery to cool before resuming charging.
  9. After charging, test the battery. Refer to Battery Inspection/Test.