Battery Charging: Notes

WARNING: This page is about a different car, the 2002 Buick Regal and 2002 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.

Tools Required : J 42000 Battery Tester

For best results, use an automatic taper-rate battery charger with a voltage capability of 16 volts.
A battery showing a green dot in the hydrometer (1) does not need to be charged unless the J 42000 has shown that the battery needs to be charged.

Fig 1: Identifying Battery Hydrometer Dot Results

Courtesy of GENERAL MOTORS CORP.

A battery showing a dark dot in the hydrometer (2) should be charged unless the 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.