Diagnostic Aids
- Rule out any possible obvious influences, such as customer error or aftermarket equipment.
- Check customer driving habits, such as regular short trips. This does not allow enough time to properly charge the battery. Refer to BATTERY DESCRIPTION AND OPERATION .
- Verify that the battery and charging system are in proper working order. Refer to BATTERY CHARGING and CHARGING SYSTEM TEST .
- A battery discharging for no apparent reason while the vehicle is parked can be caused by an intermittent draw, such as a module waking up, or a continuous draw, such as a dome light or stuck relay.
- Some systems and modules such as OnStar®, and regulated voltage control (RVC), if equipped, are designed to wake-up, perform a task, and go back asleep at regular intervals. Refer to CONTROL MODULE REFERENCES for the system or modules description and operation.
- Some systems and modules such as theft, or remote keyless entry (RKE) will wake up due to an outside input. Refer to CONTROL MODULE REFERENCES
for the system or modules description and operation.NOTE: The battery specification listed below is a generic specification. Refer to table when testing the battery.
- The battery run down time will vary depending on cold cranking amperage (CCA) and reserve capacity (RC). If the CCA and RC are higher, then the battery run down time would be longer. If the CCA and RC are lower, then the battery run down time would be shorter. The graph below indicates roughly how many days a 690 CCA battery with at 110 min. RC (60.5 AH) starting at 80 percent state of charge will last with a constant current draw until it reaches 50 percent state of charge. Differences in battery rating and temperature will affect the results.
CURRENT DRAIN TABLE
| Current | Drain Days |
|---|---|
| 25 mA | 30.5 |
| 50 mA | 16.5 |
| 75 mA | 11 |
| 100 mA | 8.25 |
| 250 mA | 3.3 |
| 500 mA | 1.65 |
| 750 mA | 1 |
| 1 A | 0.8 |
| 2 A | 0.4 |