SMU - Revised Battery Pack Discharge Test

This bulletin revises the Battery Pack Discharge Test in the Battery Pack Controls and Internal Battery Pack Controls subsection of the Propulsion System in the Service Manual in order to more accurately identify a defective Battery Module.

The previous test was run until 38.4 amp-hrs were discharged from the battery pack. Based on the Battery Pack Control Module (BPCM) DTCs that were set at this point, the test would either pass or fail batteries. A snapshot was available to view the last 10 amp-hrs of the test.

The new test will run exactly like the old test up to 38.4 amp-hrs (lead-acid), 48.0 amp-hrs (TP-6 High Capacity lead-acid), or 68.8 amp-hrs (NiMH) unless no DTCs are present. If no DTCs are present after 38.4 amp-hrs (lead-acid), 48.0 amp-hrs (TP-6 High Capacity lead- acid), or 68.8 amp-hrs (NiMH), then the test will continue to run until the first module reaches 10.5 volts (lead-acid), 9.9 volts (TP-6 High Capacity lead-acid), or 11.00 volts (NiMH), or the Battery Pack reaches 46 (lead-acid), 58 (TP-6 High Capacity lead-acid), or 75.6 (NiMH) amp-hrs. At that time the test will be terminated and the Tech 2 software will then conduct a calculation in order to determine if any modules need replacement. A snapshot will be available to view once the test is complete.

If a battery module is replaced, it is important to notify the customer that 3 complete charge/discharge cycles may be needed before an improvement in range may be noticed.

The discharge test is currently available on Techline CD 23 (Nov. '98) and all future Techline releases.