Applicable Systems
Powerpack 2
Symptoms
The Tesla Powerpack BMS displays alert BMS_a069, indicating the high voltage battery charge level is too low to support normal operation.
Possible Causes
- Battery pack energy depleted below the minimum safe operating level
- Self-discharge over extended storage period without maintenance charging
- Auxiliary loads draining the battery while the system is idle
- Charging system failure preventing proper recharge of the pack
Troubleshooting Steps
- Step 1: Connect a compatible charger to recharge the battery pack
Charging must restore the pack to at least the minimum operating state of charge - Step 2: Verify the charging system is functioning properly
Charger must deliver rated current; check for charger faults or communication errors - Step 3: Check for parasitic loads draining the battery during idle periods
All auxiliary loads should be minimal when the system is in standby - Step 4: If the pack has been deeply discharged, contact Tesla service
Deeply discharged lithium-ion packs may require special recovery procedures
How to Reset
To reset: 1) Recharge the battery pack to an adequate state of charge. 2) The alert should clear automatically once sufficient charge is confirmed. 3) If the alert persists after charging, contact Tesla Energy service. Caution: Deep discharge can permanently reduce battery capacity.
Frequently Asked Questions
- Q: What state of charge triggers BMS_a069?
BMS_a069 triggers when the high voltage battery does not have enough energy remaining to support normal operation. The exact threshold depends on the pack configuration but is typically below 5-10% SoC.
- Q: Can a deeply discharged Powerpack be recovered?
Recovery may be possible with Tesla service intervention. Do not attempt to charge a deeply discharged pack without following Tesla's recovery procedure, as this can be a fire hazard.
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Source: Tesla Powerpack Owner's Manual, Troubleshooting Alerts, BMS_a069
Category: Battery
Published: 2026-10-21
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