Tesla Powerwall › battery pack
Powerwall calibration banner, discharges to 0% after update
reported in the field
Symptoms
- A Powerwall 2 or Powerwall+ that ran five to nine years without calibrating shows a calibration banner in the app after firmware 26.18.x (mid-2026), charges to 100% then discharges to 0% ignoring the backup reserve, sometimes with every unit of a multi-unit system discharged at once
- In several reports the unit is disabled after the cycle and Tesla schedules a warranty replacement
The cause and the fix
Subscribers see the cause, the fixes that worked and who did them, part numbers and recent prices when a part is involved, and the field reports behind this entry.