Tesla Powerwall › Problems
Powerwall drains below the backup reserve or down to 0%
The Powerwall's charge falls below the backup reserve, sometimes to 0%, or drops steadily while it sits idle. This page covers what the app message means, what to check first, and the causes behind it.
Error codes that go with this problem
| Code | What it means |
|---|---|
| your powerwall has 0% battery and is going into standby | The battery has drained past the backup reserve to 0%. It has appeared during a cold snap with snow on the panels and no outage. |
What to check first
- Look for a calibration banner in the app. A calibration cycle can drain the battery below the reserve, and it can be delayed once by 72 hours from the banner.
- If a calibration is draining the battery, triggering a Storm Watch event by hand interrupts it and forces a full charge.
- In the app, compare the drop in charge with the house and grid use over the same 15 minutes. A big drop with no matching use, such as 17% with 0.8 kWh used, is a reporting glitch rather than a real discharge.
- Note when the drain started and whether a firmware update went in just before.
- If the battery keeps draining further below the reserve, switching to backup-only mode has stopped it.
- If the battery stays at 0%, or the unit shows a fault after a calibration, it needs your installer or Tesla.
The causes and the fixes
Partners see the causes behind this problem, most common first, the checks that tell them apart, and the fix for each, with part numbers and recent prices when a part is involved.