Tesla Powerwall Bug: Version 25.42.1 ignores Backup Reserve Settings

[manuelgruber]

Tesla Powerwall Bug: Version 25.42.1 ignores Backup Reserve Settings

Tesla Powerwall Backup Reserve Not Charging to Target Level

Description

The Backup Reserve feature on Tesla Powerwall is not functioning as expected after updating to software version 25.42.1. When setting a Backup Reserve level higher than the current state of charge (SOC), the Powerwall fails to charge from the grid to reach the configured reserve threshold.

This functionality is critical for PowerNight users who rely on scheduled grid charging during off-peak hours.

Environment

• Device: Tesla Powerwall 2 with Gateway 2
• Software Version: 25.42.1 - 1d1ff4c6 (updated on 2025-11-19)
• Feature Affected: Backup Reserve / Grid charging behavior

Steps to Reproduce

1. Update Powerwall to software version 25.42.1
2. Ensure the Powerwall state of charge is below 70% (like 50% as shown in the screenshot)
3. Set Backup Reserve to 70% in the Tesla App
4. Monitor system behavior over time (with no solar generation)
5. Observe behavior during PowerNight off-peak hours when grid charging should occur

Expected Behavior

When SOC is below the configured Backup Reserve (e.g., 50% SOC with 70% reserve setting), the Powerwall should:

• Stop discharging power to the house
• Begin charging from the grid to reach the configured Backup Reserve level
• Maintain the SOC at or above the Backup Reserve threshold

Actual Behavior

• Powerwall System does not respect the reserve threshold for switching to grid power
• If grid charging is enabled, no grid charging occurs to reach the 70% reserve threshold
• This behavior only started after updating to version 25.42.1

Powerwall is discharging at 50% SOC

While Powerwall Backup Reserve is set to 70%

And Grid Charging is enabled

Additional Information

• Previous software versions correctly charged from grid when SOC was below Backup Reserve setting
• Issue appears to be specifically related to the 25.42.1 update