What backup reserve values can be used?
Tesla currently allows the Powerwall backup reserve to be set to the following values:
Backup reserve values between 81% and 99% are not supported by Tesla.
MAP Energy will not submit a backup reserve value between 81% and 99% to Tesla.
Why does this restriction exist?
This is a Tesla Powerwall restriction rather than a limitation introduced by MAP Energy.
MAP Energy communicates with your Powerwall through Tesla's services, so any backup reserve change must use a value that Tesla currently accepts.
How does this affect MAP Energy automations?
MAP Energy has been built to account for Tesla's backup reserve restrictions when creating and running automations.
When an automation directly sets the Powerwall backup reserve, MAP Energy only allows supported values to be selected.
This means MAP Energy will not intentionally submit a backup reserve between 81% and 99% to Tesla.
What happens when an automation captures my current reserve?
Some MAP Energy automations temporarily change your Powerwall settings and then restore your previous backup reserve when the automation finishes.
In these cases, MAP Energy can capture the backup reserve that was active before the automation started.
If the captured reserve is between 81% and 99%, MAP Energy cannot send that value back to Tesla when restoring your settings.
When configuring an automation that uses this behaviour, you choose what MAP Energy should do if the captured value falls within Tesla's unsupported range.
Use an 80% backup reserve when the captured value is between 81% and 99%.
Use a 100% backup reserve when the captured value is between 81% and 99%.
You choose whether MAP Energy should use 80% or 100% when a captured backup reserve falls within Tesla's unsupported 81–99% range.
Change reserve in the Web Portal
In the Premium Web Portal, open Live and select Backup. Move the slider through 0–80%, then directly to 100%, and select Confirm. The portal checks the refreshed Powerwall setting; if confirmation is unavailable, refresh before retrying.
The automation editor uses the same slider range. You can create or edit a reserve action in portal Automations, and pause or resume supported rules.
Using 100% backup reserve
Setting the backup reserve to 100% can be useful when you want to prevent the Powerwall from supplying normal household demand.
This can be particularly useful within MAP Energy automations that temporarily need to preserve the energy stored in your Powerwall.
When the automation finishes, MAP Energy can restore the previously captured backup reserve. If that captured value was between 81% and 99%, your selected 80% or 100% fallback preference will be used instead.
The fallback only applies when the reserve MAP Energy captured cannot be restored because it falls within Tesla's unsupported 81–99% range.
Need help?
If an automation is not changing your Powerwall backup reserve as expected, check the automation history in MAP Energy. This can help confirm whether the action was successfully sent to Tesla.
You can also contact MAP Energy support if you need help diagnosing an automation or Powerwall control issue.