Grab your SMA Energy App and click on the 'My area' icon at the bottom right

Locate the QR-code on your inverter: inside the red circle on this picture

Click on "Quick access to devices" in the SMA Energy app. Your phone will usually ask if you want to grant the app access to your camera: grant permission.

Point the scanner at the QR code: the login screen will now open

Log in on the inverter user interface with the user group 'Installer' and the password made up of: 0+your postcode+_zf

Go to the user settings and launch the 'Installation Assistant'

The installation assistant will take you through a series of screens where you don't need to do anything. Click "Save and Continue" or "Continue" on each page until you reach the correct page.

After a few pages, you'll arrive at the "Battery-backup system" section. Here you can adjust the battery capacity percentage under the heading "Lower battery charge limit."

Once you have entered the desired value, click 'Save and next'

Continue until you reach the summary. Scroll down. You'll see the value that you set in the summary. Click "Continue." This completes the setup.

You have now set a minimum reserve. If the battery charge is below the set minimum at the time you set this, it will initially charge to that level. From then on, this limit remains the lower limit of the charge, unless the public grid fails and the reserve needs to be used for backup power.