diff --git a/packages/modules/devices/sma/sma_sunny_boy/bat_smart_energy.py b/packages/modules/devices/sma/sma_sunny_boy/bat_smart_energy.py
index ee871c019a..cdb788be2e 100644
--- a/packages/modules/devices/sma/sma_sunny_boy/bat_smart_energy.py
+++ b/packages/modules/devices/sma/sma_sunny_boy/bat_smart_energy.py
@@ -113,7 +113,7 @@ def set_power_limit(self, power_limit: Optional[int]) -> None:
             log.debug("Aktive Batteriesteuerung vorhanden. Setze externe Steuerung.")
             values_to_write = {
                 "Externe_Steuerung": 802,
-                "Wirkleistungsvorgabe": abs(power_limit)
+                "Wirkleistungsvorgabe": int(power_limit) * -1
             }
             self._write_registers(values_to_write, unit)
             self.last_mode = 'limited'