diff --git a/mission/controller/PowerController.cpp b/mission/controller/PowerController.cpp
index 8fb774dc..e4ad9f81 100644
--- a/mission/controller/PowerController.cpp
+++ b/mission/controller/PowerController.cpp
@@ -182,7 +182,7 @@ void PowerController::calculateStateOfCharge() {
   }
 
   // calculate total battery current
-  iBat = p60CoreHk.batteryCurrent.value + bpxBatteryHk.dischargeCurrent.value;
+  iBat = p60CoreHk.batteryCurrent.value - bpxBatteryHk.dischargeCurrent.value;
 
   result = calculateOpenCircuitVoltageCharge();
   if (result != returnvalue::OK) {