diff --git a/core/soc/estimator.go b/core/soc/estimator.go
index d296b655e..fa5d0591e 100644
--- a/core/soc/estimator.go
+++ b/core/soc/estimator.go
@@ -111,7 +111,7 @@ func (s *Estimator) Soc(fetchedSoc *float64, chargedEnergy float64) float64 {
 		// recalculate gradient, wh per soc %
 		if socDiff > 10 && energyDiff > 0 {
 			s.energyPerSocStep = energyDiff / socDiff
-			s.virtualCapacity = s.energyPerSocStep * 100
+			s.virtualCapacity = max(s.vehicle.Capacity()*1e3, s.energyPerSocStep*100)
 			s.log.DEBUG.Printf("soc gradient updated: soc: %.1f%%, socDiff: %.1f%%, energyDiff: %.0fWh, energyPerSocStep: %.1fWh, virtualCapacity: %.0fWh", s.vehicleSoc, socDiff, energyDiff, s.energyPerSocStep, s.virtualCapacity)
 		}
 
diff --git a/core/soc/estimator_test.go b/core/soc/estimator_test.go
index 84f3052bf..5edd30350 100644
--- a/core/soc/estimator_test.go
+++ b/core/soc/estimator_test.go
@@ -39,7 +39,7 @@ func TestSocEstimation(t *testing.T) {
 	charger := &chargerStruct{api.NewMockCharger(ctrl), api.NewMockBattery(ctrl)}
 
 	// 8.5 kWh user battery capacity is converted to initial value of 10 kWh virtual capacity (at 85% efficiency)
-	vehicle.EXPECT().Capacity().Return(8.5)
+	vehicle.EXPECT().Capacity().Return(8.5).AnyTimes()
 
 	ce := NewEstimator(util.NewLogger("foo"), charger, vehicle)
 
@@ -66,6 +66,7 @@ func TestSocEstimation(t *testing.T) {
 		{5001, 50.0, 100.0, 10000},
 		{0, 20.0, 20.0, 10000},
 		{1000, 30.0, 30.0, 10000},
+		{1000, 50.0, 50.0, 8500}, // cap virtual capacity minimum to physical capacity
 	}
 
 	for _, tc := range tc {