diff --git a/charger/ocpp/cs.go b/charger/ocpp/cs.go
index e13ce7c3fc..46b6072f77 100644
--- a/charger/ocpp/cs.go
+++ b/charger/ocpp/cs.go
@@ -57,11 +57,12 @@ func (cs *CS) NewChargePoint(chargePoint ocpp16.ChargePointConnection) {
 
 	if cp, err := cs.chargepointByID(chargePoint.ID()); err != nil {
 		// check for anonymous chargepoint
-		if cp, ok := cs.cps[""]; ok {
+		if cp, err := cs.chargepointByID(""); err == nil {
 			cs.log.INFO.Printf("chargepoint connected, registering: %s", chargePoint.ID())
 
 			// update id
 			cp.RegisterID(chargePoint.ID())
+
 			cs.cps[chargePoint.ID()] = cp
 			delete(cs.cps, "")
 
diff --git a/charger/ocpp/cs_core.go b/charger/ocpp/cs_core.go
index b96efc26a9..1b70dca6f0 100644
--- a/charger/ocpp/cs_core.go
+++ b/charger/ocpp/cs_core.go
@@ -53,6 +53,9 @@ func (cs *CS) TriggerMeterValuesRequest(id string, connector int) {
 // cp actions
 
 func (cs *CS) OnAuthorize(id string, request *core.AuthorizeRequest) (*core.AuthorizeConfirmation, error) {
+	cs.mu.Lock()
+	defer cs.mu.Unlock()
+
 	cp, err := cs.chargepointByID(id)
 	if err != nil {
 		return nil, err
@@ -62,6 +65,9 @@ func (cs *CS) OnAuthorize(id string, request *core.AuthorizeRequest) (*core.Auth
 }
 
 func (cs *CS) OnBootNotification(id string, request *core.BootNotificationRequest) (*core.BootNotificationConfirmation, error) {
+	cs.mu.Lock()
+	defer cs.mu.Unlock()
+
 	cp, err := cs.chargepointByID(id)
 	if err != nil {
 		return nil, err
@@ -71,6 +77,9 @@ func (cs *CS) OnBootNotification(id string, request *core.BootNotificationReques
 }
 
 func (cs *CS) OnDataTransfer(id string, request *core.DataTransferRequest) (*core.DataTransferConfirmation, error) {
+	cs.mu.Lock()
+	defer cs.mu.Unlock()
+
 	cp, err := cs.chargepointByID(id)
 	if err != nil {
 		return nil, err
@@ -80,6 +89,9 @@ func (cs *CS) OnDataTransfer(id string, request *core.DataTransferRequest) (*cor
 }
 
 func (cs *CS) OnHeartbeat(id string, request *core.HeartbeatRequest) (*core.HeartbeatConfirmation, error) {
+	cs.mu.Lock()
+	defer cs.mu.Unlock()
+
 	cp, err := cs.chargepointByID(id)
 	if err != nil {
 		return nil, err
@@ -89,6 +101,9 @@ func (cs *CS) OnHeartbeat(id string, request *core.HeartbeatRequest) (*core.Hear
 }
 
 func (cs *CS) OnMeterValues(id string, request *core.MeterValuesRequest) (*core.MeterValuesConfirmation, error) {
+	cs.mu.Lock()
+	defer cs.mu.Unlock()
+
 	cp, err := cs.chargepointByID(id)
 	if err != nil {
 		return nil, err
@@ -98,6 +113,9 @@ func (cs *CS) OnMeterValues(id string, request *core.MeterValuesRequest) (*core.
 }
 
 func (cs *CS) OnStatusNotification(id string, request *core.StatusNotificationRequest) (*core.StatusNotificationConfirmation, error) {
+	cs.mu.Lock()
+	defer cs.mu.Unlock()
+
 	cp, err := cs.chargepointByID(id)
 	if err != nil {
 		return nil, err
@@ -107,6 +125,9 @@ func (cs *CS) OnStatusNotification(id string, request *core.StatusNotificationRe
 }
 
 func (cs *CS) OnStartTransaction(id string, request *core.StartTransactionRequest) (*core.StartTransactionConfirmation, error) {
+	cs.mu.Lock()
+	defer cs.mu.Unlock()
+
 	cp, err := cs.chargepointByID(id)
 	if err != nil {
 		return nil, err
@@ -116,6 +137,9 @@ func (cs *CS) OnStartTransaction(id string, request *core.StartTransactionReques
 }
 
 func (cs *CS) OnStopTransaction(id string, request *core.StopTransactionRequest) (*core.StopTransactionConfirmation, error) {
+	cs.mu.Lock()
+	defer cs.mu.Unlock()
+
 	cp, err := cs.chargepointByID(id)
 	if err != nil {
 		return nil, err
@@ -125,6 +149,9 @@ func (cs *CS) OnStopTransaction(id string, request *core.StopTransactionRequest)
 }
 
 func (cs *CS) OnDiagnosticsStatusNotification(id string, request *firmware.DiagnosticsStatusNotificationRequest) (confirmation *firmware.DiagnosticsStatusNotificationConfirmation, err error) {
+	cs.mu.Lock()
+	defer cs.mu.Unlock()
+
 	cp, err := cs.chargepointByID(id)
 	if err != nil {
 		return nil, err
@@ -134,6 +161,9 @@ func (cs *CS) OnDiagnosticsStatusNotification(id string, request *firmware.Diagn
 }
 
 func (cs *CS) OnFirmwareStatusNotification(id string, request *firmware.FirmwareStatusNotificationRequest) (confirmation *firmware.FirmwareStatusNotificationConfirmation, err error) {
+	cs.mu.Lock()
+	defer cs.mu.Unlock()
+
 	cp, err := cs.chargepointByID(id)
 	if err != nil {
 		return nil, err