diff --git a/charger/keba.go b/charger/keba.go
index f886c8d28..aaf265ebf 100644
--- a/charger/keba.go
+++ b/charger/keba.go
@@ -40,33 +40,36 @@ type Keba struct {
 func NewKebaFromConfig(other map[string]interface{}) (api.Charger, error) {
 	cc := struct {
 		URI     string
+		Serial  string
 		Timeout time.Duration
 		RFID    RFID
-	}{}
+	}{
+		Timeout: udpTimeout,
+	}
 	if err := util.DecodeOther(other, &cc); err != nil {
 		return nil, err
 	}
 
-	return NewKeba(cc.URI, cc.RFID, cc.Timeout)
+	return NewKeba(cc.URI, cc.Serial, cc.RFID, cc.Timeout)
 }
 
 // NewKeba creates a new charger
-func NewKeba(conn string, rfid RFID, timeout time.Duration) (api.Charger, error) {
+func NewKeba(conn, serial string, rfid RFID, timeout time.Duration) (api.Charger, error) {
 	log := util.NewLogger("keba")
 
+	var err error
 	if keba.Instance == nil {
-		keba.Instance = keba.New(log, fmt.Sprintf(":%s", kebaPort))
+		keba.Instance, err = keba.New(log, fmt.Sprintf(":%s", kebaPort))
+		if err != nil {
+			return nil, err
+		}
 	}
 
 	// add default port
-	if _, _, err := net.SplitHostPort(conn); err != nil {
+	if _, _, err = net.SplitHostPort(conn); err != nil {
 		conn = fmt.Sprintf("%s:%s", conn, kebaPort)
 	}
 
-	if timeout == 0 {
-		timeout = udpTimeout
-	}
-
 	c := &Keba{
 		log:     log,
 		conn:    conn,
@@ -75,9 +78,12 @@ func NewKeba(conn string, rfid RFID, timeout time.Duration) (api.Charger, error)
 		recv:    make(chan keba.UDPMsg),
 	}
 
-	keba.Instance.Subscribe(conn, c.recv)
+	// use serial to subscribe if defined for docker scenarios
+	if serial == "" {
+		serial = conn
+	}
 
-	return c, nil
+	return c, keba.Instance.Subscribe(serial, c.recv)
 }
 
 func (c *Keba) send(msg string) error {
@@ -226,32 +232,43 @@ func (c *Keba) Enable(enable bool) error {
 		d = 1
 	}
 
+	// ignore result...
 	var resp string
-	err := c.roundtrip(fmt.Sprintf("ena %d", d), 0, &resp)
+	_ = c.roundtrip(fmt.Sprintf("ena %d", d), 0, &resp)
+
+	// ...and verify value
+	res, err := c.Enabled()
+	if err == nil && res != enable {
+		return fmt.Errorf("ena could not enable: %s", resp)
+	}
+
+	return err
+}
+
+// actualCurrent returns the actual current
+func (c *Keba) actualCurrent() (int64, error) {
+	var kr keba.Report2
+	err := c.roundtrip("report 2", 2, &kr)
 	if err != nil {
-		return err
+		return 0, err
 	}
 
-	if string(resp) == keba.OK {
-		return nil
-	}
-
-	return fmt.Errorf("ena unexpected response: %s", resp)
+	return int64(kr.Curruser) / 1000, nil
 }
 
 // MaxCurrent implements the Charger.MaxCurrent interface
 func (c *Keba) MaxCurrent(current int64) error {
+	// ignore result...
 	var resp string
-	err := c.roundtrip(fmt.Sprintf("curr %d", 1000*current), 0, &resp)
-	if err != nil {
-		return err
+	_ = c.roundtrip(fmt.Sprintf("curr %d", 1000*current), 0, &resp)
+
+	// ...and verify value
+	res, err := c.actualCurrent()
+	if err == nil && res != current {
+		return fmt.Errorf("curr could not set: %s", resp)
 	}
 
-	if resp == keba.OK {
-		return nil
-	}
-
-	return fmt.Errorf("curr unexpected response: %s", resp)
+	return err
 }
 
 // CurrentPower implements the Meter interface
diff --git a/charger/keba/listener.go b/charger/keba/listener.go
index ce11c2769..bb2c2bdd2 100644
--- a/charger/keba/listener.go
+++ b/charger/keba/listener.go
@@ -2,6 +2,7 @@ package keba
 
 import (
 	"encoding/json"
+	"fmt"
 	"net"
 	"strings"
 	"sync"
@@ -36,37 +37,39 @@ type Listener struct {
 }
 
 // New creates a UDP listener that clients can subscribe to
-func New(log *util.Logger, addr string) *Listener {
+func New(log *util.Logger, addr string) (*Listener, error) {
 	laddr, err := net.ResolveUDPAddr("udp", addr)
 	if err != nil {
-		log.FATAL.Fatal(err)
+		return nil, err
 	}
 
 	conn, err := net.ListenUDP("udp", laddr)
 	if err != nil {
-		log.FATAL.Fatal(err)
+		return nil, err
 	}
 
 	l := &Listener{
-		log:  log,
-		conn: conn,
+		log:     log,
+		conn:    conn,
+		clients: make(map[string]chan<- UDPMsg),
 	}
 
 	go l.listen()
 
-	return l
+	return l, nil
 }
 
 // Subscribe adds a client address and message channel
-func (l *Listener) Subscribe(addr string, c chan<- UDPMsg) {
+func (l *Listener) Subscribe(addr string, c chan<- UDPMsg) error {
 	l.mux.Lock()
 	defer l.mux.Unlock()
 
-	if l.clients == nil {
-		l.clients = make(map[string]chan<- UDPMsg)
+	if _, exists := l.clients[addr]; exists {
+		return fmt.Errorf("duplicate subscription: %s", addr)
 	}
 
 	l.clients[addr] = c
+	return nil
 }
 
 func (l *Listener) listen() {
@@ -75,7 +78,7 @@ func (l *Listener) listen() {
 	for {
 		read, addr, err := l.conn.ReadFrom(b)
 		if err != nil {
-			l.log.WARN.Printf("listener: %v", err)
+			l.log.ERROR.Printf("listener: %v", err)
 			continue
 		}
 
@@ -101,12 +104,24 @@ func (l *Listener) listen() {
 	}
 }
 
+// addrMatches checks if either message sender or serial matched given addr
+func (l *Listener) addrMatches(addr string, msg UDPMsg) bool {
+	switch {
+	case addr == msg.Addr:
+		return true
+	case msg.Report != nil && addr == msg.Report.Serial:
+		return true
+	default:
+		return false
+	}
+}
+
 func (l *Listener) send(msg UDPMsg) {
 	l.mux.Lock()
 	defer l.mux.Unlock()
 
 	for addr, client := range l.clients {
-		if addr == msg.Addr {
+		if l.addrMatches(addr, msg) {
 			select {
 			case client <- msg:
 			default:
diff --git a/charger/keba_test.go b/charger/keba_test.go
index 9816e5e4d..0588968d3 100644
--- a/charger/keba_test.go
+++ b/charger/keba_test.go
@@ -8,7 +8,7 @@ import (
 
 func TestKeba(t *testing.T) {
 	var wb api.Charger
-	wb, err := NewKeba("foo", RFID{}, 0)
+	wb, err := NewKeba("foo", "bar", RFID{}, 0)
 	if err != nil {
 		t.Error(err)
 	}