diff --git a/assets/js/app.js b/assets/js/app.js
index 0c2787a94..0e9deefc1 100644
--- a/assets/js/app.js
+++ b/assets/js/app.js
@@ -222,4 +222,5 @@ const router = new VueRouter({
 const app = new Vue({
   router,
 }).$mount("#app");
-store.init;
\ No newline at end of file
+
+store.init();
diff --git a/core/api.go b/core/api.go
index 0c02f5c90..b1c79240b 100644
--- a/core/api.go
+++ b/core/api.go
@@ -7,10 +7,10 @@ import (
 	"github.com/andig/evcc/core/wrapper"
 )
 
-// NilVal implements Stringer for nil values
-type NilVal int
+// nilVal implements Stringer for nil values
+type nilVal int
 
-func (n *NilVal) String() string {
+func (n *nilVal) String() string {
 	return "—"
 }
 
@@ -160,7 +160,7 @@ func (lp *LoadPoint) publishSoC() {
 		log.ERROR.Printf("%s vehicle error: %v", lp.Name, err)
 	}
 
-	var n *NilVal
+	var n *nilVal
 	lp.publish("socCharge", n)
 	lp.publish("chargeEstimate", -1)
 }
diff --git a/server/assets.go b/server/assets.go
index 902d4e98b..1424dcdd4 100644
--- a/server/assets.go
+++ b/server/assets.go
@@ -3824,39 +3824,39 @@ AP//MWVC4HgxAAA=
 	"/js/app.js": {
 		name:    "app.js",
 		local:   "../assets/js/app.js",
-		size:    5012,
+		size:    5016,
 		modtime: 1566640112,
 		compressed: `
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 `,
 	},
 
diff --git a/server/socket.go b/server/socket.go
index 508684c75..120bc36a2 100644
--- a/server/socket.go
+++ b/server/socket.go
@@ -82,32 +82,33 @@ func NewSocketHub() *SocketHub {
 	}
 }
 
-func (h *SocketHub) encode(v core.Param) ([]byte, error) {
+func encode(v interface{}) (string, error) {
 	var s string
-	switch val := v.Val.(type) {
+	switch val := v.(type) {
 	case time.Duration:
 		// must be before stringer to convert to seconds instead of string
-		s = fmt.Sprintf("{\"%s\": %d}", v.Key, int64(val.Seconds()))
+		s = fmt.Sprintf("%d", int64(val.Seconds()))
 	case fmt.Stringer, string:
-		s = fmt.Sprintf("{\"%s\": \"%s\"}", v.Key, val)
+		s = fmt.Sprintf("\"%s\"", val)
 	case float64:
-		s = fmt.Sprintf("{\"%s\": %.3f}", v.Key, val)
+		s = fmt.Sprintf("%.3f", val)
 	default:
-		s = fmt.Sprintf("{\"%s\": %v}", v.Key, val)
+		s = fmt.Sprintf("%v", val)
 	}
-	return []byte(s), nil
+	return s, nil
 }
 
 func (h *SocketHub) broadcast(i core.Param) {
 	if len(h.clients) > 0 {
-		message, err := h.encode(i)
+		val, err := encode(i.Val)
 		if err != nil {
 			log.FATAL.Fatal(err)
 		}
+		message := fmt.Sprintf("{\"%s\": %s}", i.Key, val)
 
 		for client := range h.clients {
 			select {
-			case client.send <- message:
+			case client.send <- []byte(message):
 			default:
 				close(client.send)
 				delete(h.clients, client)
diff --git a/server/socket_test.go b/server/socket_test.go
new file mode 100644
index 000000000..3d37bee76
--- /dev/null
+++ b/server/socket_test.go
@@ -0,0 +1,41 @@
+package server
+
+import (
+	"reflect"
+	"testing"
+	"time"
+)
+
+type nilVal int
+
+func (n *nilVal) String() string {
+	return "—"
+}
+
+func TestEncode(t *testing.T) {
+	var nv nilVal
+	tc := []struct {
+		in, out interface{}
+	}{
+		{int64(1), "1"},
+		{float64(1.2345), "1.234"},
+		{"1.2345", "\"1.2345\""},
+		{&nv, "\"—\""},
+		{time.Duration(time.Hour), "3600"},
+		{"minpv", "\"minpv\""},
+	}
+
+	for _, tc := range tc {
+		t.Logf("%+v", tc)
+		out, err := encode(tc.in)
+		if err != nil {
+			t.Error(err)
+		}
+
+		if out != tc.out {
+			t.Errorf("expected %v (string), got %v (%s)",
+				tc.out, out, reflect.TypeOf(out).Kind(),
+			)
+		}
+	}
+}