diff --git a/src/WebApi_ws_battery.cpp b/src/WebApi_ws_battery.cpp
index 669df955f..be904f715 100644
--- a/src/WebApi_ws_battery.cpp
+++ b/src/WebApi_ws_battery.cpp
@@ -67,6 +67,9 @@ void WebApiWsBatteryLiveClass::sendDataTaskCb()
             JsonVariant var = root;
             generateJsonResponse(var);
 
+            // battery provider does not generate a card, e.g., MQTT provider
+            if (root.isNull()) { return; }
+
             String buffer;
             serializeJson(root, buffer);
 
diff --git a/src/WebApi_ws_live.cpp b/src/WebApi_ws_live.cpp
index e838b1d1d..127259236 100644
--- a/src/WebApi_ws_live.cpp
+++ b/src/WebApi_ws_live.cpp
@@ -121,6 +121,8 @@ void WebApiWsLiveClass::sendOnBatteryStats()
     if (all) { _lastPublishOnBatteryFull = millis(); }
     generateOnBatteryJsonResponse(var, all);
 
+    if (root.isNull()) { return; }
+
     String buffer;
     serializeJson(root, buffer);