diff --git a/rust/src/hal/battery.rs b/rust/src/hal/battery.rs
index 2165970..cf12f06 100644
--- a/rust/src/hal/battery.rs
+++ b/rust/src/hal/battery.rs
@@ -38,9 +38,10 @@ pub struct BatteryInfo {
 }
 
 #[derive(Debug, Serialize)]
+#[serde(tag = "kind")]
 pub enum BatteryError {
     NoBatteryMonitor,
-    CommunicationError(String),
+    CommunicationError { message: String },
 }
 
 #[derive(Debug, Serialize)]