diff --git a/src/charge_controller.rs b/src/charge_controller.rs
index 831e82f..9b58ee8 100644
--- a/src/charge_controller.rs
+++ b/src/charge_controller.rs
@@ -1,4 +1,7 @@
-use std::sync::{Arc, Mutex, MutexGuard};
+use std::{
+    sync::{Arc, Mutex, MutexGuard},
+    time::Duration,
+};
 
 use embedded_hal::digital::v2::{OutputPin, PinState};
 use embedded_svc::event_bus::{EventBus, Postbox};
@@ -8,10 +11,13 @@ use esp_idf_svc::eventloop::{
     EspSubscription, EspTypedEventDeserializer, EspTypedEventSerializer, EspTypedEventSource, User,
 };
 use esp_idf_sys::c_types;
-use log::{warn};
+use log::warn;
 use serde_json::json;
 
-use crate::voltage_detection::{VoltageDetectionWorker, VOLTAGE_EVENTLOOP};
+use crate::{
+    time::Time,
+    voltage_detection::{VoltageDetectionWorker, VOLTAGE_EVENTLOOP},
+};
 
 pub static mut CHARGE_STATE_EVENT_LOOP: Option<
     EspEventLoop<esp_idf_svc::eventloop::User<Background>>,
@@ -27,6 +33,7 @@ pub enum ChargeStatus {
 pub struct ChargeControllerState {
     pub status: ChargeStatus,
     pub pin_state: PinState,
+    pub charge_deadline_at: Duration,
 }
 
 impl ChargeControllerState {
@@ -34,6 +41,7 @@ impl ChargeControllerState {
         Self {
             status: ChargeStatus::Charging,
             pin_state: PinState::Low,
+            charge_deadline_at: Duration::ZERO,
         }
     }
 
@@ -46,7 +54,13 @@ impl ChargeControllerState {
             PinState::Low => "Low",
             PinState::High => "High",
         };
-        json!({ "status": status, "pin_state": pin_state}).to_string()
+        let now = Time::new().get_time();
+        let charging_count_down = if now > self.charge_deadline_at {
+            -1i64
+        } else {
+            (self.charge_deadline_at - now).as_secs() as i64
+        };
+        json!({ "status": status, "pin_state": pin_state, "charging_count_down": charging_count_down}).to_string()
     }
 }
 
@@ -112,7 +126,14 @@ impl ChargeController {
                             if obj.battery_voltage < 12600 {
                                 state.status = ChargeStatus::Charging;
                             } else {
-                                state.status = ChargeStatus::Charged;
+                                let now = Time::new().get_time();
+                                if state.charge_deadline_at == Duration::ZERO {
+                                    state.charge_deadline_at = now + Duration::from_secs(600);
+                                } else if now > state.charge_deadline_at {
+                                    state.status = ChargeStatus::Charged;
+                                } else {
+                                    state.status = ChargeStatus::Charging;
+                                }
                             }
                         }
                         ChargeStatus::Charged => {