diff --git a/.gitignore b/.gitignore
index a5309e6..04ea576 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 build*/
+external*/
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 81e8c06..8969bc3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,4 +1,9 @@
 cmake_minimum_required(VERSION 3.20.0)
+
+if(EXISTS "E:/extra/modules/ip5305")
+  list(APPEND ZEPHYR_EXTRA_MODULES "E:/extra/modules/ip5305")
+endif()
+
 find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
 
 project(new_kbd)
@@ -8,7 +13,9 @@ zephyr_include_directories(${CMAKE_CURRENT_SOURCE_DIR}/src/events)
 
 target_sources(app PRIVATE
     src/main.c
+    src/events/battery_status_event.c
     src/events/mode_event.c
+    src/modules/battery_module.c
     src/modules/button_map_module.c
     src/modules/mode_switch_module.c
 )
diff --git a/app.overlay b/app.overlay
index 21872e9..f57dfdb 100644
--- a/app.overlay
+++ b/app.overlay
@@ -1,5 +1,8 @@
+#include <zephyr/dt-bindings/gpio/gpio.h>
+
 / {
     zephyr,user {
+        vbat-en-gpios = <&gpio0 9 GPIO_ACTIVE_HIGH>;
         io-channels = <&adc 5>, <&adc 7>;
     };
 };
@@ -24,3 +27,13 @@
 &adc {
     status = "okay";
 };
+
+&i2c1 {
+	status = "okay";
+
+	ip5305: pmic@75 {
+		status = "okay";
+		/* 试验项：调整 IP5305 KEY 保活周期，观察 I2C 失败窗口是否随周期移动。 */
+		keepalive-interval-ms = <10000>;
+	};
+};
diff --git a/prj.conf b/prj.conf
index eef80bc..94bc21f 100644
--- a/prj.conf
+++ b/prj.conf
@@ -12,6 +12,7 @@ CONFIG_CAF_POWER_MANAGER=y
 CONFIG_CAF_POWER_MANAGER_TIMEOUT=20
 CONFIG_CAF_POWER_MANAGER_ERROR_TIMEOUT=10
 CONFIG_REBOOT=y
+CONFIG_CAF_KEEP_ALIVE_EVENTS=y
 
 CONFIG_CAF_BUTTONS=y
 CONFIG_CAF_BUTTONS_DEF_PATH="buttons_def.h"
@@ -19,3 +20,5 @@ CONFIG_CAF_BUTTONS_SCAN_INTERVAL=5
 CONFIG_CAF_BUTTONS_DEBOUNCE_INTERVAL=10
 
 CONFIG_ADC=y
+CONFIG_I2C=y
+CONFIG_IP5305=y
diff --git a/src/events/battery_status_event.c b/src/events/battery_status_event.c
new file mode 100644
index 0000000..984a169
--- /dev/null
+++ b/src/events/battery_status_event.c
@@ -0,0 +1,34 @@
+#include "battery_status_event.h"
+
+static void log_battery_status_event(const struct app_event_header *aeh)
+{
+	const struct battery_status_event *event = cast_battery_status_event(aeh);
+
+	APP_EVENT_MANAGER_LOG(aeh,
+			      "charging=%u full=%u soc=%u",
+			      event->charging,
+			      event->full,
+			      event->soc);
+}
+
+static void profile_battery_status_event(struct log_event_buf *buf,
+					 const struct app_event_header *aeh)
+{
+	const struct battery_status_event *event = cast_battery_status_event(aeh);
+
+	nrf_profiler_log_encode_uint8(buf, event->charging ? 1U : 0U);
+	nrf_profiler_log_encode_uint8(buf, event->full ? 1U : 0U);
+	nrf_profiler_log_encode_uint8(buf, event->soc);
+}
+
+APP_EVENT_INFO_DEFINE(battery_status_event,
+		      ENCODE(NRF_PROFILER_ARG_U8,
+			     NRF_PROFILER_ARG_U8,
+			     NRF_PROFILER_ARG_U8),
+		      ENCODE("charging", "full", "soc"),
+		      profile_battery_status_event);
+
+APP_EVENT_TYPE_DEFINE(battery_status_event,
+		      log_battery_status_event,
+		      &battery_status_event_info,
+		      APP_EVENT_FLAGS_CREATE(APP_EVENT_TYPE_FLAGS_INIT_LOG_ENABLE));
diff --git a/src/events/battery_status_event.h b/src/events/battery_status_event.h
new file mode 100644
index 0000000..b41174e
--- /dev/null
+++ b/src/events/battery_status_event.h
@@ -0,0 +1,20 @@
+#ifndef BATTERY_STATUS_EVENT_H
+#define BATTERY_STATUS_EVENT_H
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#include <app_event_manager.h>
+#include <app_event_manager_profiler_tracer.h>
+
+struct battery_status_event
+{
+	struct app_event_header header;
+	bool charging;
+	bool full;
+	uint8_t soc;
+};
+
+APP_EVENT_TYPE_DECLARE(battery_status_event);
+
+#endif
diff --git a/src/modules/battery_module.c b/src/modules/battery_module.c
new file mode 100644
index 0000000..be287e4
--- /dev/null
+++ b/src/modules/battery_module.c
@@ -0,0 +1,345 @@
+#include <errno.h>
+
+#include <zephyr/kernel.h>
+#include <zephyr/device.h>
+#include <zephyr/drivers/adc.h>
+#include <zephyr/drivers/gpio.h>
+#include <zephyr/drivers/power/ip5305.h>
+#include <zephyr/sys/atomic.h>
+#include <zephyr/sys/util.h>
+
+#include <app_event_manager.h>
+#include <caf/events/power_event.h>
+#include <caf/events/power_manager_event.h>
+
+#define MODULE battery
+#include <caf/events/module_state_event.h>
+
+#include "battery_status_event.h"
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(MODULE);
+
+#define BATTERY_USER_NODE DT_PATH(zephyr_user)
+#define BATTERY_ADC_IO_CH_IDX 1
+#define BATTERY_SAMPLE_INTERVAL_MS 1000
+#define BATTERY_VDIV_NUM 2
+#define BATTERY_VDIV_DEN 1
+#define BATTERY_MV_WINDOW_SIZE 10
+
+/*
+ * SOC 估算策略：
+ * 这里采用线性估算，默认把 3.30V 映射为 0%，4.20V 映射为 100%。
+ * 若后续实测曲线和电压分压比例不同，只需调整两个阈值即可。
+ */
+#define BATTERY_EMPTY_MV 3300
+#define BATTERY_FULL_MV  4100
+
+static const struct adc_dt_spec battery_adc =
+	ADC_DT_SPEC_GET_BY_IDX(BATTERY_USER_NODE, BATTERY_ADC_IO_CH_IDX);
+
+/*
+ * 电池采样使能脚从 zephyr,user/vbat-en-gpios 读取，避免把引脚号硬编码在 C 里。
+ * 后续板级改脚位只需改 DTS，不需要改固件代码。
+ */
+static const struct gpio_dt_spec battery_en_gpio =
+	GPIO_DT_SPEC_GET(BATTERY_USER_NODE, vbat_en_gpios);
+
+static const struct device *const ip5305_dev = DEVICE_DT_GET(DT_NODELABEL(ip5305));
+
+struct battery_status
+{
+	bool charging;
+	bool full;
+	uint8_t soc;
+};
+
+static struct k_work_delayable battery_sample_work;
+static int16_t battery_adc_sample_buffer;
+static atomic_t active;
+static struct battery_status last_status;
+static bool has_last_status;
+static int32_t battery_mv_window[BATTERY_MV_WINDOW_SIZE];
+static int64_t battery_mv_sum;
+static size_t battery_mv_count;
+static size_t battery_mv_index;
+
+static void battery_module_resume(void);
+
+static uint8_t soc_from_mv(int32_t mv)
+{
+	if (mv <= BATTERY_EMPTY_MV)
+	{
+		return 0;
+	}
+
+	if (mv >= BATTERY_FULL_MV)
+	{
+		return 100;
+	}
+
+	int32_t soc = ((mv - BATTERY_EMPTY_MV) * 100) / (BATTERY_FULL_MV - BATTERY_EMPTY_MV);
+	return (uint8_t)CLAMP(soc, 0, 100);
+}
+
+static int adc_sample_once_mv(int32_t *mv)
+{
+	struct adc_sequence sequence = {0};
+	int err = adc_sequence_init_dt(&battery_adc, &sequence);
+	if (err)
+	{
+		return err;
+	}
+
+	sequence.buffer = &battery_adc_sample_buffer;
+	sequence.buffer_size = sizeof(battery_adc_sample_buffer);
+
+	err = adc_read_dt(&battery_adc, &sequence);
+	if (err)
+	{
+		LOG_WRN("adc_read_dt failed (err=%d)", err);
+		return err;
+	}
+
+	*mv = battery_adc_sample_buffer;
+	err = adc_raw_to_millivolts_dt(&battery_adc, mv);
+	if (err)
+	{
+		LOG_WRN("adc_raw_to_millivolts_dt failed (err=%d raw=%d)",
+			err, battery_adc_sample_buffer);
+	}
+
+	return err;
+}
+
+static int read_battery_mv(int32_t *mv)
+{
+	int err;
+	int32_t sensed_mv;
+
+	err = adc_sample_once_mv(&sensed_mv);
+	if (err)
+	{
+		return err;
+	}
+
+	/*
+	 * 板级电池检测存在分压，ADC 读到的是分压后电压。
+	 * 这里按分压比还原电池端真实电压，供 SOC 估算与事件上报使用。
+	 */
+	int32_t battery_mv = (sensed_mv * BATTERY_VDIV_NUM) / BATTERY_VDIV_DEN;
+
+	/*
+	 * 使用固定窗口平均抑制采样抖动。
+	 * 窗口未填满前按当前样本数求平均，填满后使用环形缓冲滚动更新。
+	 */
+	if (battery_mv_count < BATTERY_MV_WINDOW_SIZE)
+	{
+		battery_mv_window[battery_mv_index] = battery_mv;
+		battery_mv_sum += battery_mv;
+		battery_mv_count++;
+	}
+	else
+	{
+		battery_mv_sum -= battery_mv_window[battery_mv_index];
+		battery_mv_window[battery_mv_index] = battery_mv;
+		battery_mv_sum += battery_mv;
+	}
+
+	battery_mv_index = (battery_mv_index + 1U) % BATTERY_MV_WINDOW_SIZE;
+	*mv = (int32_t)(battery_mv_sum / (int64_t)battery_mv_count);
+
+	return 0;
+}
+
+static int read_battery_status(struct battery_status *status)
+{
+	int err;
+	int32_t mv;
+
+	err = ip5305_is_charging(ip5305_dev, &status->charging);
+	if (err)
+	{
+		return err;
+	}
+
+	err = ip5305_is_charge_full(ip5305_dev, &status->full);
+	if (err)
+	{
+		return err;
+	}
+
+	err = read_battery_mv(&mv);
+	if (err)
+	{
+		LOG_WRN("read_battery_mv failed (err=%d)", err);
+		return err;
+	}
+
+	status->soc = soc_from_mv(mv);
+	return 0;
+}
+
+static void publish_battery_status_event(const struct battery_status *status)
+{
+	struct battery_status_event *event = new_battery_status_event();
+
+	event->charging = status->charging;
+	event->full = status->full;
+	event->soc = status->soc;
+
+	APP_EVENT_SUBMIT(event);
+}
+
+static void battery_sample_fn(struct k_work *work)
+{
+	ARG_UNUSED(work);
+
+	if (!atomic_get(&active))
+	{
+		return;
+	}
+
+
+	struct battery_status sampled;
+	int err = read_battery_status(&sampled);
+	if (err)
+	{
+		goto out_reschedule;
+	}
+
+	/*
+	 * 仅在状态发生变化时上报，避免重复事件淹没总线。
+	 * 变化条件：充电标志、满电标志、SOC 任意一个变化。
+	 */
+	if (!has_last_status ||
+	    (sampled.charging != last_status.charging) ||
+	    (sampled.full != last_status.full) ||
+	    (sampled.soc != last_status.soc))
+	{
+		last_status = sampled;
+		has_last_status = true;
+		publish_battery_status_event(&sampled);
+	}
+
+out_reschedule:
+	k_work_reschedule(&battery_sample_work, K_MSEC(BATTERY_SAMPLE_INTERVAL_MS));
+}
+
+static int battery_module_init(void)
+{
+	if (!device_is_ready(ip5305_dev))
+	{
+		LOG_ERR("IP5305 device not ready");
+		return -ENODEV;
+	}
+
+	if (!adc_is_ready_dt(&battery_adc))
+	{
+		LOG_ERR("Battery ADC device not ready");
+		return -ENODEV;
+	}
+
+	if (!device_is_ready(battery_en_gpio.port))
+	{
+		LOG_ERR("Battery EN GPIO device not ready");
+		return -ENODEV;
+	}
+
+	int err = gpio_pin_configure_dt(&battery_en_gpio, GPIO_OUTPUT_INACTIVE);
+	if (err)
+	{
+		LOG_ERR("Battery EN GPIO configure failed (err=%d)", err);
+		return err;
+	}
+
+	err = adc_channel_setup_dt(&battery_adc);
+	if (err)
+	{
+		LOG_ERR("Battery ADC channel setup failed (err=%d)", err);
+		return err;
+	}
+
+	/*
+	 * 按需求将最深电源级别限制在 SUSPENDED，禁止进入 OFF。
+	 * 这样即使 CPU 进入挂起，IP5305 的硬件保活后端仍可持续输出保活脉冲。
+	 */
+	power_manager_restrict(MODULE_IDX(MODULE), POWER_MANAGER_LEVEL_SUSPENDED);
+
+	k_work_init_delayable(&battery_sample_work, battery_sample_fn);
+	has_last_status = false;
+	battery_mv_sum = 0;
+	battery_mv_count = 0;
+	battery_mv_index = 0;
+	atomic_set(&active, false);
+
+	atomic_set(&active, true);
+	(void)gpio_pin_set_dt(&battery_en_gpio, 1);
+	k_work_reschedule(&battery_sample_work, K_NO_WAIT);
+
+	return 0;
+}
+
+static void battery_module_suspend(void)
+{
+	atomic_set(&active, false);
+	(void)k_work_cancel_delayable(&battery_sample_work);
+	(void)gpio_pin_set_dt(&battery_en_gpio, 0);
+	module_set_state(MODULE_STATE_STANDBY);
+}
+
+static void battery_module_resume(void)
+{
+	if (atomic_get(&active))
+	{
+		return;
+	}
+
+	atomic_set(&active, true);
+	(void)gpio_pin_set_dt(&battery_en_gpio, 1);
+	k_work_reschedule(&battery_sample_work, K_NO_WAIT);
+	module_set_state(MODULE_STATE_READY);
+}
+
+static bool app_event_handler(const struct app_event_header *aeh)
+{
+	if (is_module_state_event(aeh))
+	{
+		const struct module_state_event *event = cast_module_state_event(aeh);
+
+		if (check_state(event, MODULE_ID(main), MODULE_STATE_READY))
+		{
+			int err = battery_module_init();
+			if (err)
+			{
+				module_set_state(MODULE_STATE_ERROR);
+			}
+			else
+			{
+				module_set_state(MODULE_STATE_READY);
+			}
+		}
+
+		return false;
+	}
+
+	if (is_power_down_event(aeh))
+	{
+		battery_module_suspend();
+		return false;
+	}
+
+	if (is_wake_up_event(aeh))
+	{
+		battery_module_resume();
+		return false;
+	}
+
+	__ASSERT_NO_MSG(false);
+	return false;
+}
+
+APP_EVENT_LISTENER(MODULE, app_event_handler);
+APP_EVENT_SUBSCRIBE(MODULE, module_state_event);
+APP_EVENT_SUBSCRIBE_EARLY(MODULE, power_down_event);
+APP_EVENT_SUBSCRIBE(MODULE, wake_up_event);