diff --git a/esphome/components/atc_mithermometer/atc_mithermometer.cpp b/esphome/components/atc_mithermometer/atc_mithermometer.cpp
index 293133d56e..9e0b9d018b 100644
--- a/esphome/components/atc_mithermometer/atc_mithermometer.cpp
+++ b/esphome/components/atc_mithermometer/atc_mithermometer.cpp
@@ -73,12 +73,12 @@ optional<ParseResult> ATCMiThermometer::parse_header(const esp32_ble_tracker::Se
 
 bool ATCMiThermometer::parse_message(const std::vector<uint8_t> &message, ParseResult &result) {
 
-  // Byte 5-10 mac in correct order
-  // Byte 11-12 Temperature in uint16
-  // Byte 13 Humidity in percent
-  // Byte 14 Battery in percent
-  // Byte 15-16 Battery in mV uint16_t
-  // Byte 17 frame packet counter
+  // Byte 0-5 mac in correct order
+  // Byte 6-7 Temperature in uint16
+  // Byte 8 Humidity in percent
+  // Byte 9 Battery in percent
+  // Byte 10-11 Battery in mV uint16_t
+  // Byte 12 frame packet counter
 
   const uint8_t *data = message.data();
   const int data_length = 13;
@@ -92,11 +92,12 @@ bool ATCMiThermometer::parse_message(const std::vector<uint8_t> &message, ParseR
   const int16_t temperature = uint16_t(data[7]) | (uint16_t(data[6]) << 8);
   result.temperature = temperature / 10.0f;
 
-  // humidity, 1 byte, 8-bit unsigned integer, 1 %
+  // humidity, 1 byte, 8-bit unsigned integer, 0.1 %
   result.humidity = data[8];
 
-  // battery, 1 byte, 8-bit unsigned integer, 1 %
-  result.battery_level = data[9];
+  // battery, 1 byte, 8-bit unsigned integer,  0.001 V
+  const int16_t battery_level = uint16_t(data[11]) | (uint16_t(data[10]) << 8);
+  result.battery_level = battery_level / 1.0e3f;
 
   return true;
 }
@@ -110,13 +111,13 @@ bool ATCMiThermometer::report_results(const optional<ParseResult> &result, const
   ESP_LOGD(TAG, "Got ATC MiThermometer (%s):", address.c_str());
 
   if (result->temperature.has_value()) {
-    ESP_LOGD(TAG, "  Temperature: %.1f°C", *result->temperature);
+    ESP_LOGD(TAG, "  Temperature: %.1f °C", *result->temperature);
   }
   if (result->humidity.has_value()) {
-    ESP_LOGD(TAG, "  Humidity: %.1f%%", *result->humidity);
+    ESP_LOGD(TAG, "  Humidity: %.1f %%", *result->humidity);
   }
   if (result->battery_level.has_value()) {
-    ESP_LOGD(TAG, "  Battery Level: %.0f%%", *result->battery_level);
+    ESP_LOGD(TAG, "  Battery Level: %.3f V", *result->battery_level);
   }
 
   return true;
diff --git a/esphome/components/atc_mithermometer/sensor.py b/esphome/components/atc_mithermometer/sensor.py
index c4f2dbb1c1..3c98c2367c 100644
--- a/esphome/components/atc_mithermometer/sensor.py
+++ b/esphome/components/atc_mithermometer/sensor.py
@@ -2,7 +2,8 @@ import esphome.codegen as cg
 import esphome.config_validation as cv
 from esphome.components import sensor, esp32_ble_tracker
 from esphome.const import CONF_BATTERY_LEVEL, CONF_HUMIDITY, CONF_MAC_ADDRESS, CONF_TEMPERATURE, \
-    UNIT_CELSIUS, ICON_THERMOMETER, UNIT_PERCENT, ICON_WATER_PERCENT, ICON_BATTERY, CONF_ID
+    UNIT_CELSIUS, ICON_THERMOMETER, UNIT_PERCENT, ICON_WATER_PERCENT, ICON_BATTERY, CONF_ID, \
+    UNIT_VOLT
 
 DEPENDENCIES = ['esp32_ble_tracker']
 
@@ -15,8 +16,8 @@ CONFIG_SCHEMA = cv.Schema({
     cv.GenerateID(): cv.declare_id(ATCMiThermometer),
     cv.Required(CONF_MAC_ADDRESS): cv.mac_address,
     cv.Optional(CONF_TEMPERATURE): sensor.sensor_schema(UNIT_CELSIUS, ICON_THERMOMETER, 1),
-    cv.Optional(CONF_HUMIDITY): sensor.sensor_schema(UNIT_PERCENT, ICON_WATER_PERCENT, 0),
-    cv.Optional(CONF_BATTERY_LEVEL): sensor.sensor_schema(UNIT_PERCENT, ICON_BATTERY, 0),
+    cv.Optional(CONF_HUMIDITY): sensor.sensor_schema(UNIT_PERCENT, ICON_WATER_PERCENT, 1),
+    cv.Optional(CONF_BATTERY_LEVEL): sensor.sensor_schema(UNIT_VOLT, ICON_BATTERY, 3),
 }).extend(esp32_ble_tracker.ESP_BLE_DEVICE_SCHEMA).extend(cv.COMPONENT_SCHEMA)