diff --git a/esphome/components/atc_mithermometer/atc_mithermometer.cpp b/esphome/components/atc_mithermometer/atc_mithermometer.cpp
index 2016b435d4..a372b9f037 100644
--- a/esphome/components/atc_mithermometer/atc_mithermometer.cpp
+++ b/esphome/components/atc_mithermometer/atc_mithermometer.cpp
@@ -13,6 +13,7 @@ void ATCMiThermometer::dump_config() {
   LOG_SENSOR("  ", "Temperature", this->temperature_);
   LOG_SENSOR("  ", "Humidity", this->humidity_);
   LOG_SENSOR("  ", "Battery Level", this->battery_level_);
+  LOG_SENSOR("  ", "Battery Voltage", this->battery_voltage_);
 }
 
 bool ATCMiThermometer::parse_device(const esp32_ble_tracker::ESPBTDevice &device) {
@@ -40,6 +41,8 @@ bool ATCMiThermometer::parse_device(const esp32_ble_tracker::ESPBTDevice &device
       this->humidity_->publish_state(*res->humidity);
     if (res->battery_level.has_value() && this->battery_level_ != nullptr)
       this->battery_level_->publish_state(*res->battery_level);
+    if (res->battery_voltage.has_value() && this->battery_voltage_ != nullptr)
+      this->battery_voltage_->publish_state(*res->battery_voltage);
     success = true;
   }
 
@@ -72,7 +75,6 @@ optional<ParseResult> ATCMiThermometer::parse_header(const esp32_ble_tracker::Se
 }
 
 bool ATCMiThermometer::parse_message(const std::vector<uint8_t> &message, ParseResult &result) {
-
   // Byte 0-5 mac in correct order
   // Byte 6-7 Temperature in uint16
   // Byte 8 Humidity in percent
@@ -99,8 +101,8 @@ bool ATCMiThermometer::parse_message(const std::vector<uint8_t> &message, ParseR
   result.battery_level = data[9];
 
   // battery, 2 bytes, 16-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;
+  const int16_t battery_voltage = uint16_t(data[11]) | (uint16_t(data[10]) << 8);
+  result.battery_voltage = battery_voltage / 1.0e3f;
 
   return true;
 }
@@ -122,6 +124,9 @@ bool ATCMiThermometer::report_results(const optional<ParseResult> &result, const
   if (result->battery_level.has_value()) {
     ESP_LOGD(TAG, "  Battery Level: %.0f %%", *result->battery_level);
   }
+  if (result->battery_voltage.has_value()) {
+    ESP_LOGD(TAG, "  Battery Voltage: %.3f V", *result->battery_voltage);
+  }
 
   return true;
 }
diff --git a/esphome/components/atc_mithermometer/atc_mithermometer.h b/esphome/components/atc_mithermometer/atc_mithermometer.h
index 07bdd40ae2..bdf66d9cf5 100644
--- a/esphome/components/atc_mithermometer/atc_mithermometer.h
+++ b/esphome/components/atc_mithermometer/atc_mithermometer.h
@@ -13,6 +13,7 @@ struct ParseResult {
   optional<float> temperature;
   optional<float> humidity;
   optional<float> battery_level;
+  optional<float> battery_voltage;
   bool is_duplicate;
   int raw_offset;
 };
@@ -27,6 +28,7 @@ class ATCMiThermometer : public Component, public esp32_ble_tracker::ESPBTDevice
   void set_temperature(sensor::Sensor *temperature) { temperature_ = temperature; }
   void set_humidity(sensor::Sensor *humidity) { humidity_ = humidity; }
   void set_battery_level(sensor::Sensor *battery_level) { battery_level_ = battery_level; }
+  void set_battery_voltage(sensor::Sensor *battery_voltage) { battery_voltage_ = battery_voltage; }
 
   optional<ParseResult> parse_header(const esp32_ble_tracker::ServiceData &service_data);
   bool parse_message(const std::vector<uint8_t> &message, ParseResult &result);
@@ -37,6 +39,7 @@ class ATCMiThermometer : public Component, public esp32_ble_tracker::ESPBTDevice
   sensor::Sensor *temperature_{nullptr};
   sensor::Sensor *humidity_{nullptr};
   sensor::Sensor *battery_level_{nullptr};
+  sensor::Sensor *battery_voltage_{nullptr};
 };
 
 }  // namespace atc_mithermometer
diff --git a/esphome/components/atc_mithermometer/sensor.py b/esphome/components/atc_mithermometer/sensor.py
index c4f2dbb1c1..d83e176547 100644
--- a/esphome/components/atc_mithermometer/sensor.py
+++ b/esphome/components/atc_mithermometer/sensor.py
@@ -1,8 +1,9 @@
 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
+from esphome.const import CONF_BATTERY_LEVEL, CONF_BATTERY_VOLTAGE, CONF_MAC_ADDRESS, \
+    CONF_HUMIDITY, CONF_TEMPERATURE, CONF_ID, UNIT_CELSIUS, UNIT_PERCENT, UNIT_VOLT, \
+    ICON_BATTERY, ICON_THERMOMETER, ICON_WATER_PERCENT
 
 DEPENDENCIES = ['esp32_ble_tracker']
 
@@ -17,6 +18,7 @@ CONFIG_SCHEMA = cv.Schema({
     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_BATTERY_VOLTAGE): sensor.sensor_schema(UNIT_VOLT, ICON_BATTERY, 3),
 }).extend(esp32_ble_tracker.ESP_BLE_DEVICE_SCHEMA).extend(cv.COMPONENT_SCHEMA)
 
 
@@ -36,3 +38,6 @@ def to_code(config):
     if CONF_BATTERY_LEVEL in config:
         sens = yield sensor.new_sensor(config[CONF_BATTERY_LEVEL])
         cg.add(var.set_battery_level(sens))
+    if CONF_BATTERY_VOLTAGE in config:
+        sens = yield sensor.new_sensor(config[CONF_BATTERY_VOLTAGE])
+        cg.add(var.set_battery_voltage(sens))