Battery system with heating element and method of controlling the same
Provided is a battery system including a battery management module, a battery module, and a controller. The battery management module includes a main switch between an external terminal and a battery terminal, and a heating switch between the external terminal and a heating terminal. The battery module includes a cell, a heating element, and a control switch connected to the heating element. The controller is configured to detect a connection with a charger, detect a temperature of the cell, when the temperature is lower than a first value, turn off the main switch and turn on the heating switch and the control switch to supply heating power from the charger to the heating element, and when the temperature becomes higher than a second value by the heating element, turn off the heating switch and turn on the main switch to supply charging power from the charger to the cell.
1. A battery system, comprising:
a battery management module including an external terminal, a battery terminal, a heating terminal, a main switch between the external terminal and the battery terminal, and a heating switch between the external terminal and the heating terminal;
at least one battery module including at least one battery cell connected to the battery terminal, a heating element, and a control switch between the heating element and the heating terminal; and
a controller configured to detect connection with a charger, and to detect a cell temperature of the at least one battery cell, wherein:
when the cell temperature is lower than a first reference value, the controller is to turn off the main switch and turn on the heating switch and the control switch to supply heating power from the charger to the heating element, and
when the cell temperature is higher than a second reference value, the controller is to turn off the heating switch and turn on the main switch to supply charging power from the charger to the at least one battery cell, wherein the controller includes:
a microcontroller mounted on the battery management module and configured to control the main switch and the heating switch; and
at least one analog front end respectively mounted on the at least one battery module and configured to detect the cell temperature, transmit the detected cell temperature to the microcontroller, and output a control signal to the control switch according to control of the microcontroller.
2. The battery system as claimed in claim 1 , wherein:
the control signal is a pulse width modulation signal, and
the microcontroller is configured to determine a duty ratio of the control signal according to the cell temperature.
3. The battery system as claimed in claim 2 , wherein the at least one battery module includes:
a first battery module including at least one first battery cell, a first heating element, and a first control switch between the first heating element and the heating terminal; and
a second battery module including at least one second battery cell, a second heating element, and a second control switch between the second heating element and the heating terminal.
4. The battery system as claimed in claim 3 , wherein:
the at least one first battery cell and the at least one second battery cell are connected to each other in series,
the controller is configured to request the charger to supply a heating voltage when one of a first cell temperature of the at least one first battery cell and a second cell temperature of the at least one second battery cell is lower than the first reference value, and
the controller is configured to request the charger to supply a higher charging voltage than the heating voltage when all of the first cell temperature and the second cell temperature are higher than the second reference value.
5. The battery system as claimed in claim 4 , wherein, when the first cell temperature of the at least one first battery cell reaches the second reference value and the second cell temperature of the at least one second battery cell is lower than the second reference value, the controller is configured to output a first control signal having a first duty ratio to the first control switch and output a second control signal having a second duty ratio higher than the first duty ratio to the second control switch.
6. The battery system as claimed in claim 1 , wherein the second reference value is equal to or higher than the first reference value.
7. The battery system as claimed in claim 1 , wherein:
the heating element is a film heater having a plurality of regions with different heating values per unit area, and
the at least one battery cell includes a plurality of battery cells arranged on the film heater.
8. The battery system as claimed in claim 7 , wherein a heating value per unit area of a central region of the film heater is lower than a heating value per unit area of an edge region of the film heater.
9. The battery system as claimed in claim 1 , wherein:
the heating element includes a first film heater, and a second film heater that surrounds at least a portion of the first film heater,
the at least one battery module includes a first control switch between the first film heater and the heating terminal, and a second control switch between the second film heater and the heating terminal, and
the controller is configured to output a second control signal having a higher duty ratio than a duty ratio of a first control signal output to the first control switch, to the second control signal.
10. A method of controlling the battery system as claimed in claim 1 , the method comprising:
detecting a connection with a charger;
detecting a cell temperature of the at least one battery cell;
when the cell temperature is lower than the first reference value, operating the controller to turn off the main switch and turn on the heating switch and the control switch so as to supply the heating power from the charger to the heating element; and
when the cell temperature is higher than the second reference value, operating the controller to turn off the heating switch and turn on the main switch so as to supply the charging power from the charger to the at least one battery cell
controlling, by a microcontroller, the main switch and the heating switch;
transmitting, by at least one analog front end, the detected cell temperature to the microcontroller and outputting a control signal to the control switch according to control of the microcontroller.
11. The method as claimed in claim 10 , wherein the supplying of the heating power from the charger to the heating element includes:
detecting the cell temperature that is lower than the first reference value;
turning off the main switch;
requesting the charger to output a heating voltage;
detecting the heating voltage applied to the external terminal;
turning on the heating switch; and
adjusting a duty ratio of a control signal for controlling the control switch.
12. The method as claimed in claim 10 , wherein the supplying of the charging power from the charger to the at least one battery cell includes:
detecting that the cell temperature is maintained to be higher than the second reference value for a preset time;
turning off the heating switch;
requesting the charger to output a charging voltage;
detecting the charging voltage applied to the external terminal; and
turning on the main switch.