Method of charging plurality of battery cells and controller for performing the method
A battery charging circuit for charging batteries includes a first switch connected in series between a first pole of a power supply and a first pole of the first battery cell, a second switch connected in parallel between the first pole of the first battery cell and a second pole of the first battery cell configured to adjust a size of a current applied to the first battery cell, a third switch connected in parallel between a first pole of the second battery cell and a second pole of the second battery cell, the third switch being configured to adjust a size of a current applied to the second battery cell, and a fourth switch connected in series between the second pole of the first battery cell and the first pole of the second battery cell.
1. A method of charging a plurality of battery cells by controlling a battery charging circuit connected to the plurality of battery cells, the method comprising:
obtaining first state information for a first battery cell of the plurality of battery cells and second state information for a second battery cell of the plurality of battery cells;
determining a first charging profile for the first battery cell based on the first state information and determining a second charging profile for the second battery cell based on the second state information;
determining a first mode for charging the first battery cell based on the first charging profile and determining a second mode for charging the second battery cell based on the second charging profile; and
controlling the battery charging circuit by controlling at least one of a first switch, a second switch, a third switch, and a fourth switch based on the first mode and the second mode,
wherein the battery charging circuit comprises:
the first switch being connected in series between a first pole of a power supply and a first pole of the first battery cell;
the second switch being connected in parallel between the first pole of the first battery cell and a second pole of the first battery cell, the second switch being configured to adjust a size of a current applied to the first battery cell;
the third switch being connected in series with the second switch and in parallel between a first pole of the second battery cell and a second pole of the second battery cell, the third switch being configured to adjust a size of a current applied to the second battery cell, the third switch connecting in series the second pole of the first battery cell and a ground connected to the second pole of the second battery cell, and a second pole of the power supply connected to the ground; and
the fourth switch being connected in series between the second pole of the first battery cell and the first pole of the second battery cell.
2. The method of claim 1 , wherein the obtaining each of the first state information for the first battery cell and the second state information for the second battery cell comprises obtaining the first state information by modeling a physical phenomenon in the first battery cell and the second battery cell, respectively, using a battery model.
3. The method of claim 1 , further comprising:
dividing a charging process of the first battery cell into charging stages,
wherein the first charging profile comprises information for charging the first battery cell with at least one of a charging current or a charging voltage corresponding to each charging stage of the charging stages.
4. The method of claim 1 , wherein the controlling of the battery charging circuit comprises:
generating a first pulse width modulation (PWM) signal to control the second switch such that the first battery cell is charged in the first mode; and
controlling the second switch based on the first PWM signal.
5. The method of claim 1 , wherein the controlling of the battery charging circuit comprises:
determining whether a first charging current value for charging the first battery cell corresponds to a first threshold current value; and
terminating charging of the first battery cell, in response to the first charging current value corresponds to the preset first threshold current value.
6. The method of claim 1 , further comprising:
generating circuit safety information by measuring at least one of a current, a voltage, and a temperature applied to the battery charging circuit using at least one sensor; and
opening the battery charging circuit through a protection switch of the battery charging circuit, in response to the circuit safety information being greater than a threshold.
7. The method of claim 1 , wherein the battery charging circuit further comprises the third switch connecting in series the first switch and the ground.
8. The method of claim 1 , wherein the adjustment of the size of the current applied to the first battery cell, with the first switch being connected in parallel between the first pole of the first battery cell and the second pole of the first battery cell, comprises applying a first current to the first battery cell according to a first duty ratio that is dependent on a first signal controlling the first switch, and applying a different second current to the first battery cell according to a different second duty ratio that is dependent on a different second signal controlling the first switch.
9. A battery charging device, comprising:
a battery charging circuit connected to a first battery cell and a second battery cell; and
a controller configured to control the battery charging circuit, wherein the battery charging circuit comprises:
a first switch connected in series between a first pole of a power supply and a first pole of the first battery cell;
a second switch connected in parallel between the first pole of the first battery cell and a second pole of the first battery cell configured to adjust a size of a current applied to the first battery cell;
a third switch connected in series with the second switch and in parallel between a first pole of the second battery cell and a second pole of the second battery cell, the third switch being configured to adjust a size of a current applied to the second battery cell, the third switch connecting in series between the second pole of the first battery cell and a ground connected to the second pole of the second battery cell and a second pole of the power supply connected to the ground; and
a fourth switch connected in series between the second pole of the first battery cell and the first pole of the second battery cell.
10. The battery charging device of claim 9 , wherein the controller comprises a microprocessor.
11. The battery charging device of claim 9 , wherein the first battery cell and the second battery cell are heterogeneous.
12. The battery charging device of claim 11 , wherein the first battery cell and the second battery cell each have a different capacity.
13. The battery charging device of claim 9 , wherein the first battery cell and the second battery cell are connected in series by the fourth switch closing during charging.
14. The battery charging device of claim 13 , wherein a voltage applied to both poles of the power supply is a sum of a voltage of the first battery cell and a voltage of the second battery cell, in response to the first battery cell and the second battery cell being connected in series.
15. The battery charging device of claim 9 , wherein the controller is configured to:
generate a first pulse width modulation (PWM) signal configured to charge the first battery cell and a second PWM signal configured to charge the second battery cell; and
independently control the second switch and the third switch based on the first PWM signal and the second PWM signal.
16. The battery charging device of claim 15 , wherein the battery charging circuit further comprises:
a first low-pass filter configured to reduce a voltage ripple that appears by the second switch being controlled based on the first PWM signal, the first low-pass filter comprising a coil and a capacitor.
17. The battery charging device of claim 16 , wherein the first low-pass filter further comprises a diode configured to prevent a reverse current.
18. The battery charging device of claim 15 , wherein the battery charging circuit further comprises:
a protection switch;
at least one sensor configured to generate circuit safety information by measuring at least one of a current, a voltage, or a temperature applied to the battery charging circuit; and
a circuit protection module configured to open the battery charging circuit through the protection switch, in response to the circuit safety information being greater than a threshold.
19. The battery charging device of claim 9 , wherein the battery charging circuit further comprises a balancing circuit for the first battery cell and the second battery cell,
wherein the balancing circuit comprises:
a first balance diode connected to the first battery cell;
a second balance diode connected to the second battery cell; and
a load,
wherein the controller is configured to control the first balance diode and the second balance diode through a diode enable signal.
20. The battery charging device of claim 9 , wherein the battery charging device is comprised in a vehicle or a mobile terminal.