Parallel battery architecture with shared bidirectional converter

1. A power source, comprising:

a set of cells;

a main power bus configured to connect the set of cells in a parallel configuration;

a bidirectional converter configured to connect to one cell from the set of cells at a time; and

a set of switches configured to connect one cell at a time through a corresponding switch to the bidirectional converter and connect the remaining cells through corresponding switches to the main power bus.

2. The power source of claim 1 , wherein the bidirectional converter corresponds to a buck-boost converter.

3. The power source of claim 2 , wherein the buck-boost converter comprises an inductor and four field-effect transistors (FETs).

4. The power source of claim 1 , wherein the set of switches are further configured to switch a given cell in the set of cells from the main power bus to the bidirectional converter by:

servoing a cell-side voltage of the cell to a voltage of the main power bus;

simultaneously connecting the cell to the main power bus and the bidirectional converter; and

disconnecting the cell from the main power bus.

5. The power source of claim 1 , wherein the set of switches are further configured to switch a given cell in the set of cells from the bidirectional converter to the main power bus by:

servoing a cell-side voltage of the cell to a voltage of the main power bus;

simultaneously connecting the cell to the main power bus and the bidirectional converter; and

disconnecting the cell from the bidirectional converter.

6. The power source of claim 1 , wherein the bidirectional converter is further configured to perform at least one of:

charging the cell;

discharging the cell;

isolating the cell; and

facilitating the calibration of the cell.

7. The power source of claim 6 , wherein the calibration involves at least one of:

calibrating a state-of-charge of the cell; and

calibrating a capacity of the cell.

8. The power source of claim 7 , wherein calibrating the state-of-charge involves:

measuring an open circuit voltage of the cell.

9. The power source of claim 1 , wherein the set of switches is further configured to disconnect one or more of the cells from the main power bus and the bidirectional converter.

10. A method for providing a power source, comprising:

connecting a set of cells in a parallel configuration;

configuring a set of switches so that one cell at a time is connected through a corresponding switch to a bidirectional converter and the remaining cells are connected through corresponding switches to a main power bus; and

supplying power from the set of cells.

11. The method of claim 10 , wherein the method further comprises switching a cell from the main power bus to the bidirectional converter by:

servoing a cell-side voltage of the cell to a voltage of the main power bus;

simultaneously connecting the cell to the main power bus and the bidirectional converter; and

disconnecting the cell from the main power bus.

12. The method of claim 10 , wherein the method further comprises switching a cell from the bidirectional converter to the main power bus by:

servoing a cell-side voltage of the cell to a voltage of the main power bus;

simultaneously connecting the cell to the main power bus and the bidirectional converter; and

disconnecting the cell form the bidirectional converter.

13. The method of claim 10 , wherein the bidirectional converter is configured to perform at least one of:

charging the cell;

discharging the cell;

isolating the cell; and

facilitating the calibration of the cell.

14. The method of claim 13 , wherein the calibration involves at least one of:

calibrating a state-of-charge of the cell; and

calibrating a capacity of the cell.

15. The method of claim 14 , wherein calibrating the state-of-charge involves:

measuring an open circuit voltage of the cell.

16. The method of claim 10 , wherein the bidirectional converter corresponds to a buck-boost converter.

17. The method of claim 16 , wherein the buck-boost converter comprises an inductor and four field-effect transistors (FETs).

18. The method of claim 10 , further comprising:

disconnecting one or more of the cells from the main power bus and the bidirectional converter.

19. A portable electronic device, comprising:

a set of components powered by a power source; and

the power source, comprising:

a set of cells;

a main power bus configured to connect the set of cells in a parallel configuration;

a bidirectional converter configured to connect to one cell from the set of cells at a time; and

a set of switches configured to connect one cell at a time through a corresponding switch to the bidirectional converter and connect the remaining cells through corresponding switches to the main power bus.